Ramblin' Ralph
Central California Coast
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I bought a low end 100Ah LiFePo4 a couple of years ago. The manufacturer only listed charge and float voltages on their spec sheet. Later I asked them about absorption and they told me 14.4v. They also said it wasn't on the spec sheet because "it's not that frequently ask by our customer". ![[emoticon]](https://forums.goodsamclub.com/sharedcontent/cfb/images/smile.gif "smile") I never got around to setting my solar controller for absorption. For 2 summers of extended summer travel the battery has performed very well and is only charged by my 225w solar system.
So what is the effect on the battery to not have absorption?
Thanks,
Ralph
Ralph
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2oldman
NM
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Lifepo's don't have an absorption phase. Those are strange responses from the mfr.
* This post was
edited 01/21/23 05:18pm by 2oldman *
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time2roll
Southern California
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At 14.0 to 14.4 bulk volts there is no need for absorption time. Worst case the battery might be 2% or 3% undercharged which will not hurt anything ever.
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Ramblin' Ralph
Central California Coast
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Thank for the info. Glad to know I'm damaging my battery.
Ralph
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pianotuna
Regina, SK, Canada
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Ralph,
Quite the opposite. LiFePo4 do not want to be charged to 100%. They do want to be balanced charged once per month.
Regards, Don
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bighatnohorse
Cave Creek
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pianotuna wrote:Ralph,
Quite the opposite. LiFePo4 do not want to be charged to 100%. They do want to be balanced charged once per month.
Isn't a "balance charge" a 100% charge?
As I recall, it is said that over time, individual component batteries can develop slightly different voltages. Thus, charging the entire battery to a full charge and holding it at full charge for a period of time will equalize the individual component batteries.
Can you clarify?
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pianotuna
Regina, SK, Canada
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Hi,
My (limited) understanding is that there is a specific voltage needed to balance the cells. That is set by the battery management system. I don't know what that number is.
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time2roll
Southern California
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Charging to 14.4 on any regular basis as described by the OP is sufficient to keep the cells balanced. There is no recommendation to periodically change the charging cycle for balancing. Yes if the battery is short charged to 13.6 or less it may or may not get any balancing from the BMS. Could go years like that without issue. The primary time balance can be a critical process is when the battery is first assembled to verify the cells are at the same level to start with.
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3 tons
NV.
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time2roll wrote:Charging to 14.4 on any regular basis as described by the OP is sufficient to keep the cells balanced. There is no recommendation to periodically change the charging cycle for balancing. Yes if the battery is short charged to 13.6 or less it may or may not get any balancing from the BMS. Could go years like that without issue. The primary time balance can be a critical process is when the battery is first assembled to verify the cells are at the same level to start with.
X2….Mythology has it that LFP’s are in someway ‘fussy’ to charge when in fact (except for cold weather charge constraint) the opposite is true…
OP suggest he may have ‘damaged’ his batteries (how so??)…The basics are, don’t exceed 14.6v, don’t equalize, float at or below 13.6v (or not at all), don’t leave on charger for an extended period of time (say, once fully charged), no need for a full charge except for occasional cell re-balancing and (if applicable) SOC meter resynchronizations…
Applying this basic charge regime is a minor price to pay which negates conventional battery maintenance and achieve faster charge recovery times and a far deeper depth of discharge..
3 tons
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Grit dog
Black Diamond, WA
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pianotuna wrote:Ralph,
Quite the opposite. LiFePo4 do not want to be charged to 100%. They do want to be balanced charged once per month.
Correct but they’re not near as needy as described above.
Ralph, just when they are not in use, make sure they are not on a maintenance charge. If there is truly no draw. Ideal condition is NOT fully charged, however it’s only slightly less.
I don’t go out of my way to make sure my LFP batteries are drawn down some for storage nor do I maintenance charge them while not in use.
They probably end up fully charged. Like my MX bike. I’ve hooked up a little charger after it sitting for months 6-8 months even “just to see” and it literally takes 2 min or less to register full charge. (Small battery). Tells me it’s fully charged when I last shut the bike off.
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