AGM Battery Equalization

[jtsailjt]

Realizing this is an old thread, I benefitted from reading through it so hopefully nobody minds if I add a late data point that pretty much agrees with what’s been said. My situation is that my 4-4D house bank desperately needs to be replaced and the place where I called to get replacements says it’s a 2 month wait but he has Odyssey in stock. I’d REALLY like to switch to LifePo4 but between the price the few qualified installers charge, and the extent of the changes I’d need to make, I just can’t quite talk myself into it yet. Maybe next time. So I searched for what I could learn about Odyssey 4D’s including talking to a very helpful Odyssey tech and it seems pretty interesting. First, they’re $100 cheaper than the Lifelines for each battery.😊They are made of thin plates made of pure lead rather than a combination and are still considered deep cycle. The tech said that it has something to do with the consistency of the material between the plates rather than just the thickness of the plates. I’d never heard that before. I asked why the 20 hour rating of Odyssey was only 170ah but Lifelines ate 210ah and she said she didn’t know but did know that Odyssey rates their batteries conservatively. According to Practical Sailor AGM battery testing, they agree with that statement. Also, in the PS article they found that in 30 cycles of partial charging abuse, the Odyssey lost less capacity than the Lifelines did. I asked about equalizing them and she said they don’t advise charging above 14.8 volts, so that means no equalizing. I’ve been equalizing my Lifelines a few times a year, probably not frequently enough, because I very rarely spend 8 hours plugged into shore power Their Odyssey website encourages charging at .4C so I asked her about that since my house bank will be 680Ah and I’d need a 272 amp.charger to comply and she said that they’d told their engineers nobody has a 300amp charger so they’ve lowered that guidance to .10C minimum but .4C encouraged. Odyssey 4D batteries have lead posts so adapter is needed to convert from the copper tabs Lifeline uses.
Hope something in there helps…..

[sailinglegend]

Originally Posted by jtsailjt

... My situation is that my 4-4D house bank desperately needs to be replaced and the place where I called to get replacements says it’s a 2 month wait but he has Odyssey in stock...

Because AGMs are sealed so can't leak the transport costs are low - so find another dealer who has the stock.

My replacement Lifelines were delivered from the UK to Greece quite cheaply - the old set lasted 14 years as a Liveaboard.

It's worth doing a 20 discharge test on each battery - mine were down to 50% capacity so the test only took 10 hours - they might last 2 months more, or maybe something else is pulling them down. Check each battery in isolation - just one might be dead so disconnect it.

[Tikitour]

I recently bought 3X Lifeline 210amp AGM batteries for my sailboat. I am a full time liveaboard so I am constantly using the batteries. I use a wind generator and 315 watts of solar to charge them and I want to make sure that I am charging them properly. I use roughly 50-60amps during the night and I find most days I am able to top them back up to %100 according to the master volt charge controller. However I am finding that the charge controller never goes into float. Is this a problem even though I have replaced all the owing amps? The charge controller during the day will go between acceptance and bulk charging depending on the charging volts. If a cloud shades out the solar panels it will drop back into bulk and I assume to reach a float status I have to be in acceptance for a measured period of time, which I am not able to reach due to the charge going between bulk and acceptance. My other question is at times I won’t replace all the owing amps because the charge controller will go into acceptance to early and at a decreased rate of charge I cannot replace the owing amps. Is this normal? Also is there anything I need to be doing to maintain my AGMs. Thanks in advance

[Simi 60]

Originally Posted by sailinglegend

Because AGMs are sealed so can't leak the transport costs are low - so find another dealer who has the stock.

.

Yeah, don't know about that

I know I'd rather pay freight on our 120kg of LFP vs the 1000kg + of AGM
Not to mention the cubic metre cost difference

[cal40john]

Originally Posted by Tikitour

I recently bought 3X Lifeline 210amp AGM batteries for my sailboat. I am a full time liveaboard so I am constantly using the batteries. I use a wind generator and 315 watts of solar to charge them and I want to make sure that I am charging them properly. I use roughly 50-60amps during the night and I find most days I am able to top them back up to %100 according to the master volt charge controller. However I am finding that the charge controller never goes into float. Is this a problem even though I have replaced all the owing amps? The charge controller during the day will go between acceptance and bulk charging depending on the charging volts. If a cloud shades out the solar panels it will drop back into bulk and I assume to reach a float status I have to be in acceptance for a measured period of time, which I am not able to reach due to the charge going between bulk and acceptance. My other question is at times I won’t replace all the owing amps because the charge controller will go into acceptance to early and at a decreased rate of charge I cannot replace the owing amps. Is this normal? Also is there anything I need to be doing to maintain my AGMs. Thanks in advance

Probably due to the current you are drawing during the day. If you get a chance turn off everything in the morning and see what happens.