Li-ion soon to be price competitive with FLA?
I was recently browsing around in an electronics store and saw one of those portable battery packs for charging iPhones/iPads that had a 10,000 mAh capacity for $20. If I'm doing my math correctly tha...
Forum Discussion
What wizard and landyacht are saying.
You will want four 3.2V LiFePO4 batts in series to get 12V.
LiFePO4 are safe (NOT like the Li ions in most cars and airplanes), and you can use 80% of their rated Ah. So a 130Ah 12V LiFePO4 pack would give 104 usable Ah, roughly equivalent to two 6V golf carts rated at 210 Ah.
Four 3.2V 130Ah cells currently cost about 4*170= 680US$
But then you need a BMS and a low-current contactor/PowerRelay to be sure you do not exceed the 10-90% Ah range. (~125$US for BMS, ~190$US for low-current contactor)
You will also want a Ah meter, as the V is very flat between 10 and 90% Ah making it difficult/impossible to estimate battery status from V (~175$US ?).
So the prices add up! Because of the fixed accessory equipment cost, larger battery banks make more sense to me. I've been tempted, primarily because of their very low weights, but the prices are still too high for me.
Oh, and you will want to ensure that you do not charge the batteries when their temperature drops below freezing. In my case that wouldn't be a problem, but I think PianoTuna rejected them for that, in part.
You will want four 3.2V LiFePO4 batts in series to get 12V.
LiFePO4 are safe (NOT like the Li ions in most cars and airplanes), and you can use 80% of their rated Ah. So a 130Ah 12V LiFePO4 pack would give 104 usable Ah, roughly equivalent to two 6V golf carts rated at 210 Ah.
Four 3.2V 130Ah cells currently cost about 4*170= 680US$
But then you need a BMS and a low-current contactor/PowerRelay to be sure you do not exceed the 10-90% Ah range. (~125$US for BMS, ~190$US for low-current contactor)
You will also want a Ah meter, as the V is very flat between 10 and 90% Ah making it difficult/impossible to estimate battery status from V (~175$US ?).
So the prices add up! Because of the fixed accessory equipment cost, larger battery banks make more sense to me. I've been tempted, primarily because of their very low weights, but the prices are still too high for me.
Oh, and you will want to ensure that you do not charge the batteries when their temperature drops below freezing. In my case that wouldn't be a problem, but I think PianoTuna rejected them for that, in part.
