15 replies to this topic

[Wallowa]

Jon,

 

Good suggestions...I still can't wrap my mind around the differing advice concerning the BB battery optimal SOC range; some say keep the battery between 20-90% SOC for maximum service life [Li batteries] and BB says you can go 0-100% SOC without detrimentally affecting the service life....honestly determining if the BB is indeed charged to 100ah capacity is a crap shoot; you align all the stars and make an assumption....all good; from AGM to LiFeP04 was a huge improvement on so many levels that even on the low side of 3,000 charge cycles [equivalent of 0-100ah] this battery will most probably outlast me....

 

Phil

[Jon R]

I think you are correctly assessing the situation. I own a 2014 Volt and of course cell phones and computers so i now have some consumer experience with lithium batteries. The volt has noticeable reduction in capacity at 90k miles and probably 2500 cycles, but still has at least 85% of the original capacity. What kills batteries in the Volts is storing the car with the battery discharged, as people that don’t have a charger at home often do. For camper use of maybe 100 cycles a year I agree that the slight benefit of storing a bit below 100% vs fully charged is probably not something the typical user will notice. I think BB is trying to give the beat advice they know to maximize longevity, but it’s not critical for many of us. When you go to store it, turn off all charging, run the fridge for 1/2 to full day, disconnect the battery, and call it good until Spring.

[Wallowa]

Thanks....I followed you until the "run the fridge"....why?  To not leave the BB at or near 100%?  If that is the reason, why can't or shouldn't the BB be stored at close to 100%?

 

Again, I appreciate this information.

[Vic Harder]

Phil, running the fridge because some pundits say LiFePo4 batteries live longer if stored at 80% charge or less.  That said, BB themselves are NOT worried about longevity.  So, do whatever is easiest.  My BB will last longer than me, pretty sure.

[Wallowa]

Thanks Vic...I posed that very question concerning % of charge in a previous post but never really got a definitive answer.

 

While BB says 0-100% is fine others staunchly say that you should cycle LiFeP04 batteries between 20-80% for longer battery life..

BUT I have yet to see the numbers establishing which charging scheme is actually of the most benefit for extending the number of service cycles...in light of the SOC on my BB being 100% at 13.6 to 14.4 volts and 99% @ 13.4 volts [BB figures] all this may be splitting hairs.

 

Similar question concerning the bulk, absorb and float voltages and rate of charge or why tenths of a volt can be significant; like you say lots of pundits but no real quantitative data to back up the methods...so, I am going with the BB numbers but again, no certainty there either.  Such is life! 

 

Ps...Vic you are a youngster and I am sure will burn through several more BB batteries!

[Jon R]

I was suggesting you could run the battery down a bit before storage by running the fridge for several hours. Sorry if that wasn’t clear.