Question
From member Conner:
I was wondering if there is any instance or reason you are aware of where a continuous battery maintainer/desulphator would be bad for AGM batteries? Unfortunately we live on shore power a lot right now, and I wanted to buy a maintainer for our AGM starting batteries to live on, such as this one. [A combined desulphator and charger.]
The distributor said I did not need it, and actually said to not get it. Do you know of any reason why a maintainer/desulphater for AGM batteries, hooked up full time to AGMs, would be harmful? (Full River AGM batteries)
Thank you John for the great follow-up information!
Best,
Conor
Well, I installed one of those desulphators 7 years ago. Have not had one electrical failure on instruments etc. which indicates that the spikes do not harm the electronics.
My first set of LifeLines lasted 6 seasons. I never did a equalizing charge. But they had a comfortable marina life most of the time as I was still working and only had 4 weeks vacation + weekend sailing. The first set of batteries was exchanged prematurely. Would probably lasted another season or two.
The curent set of Lifelines have been in the boat 3 season. These batteries are cycled much harder as we are cruising full time 6 month/year. They are still going strong.
If the desulphator do any good I can not say. But I´m pretty sure it is not doing any damage to batteries or instruments. I totally agree that it can not replace the fact that batteries need to fully charged as often as possible.
As I wrote I have never done a equalizing charge. But what I do is to run the battery charger on absorption voltage 14.4V for 16 hours if the batteries have been discharged a longer period. (More than 2-4 days) I believe this might be why I have been successful not having to do the equalizing charge.
When I had open ventilated batteries I learned quickly by measuring the acid that it take much longer time to charge the batteries 100% than what the manufacturer expected. Battery chargers tend to have absorption time between 4-6 hours. This is many times to short to charge the battery to 100 %. My Mastervolt charger can be programmed to max. 8 hours. Even that is to short if the batteries have been discharged for several day between 50-70%. It takes time to charge a battery properly.
Sorry for derailing a little bit:-)
John
A friend of mine purchased one of these that was solar powered. He connected it to the battery
on his wife’s brand new jeep grand cherokee ( not sure why ). It destroyed the cars E.C.M. She was
not amused. This is just anecdotal but it does give evidence that electronics can be damaged by
the high voltage pulses from these devices even with the battery acting as a buffer.
I ran a couple of Pulsetech PowerPulse desulphators on our last boat, which had a pair of Odyssey 2150s and a single Odyssey 1500 for the starter. I used one unit for both the house batteries and a separate unit for the starter. After 4 years of use the batteries seemed strong without any significant degradation. Its worth reviewing the testing that Pulsetech has done, it seems scientific (to me).
Hi John,
thank you for the deep insights (again). Regarding concerns about the voltage spikes – couldn’t a voltage stabilizer help to reduce the danger? I’m thinking of a separate DC ring for electronics (and other possibly sensitive devices) only that don’t draw a lot of power, a DC ring that is guarded by a stabilizer such as this: https://www.amazon.com/interVOLT-Isolated-Stabilizer-Regulator-Conditioner/dp/B00K8OGBEC