Anybody well spoken in LiFePo4 batteries?

Ok, my new battery generator has taken several left turns this last week.

It appears I may have a lemon of a battery.  I checked the voltage and it was sitting at about 9.5 volts, below the normal 10 volt minimum.

I did buy an AC LiFePo4 battery charger that has a repair function.  Does anyone know how discharged a battery need to be to be beyond repair?

Just for background, the battery has never been connected to a load for more than a few seconds at a time and altogether for probably less than of a minute total and only for light loads.  The battery appears undamaged outside, no swelling, etc. and has certainly never gotten warm.  This leads me to think the battery was a dud.  But I also wonder if it can be brought back to life.

My charger on the repair setting takes a whopping 16 hours to run the course.  I hooked it up at 9:00 or 45 minutes ago so it is showing no results at the moment ( though I would not expect it to do so).

Thanks in advance,

Eric

No idea whose brand of LiFePO4 battery is in the device, but I'd determine that and hit their website or support mechanism, and see what they have to say.

It sounds like it needs "waking up" ... LiFePO4-ease for "too discharged" per it's BMS board. Each battery manufacturer has their own routine for doing this.

My "ampere-time" lifepo4's have had one issue where a BMS in a battery was marginal ... a few times I had to "wake up" that battery, while chasing down support for it; A-T ultimately replaced it, on their dime and just my time. BTW, I think these are great batteries sold by a great company, with location here in the US.

So, it could be:

1. needs waking up

2. bms is marginal, bad

3. something has jiggled inside it; if no warranty to void, just open it up and see what is going on

And finally, just replace it w/ another (better) battery. If no warranty, then go ahead and open it up, and salvage it ... a LiFePO4 cell (or set of cells) might be repurposed into something else, once you dump their case and bms.

Hope this helps ...

Thanks Jt, I think I found my problem.  I think I have a bad cell.  I can get the battery to reliably charge to 9.65-9.7 volts—suspiciously close to 3.2 volts x 3 cells.  There is no warranty so I will be buying a new battery.

Thanks for the feedback though,

Eric

Rebooting this thread with a small lithium battery conundrum...

I have several flashlights and headlamps that I enjoy....almost all use single rechargeable 3.7V 650 mAh batteries to power the LED.  Looking to improve on the longevity of each charge, I bought some lithium rechargeable 3.7V batteries of same size and classification...but rated at 2800 mAh.   I tried one of the new batteries in a flashlight and it worked fine, but eventually needed recharging.  The 650 mAh batteries that came with the flashlight typically require overnight to recharge.  With the new battery in the flashlight as a replacement, I have yet to see it reach full charge after several days of charging.  In addition to the possibility of a bad new battery, might the rate of charge of that flashlight be so low that it might take weeks to charge the new batteries?  Any other ideas?  Thanks!

John,

Are you charging with a charger that is specific to LiFePO4 batteries?  If it is not dedicated to LFE's then they typically charge for VERY long times and when you finally pull them out, they will be discharged almost immediately.  It has to do with the quirky voltage charge/discharge profile of a LiFePO4 battery.

Eric

Eric Hanson wrote:John,

Are you charging with a charger that is specific to LiFePO4 batteries? ....

Thanks for the response and apologies that these are lithium ion and not lithium iron phosphate.  Additionally, I can feel myself drifting into the deeper end of the pool now.  The original battery was an INR16340 which chemistry-wise might be different from the newer LS16340 I purchased...??  Both are 3.7V Li-ION batteries.  The flashlight connects to a USB power source for charging through a cable, so I assume the charging circuit is within the flashlight itself?  So I'm wondering if the circuit is matched with the Ah and chemistry of the battery and maybe the new battery just not compatible.... or maybe it charges so slowly that it really does take several days to recharge the larger batteries...?  Also wondering if purchase of a stand-alone charger would work better for the new batteries.  Thanks, Eric, and let me know if you have additional insights with the extra information provided.

John, essentially yes. The simple chargers that comes with the Lamp will probably not be able to charge the big battery in a reasonable time.
I would suggest to get a separate charger. They are not expensive and then you can charge one battery and use the other in the lamp.

Sebastian Köln wrote:......
I would suggest to get a separate charger. They are not expensive and then you can charge one battery and use the other in the lamp.

Done.....and thank you much for this information!