12v Lifepo4 and charger

[Inxider]

Hi, i just trying to get a 12v Lifepo4 setup for the house just for emergencies. To power 12v marine fan that draw about 0.340mah in low 0.440mah on high.

anyone have any experience with this battery

https://rover.ebay.com/rover/0/0/0?mpre=https%3A%2F%2Fwww.ebay.com%2Fulk%2Fitm%2F263982490140

the price seem great.

also I saw this charger Tecmate OptiMATE TM-291

https://www.amazon.com/dp/B007GRGUJU/ref=cm_sw_r_cp_api_euz6BbSD1VX40

It say it have some type of BMS reset is that something to consider or more like a gimmick.
other charger don

[Mike90250]

My crystal ball sees a fire in your future.

When Li batteries are not managed properly, they fail. When they fail, they mostly burn.

[Inxider]

You say that for the charger or..?

they would mostly be used for small draw applications.
Emergencies or in the garage when I do work on small project from time to time.

They would hardly ever get discharged much.
so I can charge them once a month or every two months.

i am also considering the Headway 12 or 15Ah.

[Mike90250]

Li batteries are destroyed by under or over charging. when you start using cells outside the pre-packed device they ship in, you are on your own virgin ground, and must accept the consequences of your actions.
There is no safe way for me to instruct you how the bare cells can safely be used.

[PNjunction]

I can vouch for the Tecmate Optimate TM-291 in your application. I have no experience with your choice of LiFeP04 batt, but the Optimate will charge it safely.

Unlike a "standard" cc/cv charger, the 291 is really designed for LFP. It knows when a battery exceeds the normal LFP charging parameters and will shut down and error out if it sees anything unusual, whereas a generic lead-acid charger would just keep on trucking. The "bms" reset means that is knows how to *gently* burp cells that may have fallen below any internal bms cutoff back into service. It will also test them after charge when left to do a long-term evaluation.

AND, recovery will take awhile as it should SLOWLY bringing the battery up to 3.2v per cell before allowing for full current to begin. Thus, if your rested voltage is below 12.8v, it will take awhile at very low current before it senses 12.8v, so as not to create an ion-storm at higher levels of discharge, and specifically look for internal resistance problems like shorted dendrites.

Works best with "4-cell" or 4S batteries. The more batteries there are in serial / parallel, then the less effective the overall smarts will be, as a bad cell can more easily hide amongst all the others. Thus, keep your cell-count down for best effect.

Highly recommended. Not your usual "dumb" LFP charger. Note that the "ampmatic" feature means that for small cells (like 2.5ah or so), the charger will cut back on the charge current and not blast the full 5A into it. I've charged between 2.5ah to 20ah batts, and watched it do it's thing.

Unlike a conventional CC/CV charger, once it reaches about 14.2v, it will oscillate between 13.7 and 14.2 with pulses, rather than just do a CV taper. Supposedly this helps balance cells by allowing laggards to charge during the initial charge slope of each pulse. Not perfect, but better than nothing. And again, the more cells you have, the less effective it is.

Even if the battery is total crap, the Tecmate-Optimate is your smartest and safest choice as a "dumb" LFP charger.

[Inxider]

Li batteries are destroyed by under or over charging. when you start using cells outside the pre-packed device they ship in, you are on your own virgin ground, and must accept the consequences of your actions.
There is no safe way for me to instruct you how the bare cells can safely be used.

I think you misread my post I am not trying to disassemble the pack at all no way.

it was more like if anyone have experience with that battery brand as they seem to be inexpensive compared to others.

and then on the charger BMS reset feature. As that seem to be the only charger with such feature.
in case the battery ever get drained to the point the BMS kicks in.

[Inxider]

I can vouch for the Tecmate Optimate TM-291 in your application. I have no experience with your choice of LiFeP04 batt, but the Optimate will charge it safely.

Unlike a "standard" cc/cv charger, the 291 is really designed for LFP. It knows when a battery exceeds the normal LFP charging parameters and will shut down and error out if it sees anything unusual, whereas a generic lead-acid charger would just keep on trucking. The "bms" reset means that is knows how to *gently* burp cells that may have fallen below any internal bms cutoff back into service. It will also test them after charge when left to do a long-term evaluation.

AND, recovery will take awhile as it should SLOWLY bringing the battery up to 3.2v per cell before allowing for full current to begin. Thus, if your rested voltage is below 12.8v, it will take awhile at very low current before it senses 12.8v, so as not to create an ion-storm at higher levels of discharge, and specifically look for internal resistance problems like shorted dendrites.

Works best with "4-cell" or 4S batteries. The more batteries there are in serial / parallel, then the less effective the overall smarts will be, as a bad cell can more easily hide amongst all the others. Thus, keep your cell-count down for best effect.

Highly recommended. Not your usual "dumb" LFP charger. Note that the "ampmatic" feature means that for small cells (like 2.5ah or so), the charger will cut back on the charge current and not blast the full 5A into it. I've charged between 2.5ah to 20ah batts, and watched it do it's thing.

Unlike a conventional CC/CV charger, once it reaches about 14.2v, it will oscillate between 13.7 and 14.2 with pulses, rather than just do a CV taper. Supposedly this helps balance cells by allowing laggards to charge during the initial charge slope of each pulse. Not perfect, but better than nothing. And again, the more cells you have, the less effective it is.

Even if the battery is total crap, the Tecmate-Optimate is your smartest and safest choice as a "dumb" LFP charger.

you just sold one more

There just not much info on this charger out there, reviews.
I will give it a try with my current Lifepo4 and see my current battery only is giving out 1Ah out of 20Ah is a Sun brand the blue one from ebay and other places.
I never abused this battery nor did I ever drained it all the way I think the internal BMS went south.

That why I am looking for a new 12v Lifepo to replace this one.
But the price on the Energized Outdoor seem to good, or it might be because of the low C rating about 20Amp for discharge but that would be more than enough for my usage.