Raisedeyebrows
1 kW
Santa'sLittleHelper said:Can you tell me if it has a BMS or not? If so, is it self-balancing? Do you know what the continuous and peak amp output are?
Yeah, they were $119OBO, then he raised them to $129OBO. I offered him $100 and he countered, but I told him $100 is my maximum without knowing the battery specifications. He couldn't tell me anything, so they must be China specials. That generally means it's completely up in the air if the cells are real or counterfit inside. I was willing to try one at $100, but not any more than that.
The one I ended up with was $449 with 10S 42V/3A charger included out of California, so there was tax and $19 shipping too ($508 total - not cheap!). But, it has a known specification BMS and better quality Samsung 3200mAh cells that will handle 25A draw easily (my controllers maximum). The builds unknown amp draw and no known BMS were big issues for me on the little 8.55Ah one.
In the long run I bet I will be happy I spent up for some good range. I run a 48V 21Ah/1008Wh Panasonic-Sanyo GA 3200mAh battery pack on my BBS02-B 750W ride and can pull over a 100 miles range out of it if I don't speed and pedal consistently; it yields a very reliable 60-70 mile range the way I typically ride it (6'2" 230lb. Clyde here).
Having that extra 7.5Ah's for only 2.5lbs. more weight, the BMS and plenty of amp draw ability without much heat generation will be nice.
Those small 8.5 ah packs do appear to have a BMS clearly pictured in the seller's ad showing the internals of the pack but I sensed from the wording of the ad and description they knew very little about the product. I purchased the first one because I needed a small 36v pack to test a couple project bikes and was pleasantly suprised that the pack is actually in a nice plastic hard sided enclosure and it's been giving me good range riding across town and back up the steep hills to my home but I don't want to push a small pack like that hard. The case it's in is nice enough that I don't want to crack it open to look inside.
If this was my only battery I'd do what you did and opt for something with some decent range, it'll be a whole lot easier on the battery if you plan to do any real riding of any distance.