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I am afraid that what you write is spot-on. Really more warning signs than anything else.
thanks for the review
John, I agree with you 100%.
Today before I read your article I watched last video on Delos YT channel. They are building aluminium catamaran and the way how they show it is really nice to watch.
In the last video you can see 2 minutes of Battle Born advertising. The BB page I can’t see anything about CAN bus communication. Only “Compatibility*
with common communication system protocols, including RV-C, NMEA 2000, and more”
And from 270Ah battery you can only draw 100 amps continuously. Not much.
Delos crew plan to use those batteries (50 kWh) for propulsion on that new “expedition” catamaran.
Going back to the topic. I think that nothing was changed. The batteries are unable to control charging sources and loads. You only get fancy app that notify you (or not) that the blackout is coming. And for the propulsion 😉
I really thought that Brian is smarter (from seamanlike point of view).
Mi Michal,
I’m guessing that Brian is getting those batteries for free and it’s possible that on top of that Battle Born pay for time in his videos, both of which tend to trump seamanship. One of my biggest concerns about the YouTube world is that it’s rife with this kind of undisclosed conflict of interest.
I must commend Dragonfly for their efforts, largely successful, to build a North American supply chain for this stuff and to market it successfully.
That said, this specific thing has strong “minimum viable product” vibes.
For example, the hub has a port marked “5V PWR”, implying that whomever designed it lacked the time (or possibly the knowledge) to implement the conversion circuitry required to accept 12V / 24V automatically. It needs a separate converter box to run on the DC power from its own battery.
Another: Someone said “It needs CANbus”. Hardware Engineering replied “ok, here’s a CANbus port” and Software Engineering added “which we will get around to writing code for someday”. The fact that its protocol is not described in the manual means that it doesn’t work. If it did, there would be a chapter describing how to address and configure it, and listing all the message types, bitstream formats, etc. that it could send and receive.
Wireless is nice for monitoring, but it opens up a big attack surface. A physical wired network without external connections can often be treated as a trusted network of trusted devices. The moment you add wireless, the whole thing has to work on a zero-trust model; authentication and validation become real problems, and in the case of a BMS it is indeed possible to set things on fire, cause a total blackout, or otherwise cripple a vessel via the wireless link.
It’s a nice step forward for Dragonfly but I think they are still learning just how much work remains ahead of them.
Hi Matt,
I’m guessing your analysis is dead on.
You are absolutely correct. There are so many instances of “here today, gone tomorrow”… one can see over this happen again and again over time. Having just written this, I am a strong advocate for LFP. We are at approx 700 pack cycles since 2016 on our LFP pack. We bought the cells direct from China. We bought our BMS from Ewert. It has been like ‘magic’ ever since. This was a DIY system. NOW … everyone has ‘jumped onboard’ with their support for LFP. Excellent. But there are definite issues one must consider when using this technology. IMHO, people want to treat LFP like is it Lead Acid tech. BIG MISTAKE. Do your research. Living onboard depends on systems. The energy system ones chooses will define how successful this works out. Trust me.
Hi Deven,
Absolutely agree that Lithium takes a lot more diligence to go well. I wrote a very detailed buyers guide f or just that reason. Six chapter starting here: https://www.morganscloud.com/2024/01/29/lithium-batteries-buyers-guide-part-1-bms-requirements/
If you bought your BMS from Ewert then it is most likely an Orion product. Those are rightly considered to be top tier.
All BMSes are not created equal, and no other component has as big an impact on the overall ownership experience.
Thanks for the review. First generation of anything is always at risk. That said, I replaced my golf cart batteries with drop-in replacement Battleborns, same size and half the weight. They have worked flawlessly for three years now. Just one setting change on my mastervolt controller and that was it. So I trust Battleborn will figure it out with their new series. Given how long my originals will likely last, I don’t have to worry about early adoption 🙂
Hi John,
Glad you have had good service. That said, each to their own, but I would not equip a boat, particularly an offshore boat, with any lithium battery without a BMS that can communicate with charging sources, preferable over CANbus since that’s fast becoming a standard, because of blackout risk: https://www.morganscloud.com/2022/04/25/why-lithium-battery-load-dumps-matter/
As I understand Battle Born’s BMS (and take this with a grain of salt; I am not 100% certain of its exact programming:)
If it senses that the cell voltage is approaching the upper limit while charging, it disconnects the battery. Then it monitors the terminals to see what the charging source does in response.
When the charging source shuts off, then it reconnects the battery, and the loads start running from the battery.
This is perfectly fine, indeed ideal, behaviour for a golf cart, streetlight, forklift, camping trailer, etc.
The problem (as detailed in John’s other articles, see Further Reading) is that boats tend to charge their house banks directly from alternators, which react *very* badly to a sudden disconnect without a “hey there alternator, please shut down your field coils now” first.
And, also, that other critical equipment on board (eg. autopilots) reacts badly to the brief blackout between when the charging source shuts down and when the battery turns back on.
Hence why BMSes aboard boats *MUST*, without exception, be able to command a clean shutdown of external charging services without forcing a battery disconnect.
This will be a controversial opinion, but I feel that the drop in stuff is based on the old two pole acid lead batteries, well duh, it already is implicated in the name, and that anything without a separate solenoid (or electronic switch) for charge and discharge is sub standard.
This can’t be achieved of course by any battery with two (power) poles, the + being used for everything producing or consuming power.
And yes, that is not a drop in solution, as you have to separate the + wiring of the power consumers and power generating devices.
I am testing now on my boat a , what I feel, a way superior system that I designed. To my view it is the next step in really optimizing the Lithium technology for boating not to be shared right now.
(I would be willing to discuss it with AAC under non disclosure agreement.)
Hi Frans,
When you are ready to go public, I would be interested, but not a lot of point telling me under an NDA, given that disclosure is what I do for a living.