The Offshore Voyaging Reference Site

WakeSpeed WS500—Best Alternator Regulator for Lead Acid¹ and Lithium Batteries

¹Many people take lead acid to mean liquid filled but, in fact, the term covers AGM, gel, carbon-foam, and liquid filled, which all use fundamentally the same chemistry.

Just over a year ago I wrote a chapter in our Online Book on Electrical Systems For Cruising Boats on the then new Wakespeed WS500 and how excited I was that we cruisers finally had a regulator available that actually knew the state of charge by measuring the actual current (amperage) going into the battery, rather than guessing, like every so-called “smart regulator” has for the last two decades (since the Link 2000R went out of production).

After I wrote that piece the guys at Wakespeed were kind enough to send me a WS500 for evaluation, but since we were selling our McCurdy and Rhodes 56, there was not a lot of point in installing the regulator on her, so it sat in a box in our basement for the last year.

But now I’m in the throes of designing a new DC electrical system, with the WS500 at its core, for our new-to-us J/109, and, as part of that, I wrote to Al, founder and chief designer at Wakespeed, to see what cool things he and Rick, the marketing partner in the operation, have been cooking up over the past year.

Al, who is clearly a guy at the forefront of making this stuff work elegantly, was incredibly generous with his time, answering a bunch of my questions in the form of half-a-dozen emails that, taken together, are a fascinating white paper on the state of battery-charging technology.

Plus, Al was a live-aboard cruiser who understands our needs, not some corporate person interested in milking the last drop of profit out of some so-so gear.

So let’s dig into what’s happening at Wakespeed and the cool stuff I learned from Al, a lot of it about lithium battery systems:

A Regulator For All Of Us

As I discussed in my last article on the WS500, the best thing about Al’s design is that it manages to be:

  • Incredibly feature rich in order to support complex lithium-based systems owned by those who want the very latest and coolest.
  • Just the thing for a simple lead-acid based system for those who want the damned DC system to work reliably and get the job done in the most efficient way possible but who don’t want to worry about all the techie details.

I Just Want To Go Cruising

So for those of you who are charter members of the second group, all you need to do is:

  1. Read or reread my original chapter on the WS500 to find out why it’s by far the best cruiser’s alternator controller.
  2. Buy and install a WS500.
  3. Install a decent alternator.
  4. Install good-quality lead acid batteries.
  5. Set the dip switches on the WS500 for the batteries you selected as documented in the quick start guide.
  6. Stop reading right here and go cruising with a smug smile on your face.

For the rest of us tech-geeks, keep reading:

Login to continue reading (scroll down)

More Articles From Online Book: Electrical Systems For Cruising Boats:

  1. Why Most New-To-Us Boat Electrical Systems Must Be Rebuilt
  2. One Simple Law That Makes Electrical Systems Easy to Understand
  3. How Batteries Charge (Multiple Charging Sources Too)
  4. 5 Safety Tips For Working on Boat DC Electrical Systems
  5. 7 Checks To Stop Our DC Electrical System From Burning Our Boat
  6. Cruising Boat Electrical System Design, Part 1—Loads and Conservation
  7. Cruising Boat Electrical System Design, Part 2—Thinking About Systems
  8. Cruising Boat Electrical System Design, Part 3—Specifying Optimal Battery Bank Size
  9. Balancing Battery Bank and Solar Array Size
  10. The Danger of Voltage Drops From High Current (Amp) Loads
  11. Should Your Boat’s DC Electrical System Be 12 or 24 Volt?—Part 1
  12. Should Your Boat’s DC Electrical System Be 12 or 24 Volt?—Part 2
  13. Battery Bank Separation and Cross-Charging Best Practices
  14. Choosing & Installing Battery Switches
  15. Cross-Bank Battery Charging—Splitters and Relays
  16. Cross-Bank Battery Charging—DC/DC Chargers
  17. 10 Tips To Install An Alternator
  18. Stupid Alternator Regulators Get Smarter…Finally
  19. WakeSpeed WS500—Best Alternator Regulator for Lead Acid¹ and Lithium Batteries
  20. Smart Chargers Are Not That Smart
  21. Replacing Diesel-Generated Electricity With Renewables, Part 1—Loads and Options
  22. Replacing Diesel-Generated Electricity With Renewables, Part 2—Case Studies
  23. Efficient Generator-Based Electrical Systems For Yachts
  24. Battery Bank Size and Generator Run Time, A Case Study
  25. A Simple Way to Decide Between Lithium or Lead-Acid Batteries for a Cruising Boat
  26. Eight Steps to Get Ready For Lithium Batteries
  27. Why Lithium Battery Load Dumps Matter
  28. 8 Tips To Prevent Lithium Battery Black Outs
  29. Building a Seamanlike Lithium Battery System
  30. Lithium Batteries Buyer’s Guide—BMS Requirements
  31. Lithium Batteries Buyer’s Guide—Balancing and Monitoring
  32. Lithium Batteries Buyer’s Guide—Current (Amps) Requirements and Optimal Voltage
  33. Lithium Battery Buyer’s Guide—Fusing
  34. Lithium Buyer’s Guide—Budget: High End System
  35. Lithium Buyer’s Guide—Budget: Economy Options
  36. 11 Steps To Better Lead Acid Battery Life
  37. How Hard Can We Charge Our Lead-Acid Batteries?
  38. How Lead Acid Batteries Get Wrecked and What To Do About It
  39. Equalizing Batteries, The Reality
  40. Renewable Power
  41. Wind Generators
  42. Solar Power
  43. Watt & Sea Hydrogenerator Buyer’s Guide—Cost Performance
  44. Battery Monitors, Part 1—Which Type Is Right For You?
  45. Battery Monitors, Part 2—Recommended Unit
  46. Battery Monitors, Part 3—Calibration and Use
  47. Battery Containment—Part 1
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Svein Hellesø

Hi, I am in pretty much the same situation, trying to decide how to improve the original alternator and battery installation on a Sun Fast 35 with a Yanmar with a 60 A alternator.

One question regarding the WS500 is if also could function a battery monitoring unit, if not as sophisticated as the SG200.

As I understand it, the WS500 “know/understands” battery chemistry, and it would not be unfeasible to export this information by a suitable method (Bluetooth would be nice….)?

Stein Varjord

Hi Svein,
I have no WS500, but have been following the project since well before it was on the market. Every bit of info I’ve gotten hold of indicates great people and a great product. The battery monitor function you ask about has been suggested by others too, as this regulator does use a shunt, just like battery monitors do. At the moment, it can’t do this, and I suspect this will not change anytime soon.

The functionality and electronics of an alternator regulator are not similar to those of a battery monitor. The only common ground is the shunt, as mentioned. It might be possible to use the same shunt as a measurement source for both functions at the same time, but the operations would be two separate items. Perhaps they could be in the same box, but that doesn’t seem to have any benefit. Bluetooth does indeed seem like the right interface.

I spoke to Balmar at the METS a couple of years ago about this functionality, and about the WS500. They then said they are working towards just this. Their present model, the MC-618, came about a year after the talk. It would be an intermediate stage, adding communication between the two, but no proper cooperation. They planned to, a couple of years later, release a regulator that uses the info from the shunt of the SG200 monitor to add current as an element in the regulator, so “it would have all the capabilities of the WS500”. This step hasn’t come yet, but probably will come.

I think adding current info to the regulator is essential and will make theirs much better, but that alone might not be enough to close the gap… There’s a lot of other smarts going on in the WS500. Its communication capabilities is a big part of that.

Svein Hellesø

Thank you for the reply. I was trying to avoid adding another instrument, but agree that the SG200 seems like a good idea.

I look forward to the system design for a new charging system etc. for a J/109, as I think it is would be a nice starting point for a similar system on a Sun Fast 35.

Andre Langevin

Great information on a great product thanks. Victron is currently offering current-based charge with Smart Solar in synchronised charging mode using the BMW-702 battery monitor that provide current information. All information is here:

BUT Victron doesn’t have any “DC charging” solution of which i’m aware. This is sad because they are the dream company to work with offering plenty of solutions but none specific to the sailing world and our challenges. Only way to incorporate Victron current sensing charging to a boat would be to have an AC diesel generator feeding enough chargers connecter to the VE.Smart Networking.

Allen Roberts

John, another good article.
I installed 9 months ago two wakespeeds on my cat which are interconnected to my Lithonics batteries with internal BMS. The regulators and the batteries are interconnected via Canbus. While if I was to do it over again, I would pick the same components, it was not a seamless or painless process. There were a number of bugs to be discovered and I found the team at Wakespeed to be very difficult to work with (perhaps they would say the same about me). Most interactions were met with it is not our problem. When they eventually fixed a problem I had informed them about, they never responded with a thank you for finding this and letting us know. I have heard from other customers with similar interactions.
 Most of the issues have been resolved, but one remaining issue is how the regulator handles Canbus messages from the battery to stop charging. It is my opinion they still have issues here. First if the BMS issues disconnect message (ie it is going to pull the plug in the next second), only the regulator paired with that battery will respond. I think ALL regulators should stop charging (and not restart charging) if ANY battery sends that message. Sedcond, when the BMS sends a message to stop charging (this an early warning message for a disconnect), the regulator goes to “float” which in most cases will result in stop charging. However, if there is a problem with the voltage sense, the regulator will continue to charge as it tries to maintain the battery at the float voltage. In my opinion the regulator should discontinue all charging rather than go to float if it gets this message. Hopefully in a future release Wakespeed corrects these issues. In the meantime, I have connected the external disconnect signal from the batteries to a relay to force the regulators off rather than rely on the Canbus messages to do the job.
As for monitoring, with the Canbus option, it is possible to connect a Canbus via a bridge to the existing boat network or to a wifi bridge so all the status info of the batteries and the regulators can be monitored. It is a really nice feature. 

Allen Roberts


All perfect fair comments. My issue is less about the issues i found, but more how it was it handled. Things that were obviously not working correctly were dismissed as operating to spec. I found there was a lot of resistance to seeing there were problems and absolutely no thank you for helping us. However the larger issue is the regulator still does not follow the RV-C spec for what to do when receiving notification from the BMS of a pending disconnect. The RV-C spec says on reception of a BMS disconnect message (DC source Status 6) all sources should immediately stop charging. That is not what the WS-500 currently does. It only listens to that message from the BMS it is paired with. Furthermore the message from the battery to warn of impending disconnect should also result in stop charging, but instead the regulator goes to float which may or may not stop charging. These problems remain even after 9 months.
Again, I think it is a product I would install again, but if the CANbus is used, at present, external guardrails must be used to prevent the system from damaging BMS disconnect with the alternator under load.

Allen Roberts

The response you were apparently provided highlights the issue I have seen in my interactions with Al. A total stubbornness to own up to a problem. Sigh.
The spec is not vague on this point. This is taken directly from the RV-C spec. “01b – Limit reached Indicates whether DC Source (e.g. battery) has reached its upper operation voltage limit and charging sources should terminate.” Notice that “sources” are plural not singular in the spec.
The problem is 99% of installers are not in position to figure this out and if Wakespeed has takes the position that they will not interact with customers then who is going to solve issues? This is why my problems never got solved. I insisted that problems get solved and Al deflected by asking requests come from the installer who while good was not going to dig into the RV-C spec and see what the answer should be. I don’t expect you to solve this for me or adjudicate, but potential buyers should be aware they might get little or no support from Wakespeed. I communicated with Wakespeed in a very non-confrontational manner, just the facts ( I would be happy to supply you with an example). As I have pointed out in the my initial post, I have heard from other wakespeed purchasers who had similar interactions.

I will also acknowledge that not all the issues with the install were Wakespeed related. As I found out, the battery I selected with the internal BMS also doesn’t follow the spec which requires a 2 second warning prior to disconnect. Instead it gives the disconnect message at the same time as the disconnect which is not very helpful.

As for being early adopters, I couldn’t agree more. I figured Lithium batteries and regulators were a stable mature product in 2021… boy did I learn the hard way they are not. My “complicated” install was two engines, a solar charger, inverter/charger and two batteries. It was certainly not my understanding at the onset this was bleeding edge. What was bleeding edge was the CANbus communication for the regulator and it is still not implemented to the RV-C spec.

Nojan Moshiri

We love our Wakespeed, we installed it before starting our cruise. We are currently on month nine, having left Seattle in 2021 and now in Mexico. I can confirm everything in this article. Find a place to mount it, do a little wiring, flip a few dip switches, and go. I can also confirm that a few shortcomings are frustrating because if there was a bluetooth capability it could be so awesome.

The lack of an easy way to remotely monitor, update, or upgrade the Wakespeed sucks. Yes, you can use a Canbus to NMEA bridge or find a bunch of other ways to do the connections to get data, but I really don’t want more hardware on my boat.

Upgrading the software or checking data is almost as bad as having to deal with the magnetic reed switch (the magic screwdriver of Balmar). I’m a software tech person with 25+ years of tech work under m belt and trying to upgrade the firmware on the Wakespeed made me yank out a bunch of hair. I couldn’t use my Mac (not currently supported), and the Windows machine on the boat is fixed in place, I didn’t have a cable long enough, and the only extension I could fashion used a USB hub that made for a weird port ID on Windows 10, having to deal with Putty, and a command line batch script, and yada yada yada, someone with no experience, or less patience, would never get through this. Finally I had to find a longer cable in Mexico, and got the upgrade to work. This cabling and COM PORT hell, not to mention, having to unscrew the cover of the unit, which I installed in the coolest part of the engine room I could find, meant I also had to do boat yoga to do this job.

Having complained about all that, the charging situation for the alternator is night and day compared to the Balmar, and I love the Wakespeed, even with these updating flaws.

William Pittore

I also have a Mac and needed to interface to a Victron Multiplus charger/inverter over a USB connection. The Victron software at the time was Windows only. I used Virtualbox running an instance of Windows 10 on the Mac to interface over USB to the Victron. Would possibly work in your situation as well.


Marc Dacey

A great article, John. Thanks for going deeper.

Robert Tilley

Couldn’t find your list of lithium battery’s ok with the ws500
umm clew me in.
just starting process of total switch over frm gc bank and old Cummins 105 amp alternator

Charles Starke MD

I had a different experience with this Wakespeed. It was installed by my electronics technician in parallel with the Balmar regulator so we could try it out. When we tried it, it charged and sensed everything correctly but on throttling back the engine, charging stopped. The engine had to be stoped and restarted to restart any charging.
My technician reprogrammed it several times but could not get it to work correctly. I sent it back to Wakespeed and they said they adjusted and reprogrammed it.
Multiple visits by my electronics technician seemed to get it working but it wouldn’t reliably continue charging on throttling back the engine. I had to stop and restart the engine to get it working.
I could not trust it and changed the cable back to the Balmar.

Best wishes,
Charles L Starke
s/v Dawnpiper

Holm Albrecht

Hi John & Phyllis. Great article, thanks for putting this stuff out there.
Quick question.
We are building a new sailboat and need to get smart about many things.
I have been looking at integrel but decided to go with a 24v system instead.
Have you heard of electromaax alternators and their external AT3 regulators. They claim to be the best in the marine Industry. I like their external rectifier approach.

Thinking of 500- 600ah lithionics or firefly batteries with two high output 24V alternators. Either electromaax, APS or mastervolt? Don’t hear that many good things about balmar anymore.
The WS500 seems the most advanced out there.

Cory Hall

I have had a ws500 now for about 6+ months of full time living. I have 700 Amp hrs of drop in lithium and didnt understand the implications of the bms’ cutting off and dumping the alternator field voltage to my system. After some lost electronics and switching my ws500 to charge the starter battery instead of the house and then using 4 Dc-dc chargers to charge the house I have a system that works just ok for a lot of extra money. In my opinion most lithium set ups have internal bms’ so I’m not totally happy with my ws500. Also it’s very difficult with the software to understand what limit the ws500 is hitting when it cuts back on either temp of the alternator or over voltage etc. a cable to a laptop while the engine is in use is a major hassle especially when you have to physically open the ws500 case and connect a cord. I have a 170 amp Balmar alternator and the ws500 has only ever let it deliver 100 due to unknown restrictions because the software is a hassle and I have yet to figure it out. My ws500 was setup by the folks at wakespeed for my specific starter battery and alternator while it was in the shop being repaired for another issue. In all honesty I’m sure I can get it sorted but am now tired of it and have given up.

Charles Starke MD

Hi Cory
I went through the same trials as you and sent it the unit back to Wakespeed for repair and reprogramming to my specific new AGM batteries and Balmar alternator.
I could not get reliable function and I also gave up and went back to my Balmar controller.
Best wishes
Charles L Starke MD
s/v Dawnpiper

Charles Starke MD

Hi John
These are all good suggestions. Thank you. I’ve been frustrated and beating my head against the bulkhead after many visits from an electronic technician and returning the unit to Wakespeed for repair and reprogramming and still finding dysfunction.
We have both been seduced by the theoretical benefits of the Wakespeed but real world experience is the key to nirvana.
Best wishes,
Charles L Starke MD
s/v Dawnpiper

Stein Varjord

Hi Cory,
I understand your frustration, but as you mention, your core problem is having drop-in type lithium batteries, with their BMS etc inside the box. This is an inherently poor design. The only reason it exists on the market is that the customers are used to 12V batteries, so salespeople happily serve a familiar item, even though using separate 3,2v cells and external electronics indisputably is the only smart solution.

Some drop-ins have a method to communicate with external controllers. Notably from serious companies like Victron, Mastervolt and Lithionics. (Comparing them to the market average is an insult to these brands…) The WS500 can communicate natively with Victron equipment, some external BMSes and more, but with dumb and mute batteries… I actually think scam is a fair description. Even with a communication ability, drop-ins are not a good solution, neither for performance, durability and certainly not for price.

If I understand your setup correctly, the right solution for you would probably have been to keep the WS500 charging the house bank, and then connect the start battery in parallel to that via an automatic isolation switch, like a Victron Cyrix or Victron Argo Fet. The battery would easily absorb the voltage spike from a BMS disconnect. This would mean that the lead acid starter battery would perhaps live a bit shorter, as it would probably see a bit too low charge Voltage. That depends on how much internal Voltage loss your drop-in batts have. Some of them ask for high enough Voltages for lead acid to thrive.

Alternatively you could keep the batteries separate and use one small B2B charger to keep the start battery topped up from the house. Then use a Sterling Power Alternator Protect device. A cheap little thing that seems to do the same spike protection job as a connected battery. I have no experience with it, but I’ve heard from trustworthy sources that it works well.

If your 170 Amp alternator gives just 100 Amp, that sounds like less than I’d expect, but it might be that the regulator is set to throttle down at a relatively low temp? A dumb internal regulator would usually throttle down considerably more quite early in the cycle. The rule of thumb is that most alternators can handle up to 80% of their rated power. If this is a small frame alternator (almost all boat alternators are), it could get quite hot at a lower temp. The WS500 has an alternator temp sensor for that purpose.

This is a complicated topic. I may have missed important info and drawn the wrong conclusions. Anyway, I’m certain that this type of problem will become ever more prevalent, as greedy and incompetent salespersons make a gradually larger imprint on the lithium market.

Cory Hall

Thanks for your replies, you are correct on most topics. My two cents. I actually planned for the sterling device and I either fried it or it was doa so I was able to go with dc-dc chargers. Regardless I had to remove it, as it was dead and hard to replace in Canada. Second, while I agree with your opinion on lithium bms, the drop in type are considerably cheaper when I look. Mine are Lynac lithium and have an internal bms, the same Victron battery I’m sure is a lot more! I Iike my ws500 and would not go to the Balmar, I had decent to great service from th3 folks at wakespeed but they have some work to do in my humble opinion. Knowing what I know now, I would most certainly buy individual cells and build an external bms.

Stein Varjord

Hi Cory and John,
It seems like we all have the same views on this. I also agree with the load dump issue John mentions. Most drop-in batteries are sold with the claim that the internal BMS and balancing circuits will take care of the cells, so we don’t have to do anything with the systems we got on the boat, that were made for lead acid batteries. This is the core “drop-in” idea. It’s a total and non disputable lie, always. It’s true that such a battery can survive for a reasonably long time on a boat, enough to void warranty, but performance and durability will certainly be far below what it should have been.

This core fake claim means that the BMS is expected to take care of the charge regulation of the cells. That’s another useless strategy, which leads to the mentioned load dump issues, since that’s the only thing a BMS can do; turn all off when something isn’t right. To get correct charging, we need regulators etc to give the correct voltages at the right times. The BMS is the safety guard. The emergency backup, or fuse. It’s meant to never do anything, just watch that no other item does something wrong.

There are other types of BMS in existence that can indeed do som voltage and current modification, so it can actually correct the incoming power some, but I haven’t seen compelling reasons why to use such an afterthought solution. The charging regulators need to be programmable. They need to monitor the cells directly, and they need to communicate with the BMS. This is a situation where an Alternator Protect device could be a solution. To protect against an event that is expected to never happen.

You’re right that the Victron battery packs are really expensive, but they are also a completely different level. Using their systems properly really works. They’re not sold as drop-ins and the only thing they have in common is that the cells are inside a box. They also mostly don’t have the BMS inside, but it’s connected directly to the outside.

Inside you find Winston cells, which are great, but you can buy them dramatically cheaper separately. The box and the few additional components inside are certainly not worth the extra price. I really like Victron, but I’d never buy their batteries. As most others on the market, they don’t make batteries, just repack them. If you buy separate cells sometime, I think you’ll find that the whole high quality system, including connectors, BMS, and more, will be cheaper that even low end drop-in batteries. With a bit of effort you might even find a lower tag than good AGM.

Cory Hall

Gents, again thanks for your comments. I intentionally didn’t get into too much detail but John called me out…lol he said I wasn’t super geeky and that made me sad. Haha. A Mechanical engineering diploma, and a a double degree in computer science and geographic information sciences along with 30 Pius years work experience might make me a little geeky. 🙂 I just want to sail and not spend my time here in Mexico sorting issues.

Stein Varjord

Hi John and Cory,
Touche. 😀
My intention was absolutely not adding to the pain. Rather trying to give as much info as possible. However, when I type I should reread what has been said further up.

It’s a fact that balancing and all the other stuff, while not hard to perform, still amounts to a daunting task. Most people have to figure out loads of details and then perform them while doubting if they got the right info, or understood it right. Yes, it’s easy, but only if you know how to do it. 😀

John Michaels

All this discussion begs the question if there is a worthwhile external BMS to work with WS500 other than The Victron solution. After all, the entire market of individual cells has gone down substantially (EBay/Amazon), drop-ins are winning the war because they are a lot less dangerous rather than DIY, and there is a “disconnect” between already existing quality battery cells, a missing quality built external BMS, and a WS500.
A huge market potential!!!

Stein Varjord

Hi John M,
REC BMS communicates natively with both the WS500 and Victron equipment. That’s definitely a well established quality BMS maker. Daly can also do that, I think. A Swedish maker has also come with an interesting product, X2. This one also has additional control electronics so it is supposed to work as an actual charger. It uses any other source as a power source only, an modifies the charge sequence. I don’t know how well it does the job, but it’s in use on some long distance cruising boats. Several other makers too, but I’m not in the process now, so I’m not fully updated.

I don’t really think the individual cell market has gone down. There’s less noise on Ebay, Amazon, Aliexpress, etc, but that’s at least partly because there has bee so many scams with used cells etc. All those sources should be seen as reliable as the roulette in a casino… For lithium cells we need to know much more about the entity that provides the cells, and be able to solve potential faults with them, to make sure there won’t be any such faults. There are several good sources no matter where we live, but they have their own customer contact systems, outside of the above mentioned flea markets.

Drop-ins are “winning the war” because that’s what conservative and uninformed customers are used to, and because the salespersons make much more money that way, by upping the price while lowering the quality. There is absolutely nothing in a DIY solution that is more dangerous than with a similar drop-in solution. Arguably the opposite, as single cell voltages are 3,2V while a drop-in battery is 13,3V. In reality, the designation DIY is not really relevant in this context. The DIY install is not significantly harder or more time consuming than installing a drop-in correctly. The difference is that the DIY can actually be installed really well, while a drop-in can only be done fairly ok, if you do much more than the seller claims necessary.

The conclusion is that they are both really DIY, because boats are not yet made for lithium. They all need to be updated and adjusted somehow. That is usually the same even if we want to use lead acid batteries, as most boats are very poorly set up for those too. Anyway, in general we need to have more knowledge than the drop-in pushers have themselves.

Toby Sylvester

Hi John,

I have unfortunately had a very disappointing experience with Wakespeed. I fitted a WS500 last year after reading about it on here, after an initial glitch, due to me transposing the shunt wires, it seemed to work fine but I had the sense wire connected to the original brush box incorporating a built in regulator. 

I was advised by Rick at Wakespeed that I should disable this regulator or it could confuse the WS500, so I fitted another brush box without a regulator and wired that as instructed in the manual, but then there was then no output from the alternator at all. 

I tried to resolve the issue with Rick last November but also found the support extremely disappointing, in fact my emails were just ignored, so I can completely relate to Allen’s comments. No one in the company seemed remotely interested in the problem or helping me resolve it, I tried again this year eventually got passed on to someone a couple of weeks ago who actually responded to my emails and helped me resolve what was a very simple issue. 

It may be a good product but unless you are lucky enough to get it working without any assistance, it is a very frustrating process trying to get any support from the company, I would certainly not go down this road again. 

But wait it gets worse…..although the regulator is now working well, I still need to know if it is still necessary disable the diode trio in the alternator? Again I cannot get an answer from Wakespeed on this, would you know the answer John?

William Murdoch

i believe the diode trio Toby refers to is not a part of the main power diodes that produce the alternator’s output DC, but are rather an auxiliary set of diodes that power the alternator’s internal regulator and field coil.

William Murdoch

Actually, I am not an expert in the subject and should not give advice, but I agree with your earlier advice. “I would strongly suggest you replace that alternator with one designed for external regulation and preferably one that’s rated continues duty.” It can be fun to mess with things that one does not really understand, and sometimes fun is the objective, but built for purpose is usually best.

Toby Sylvester

Hi John,

I appreciate what you are saying, I am sure it can be expensive providing support for a technical product like this, but I also think providing a product without any real detail on how to modify a factory installed alternator, or trouble shoot problems, makes the whole process extremely frustrating in the absence of that technical advice. I would be more than happy to pay for advice if only I could find someone who understood the product.

The Diode Trio issue is a case in point, there is a brief reference to having it disabled on page two of the Wakspeed manual, also in an old Xantrex external regulator manual it says in very bold print ‘Caution if the diode trio is not disconnected extremely high voltages can occur and damage equipment’. I have not been able to get any consistent advise from any Wakespeed distributors or alternator repair technicians on this or find anything on the internet. So where do I go from here if I cannot have a brief conversation with someone at Wakespeed. 

I have sent two emails over the past week to ask if this modification is necessary, without any response, I would much rather keep the alternator intact if possible so in the event of the WS500 failing so I can reinstall the original brush box with its own regulator. 

What I do not understand is that with my P-Type alternator D- is connected to ground and DF only to the positive feed of the WS500 neither brush is connected to D+ so how can the diode trio influence the field voltage? Or might this only be a problem with an N-Type when there is brush connected to D+? 

I am guessing most WS500 units are installed without disabling these diodes as no one seems to know about it, and that is probably what I will stick with, but it is all very unsatisfactory not knowing what might happen if I am wrong! 

Toby Sylvester

Hi John,

Yes, I think both of those options would work well. To be fair to Wakespeed they have given me some support and the main issue was eventually resolved with their help.

At least the unit is working now and I am sure sooner or later I will get a response from them to resolve this current dilemma. As you say I should have not tried to be a cheapskate and bought an alternator set up for external regulation in the first place!

Scott St Clair

John, a couple of points have occurred to me. While it would be nice to have the engine alternator charge lithium batteries to 100%, I think the “box within a box” programming strategy for the WS500 is a pretty good solution. Why? Because most cruising sail boats have other charging sources that are more resilient that alternators. I’m thinking, of course, of solar and inverter/chargers and wind. We can let these other sources provide the last 5%. Further, lithium batteries last longer if they’re NOT fully charged all the time. (See the charging system on your iPhone.) That’s why I program the charging sources on the boats I design systems for to a voltage a couple of tenths LOWER than the acceptance voltage specified for the batteries. In a cruising situation (off the grid, either anchored out or sailing), the batteries in a system will seldom be fully charged in any case.

One other thing: Dragon Energy, the maker of BattleBorn drop in lithium batteries, recently acquired Wakespeed. Perhaps we’ll see a well engineered/integrated drop-in lithium solution soon.

Joerg Esdorn

Hi John, thank you for your great thoughts. I wanted to comment on your statement that lead acid batteries are self limiting the rate of charge they will take. I’m not sure that is correct. Here’s my story. Mastervolt regulator, Mastervolt Gel batteries. On a passage from Albania to Malta, we are motoring at night and the battery temperature monitor goes off: 50C or more. Why? The batteries are hot to the touch so yes, the temperature is more than 50C! I didn’t diagnose the problem until several months later when the same thing happened again. The sensing wire of the regulator was loose on the alternator. Result: the regulator read the voltage as 27V (24V system) when in fact the voltage was 31V! So the alternator kept pumping in the amps into the batteries when they were 100% full.

I had to replace the batteries after this episode although they were only 4 years old. I’ve opted for Lithium batteries from MV with the MV BMS. The BMS limits overcharging and measures voltage at the batteries. I wish I had something similar with the gels! If you’ve had Lithium once, you will never install lead acid again. They are a game changer.

Stein Varjord

Hi John,
An update on the smart external alternator regulator marketplace:
I just noticed a new little article by Rod at Marinehowto:

I still think the Wakespeed WS500 is a great product, but this one, the Arcos Zeus, can apparently do all the same, plus some more.

One example: If you bought one for your 12V alternator system, and later want to change to 24V (or 36 or 48) you just tell the regulator so, in the app. Done. No need to buy anything. User friendliness through the app also seems great.

Rod has been on the advisory comity while it was developed. It starts shipping within about a month. Price seems to be 796 Dollars, if bought from Rod, which I think is nice.

Dan Tisoskey


Could the WS combined with this unit:

be the solve all for charging li and lead?

My research tells me to never combine Li and lead?

Any comments would be appreciated as I am designing a system that will use a WS 500, new alternator (recommended by WS) a starting lead battery that could separated from the house bank with a charge relay. NOTE: LI and one lead would make up the house bank using the battery bank management system. This would allow the engine start bank to disconnect once there is no charging sensed through the relay. Solar charge would be absorbed through the lead once the li battery is fully charged and isolated from the Li through the BBMS?

Sounds good on paper and Clark makes some great points. Any thoughts?



Dan Tisoskey


Thank you for the quick response. I tried to search this product but did not use enough keywords to get a response prior to asking. I should have known this option was already asked and answered on your site. I really like the solution of the loads (most on my boat are all critical – no fridge, inverter, etc…) and I could charge via dc to dc charger. on my last boat, I charged the lead starting bank and used two 30 amp dc to dc charges to charge the house bank. This system worked well but still subjected me to li failure and critical systems going out.

Using your diagram and running all systems on lead, using a dc to dc charge to charge the lead from the lithium, charging the lithium from alternator with WS500 and Victron charge controller. This sounds seamanlike and proper. Could the start battery be charged with another dc to dc charger or charge relay? I think this might be the perfect system?

Dan Tisoskey

Thanks John. I will read and then re-read the chapter.