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Posts: 426
Location: Perryville, MO | Hopefully VMS will chime-in on this one...but anyone with knowledge on the subject have at it.
After years of trying different brands I've become a fan of Interstate for the number of cycles I can expect to get out of them. My boat sees the water 125-150 times per year. The work on the trolling motor varies considerably. My last set of batteries (24 volt trolling motor) lasted just short of four years. That's value I can't complain about, especially when no "regular" deep cycles are rated to cycle that many times.
Alright here comes the question... I had been told that like a sponge it's important to run new batteries down fully (down to 20% or so) before recharging. Training the batteries to accept a full charge. Now I'm reading just the opposite. That I should only run them down 20% or so before giving them a proper (slow amp with a strong finish) charge. Which is it? Seems it changes depending upon who's writing the article.
I understand that batteries should hold a longer charge after 50-150 of the first cycles (that is, after the plates are fully conditioned). Again, I didn't have problems with the last set, so I suppose I'd be crazy not to do what I did last time, but just checking to see if I can do even better.
Second question...just because it relates and perhaps someone would like to enlighten us more: Any benefit in using a battery conditioner (acid/electrolyte additive)? |
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Posts: 5874
| You should never run the batteries down that low. Even 20% is too low. Charge them every time you put the boat up for the night, after a day on the water. No matter what.
Lead acid batteries do not "learn" anything. They don't have memory. That's for metal-nickle-hydride batteries.
Edited by Shep 3/18/2014 10:30 AM
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Posts: 3486
Location: Elk River, Minnesota | Hiya,
I will agree with Shep here as well. Lead-acid batteries for deep cycle use are built to have a slow charge taken out of them and a slow recharge rate as well.
When a battery is discharged significantly, and without getting too technical on what is going on, the lead plates react chemically with the sulfur from the sulfuric acid, creating lead sulfate. The Sulfuric acid loses it's sulfur and becomes primarily water. Thus, when you discharge a long way, you have more potential to lose fluid via evaporation, which will shorten the life of the battery significantly. So...to offset this issue, keeping the battery at 20% charge or above helps prevent this type of situation happening.
Years ago it was assumed that all batteries had a "memory" so to speak, but through many years of testing, experimentation, etc...that was proven false.
After your day of use on the water, plug it in and recharge slowly... Doesn't have to be trickle charged (2 amp or lower) but definitely slower is better overall as your tm draws slowly as well...
Steve |
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Posts: 183
Location: Grand Forks ND | Lead acid batteries should be recharged as soon as possible after use. |
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Posts: 426
Location: Perryville, MO | Thanks Shep and VMS.
Edited by hawkeye9 3/19/2014 9:24 AM
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Posts: 299
Location: Not where I want to be! | Shep & VMS
When you say recharge slow, is 15 amps per bank considered too fast? |
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Posts: 3486
Location: Elk River, Minnesota | Hiya,
15 is pretty much on the high end for recharging but is acceptable. The reason for this is that the way the on-board chargers work for the most part is they have different charging stages and if memory serves me correctly a microprocessor on the charger will adjust the charge rate based upon battery's discharge condition. Not sure all chargers do this, so I think it would be best to refer to the owners manual or website for further information on your particular brand and model of charger.
I will admit, I'm not as "up" on the information for Charging systems as I am on other aspects, so I am hopeful there will be a few others more knowledgable in this realm who will chime in.
Steve |
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Posts: 3486
Location: Elk River, Minnesota | repeat... sorry...
Edited by VMS 3/20/2014 3:32 PM
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Posts: 5874
| wavridr - 3/20/2014 6:10 AM
Shep & VMS
When you say recharge slow, is 15 amps per bank considered too fast?
Steve is right. I'd not go higher than 15A. Heat at the post is the issue. 10A is optimum. |
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Posts: 209
| Thanks for the information I did not know about the memory issue
VMS - 3/18/2014 2:28 PM
Hiya,
I will agree with Shep here as well. Lead-acid batteries for deep cycle use are built to have a slow charge taken out of them and a slow recharge rate as well.
When a battery is discharged significantly, and without getting too technical on what is going on, the lead plates react chemically with the sulfur from the sulfuric acid, creating lead sulfate. The Sulfuric acid loses it's sulfur and becomes primarily water. Thus, when you discharge a long way, you have more potential to lose fluid via evaporation, which will shorten the life of the battery significantly. So...to offset this issue, keeping the battery at 20% charge or above helps prevent this type of situation happening.
Years ago it was assumed that all batteries had a "memory" so to speak, but through many years of testing, experimentation, etc...that was proven false.
After your day of use on the water, plug it in and recharge slowly... Doesn't have to be trickle charged (2 amp or lower) but definitely slower is better overall as your tm draws slowly as well...
Steve |
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Posts: 109
| What about AGM batteries? |
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Posts: 2753
Location: Mauston, Wisconsin | Re. AGM's - Most can typically handle higher charger rates, however, the charger has to have temperature compensation to prevent thermal runaway at temperatures above 77F. If that happens in your boat you won't be happy camper..... You also don't want to equalize them, like you do with a wet-cell battery. Get a charger designed for AGM's. I stay at 15A as a max limit, even though you can push higher on a typical 100AH AGM. For smaller AGM's for portable fish finders, camera's etc. be very careful to not exceed ~ 20% of the AH rating.
A good rule of thumb is your charger should be rated between 5% and and 20% of the AH rating. On a typical 100AH AGM this is between 5A- 20A.
Have fun!
Al |
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