niallbeggan
1 µW
- Joined
- Jan 1, 2017
- Messages
- 2
I'm building my first electric bike, and am unsure where to get a good BMS that can balance my battery, (36V 10s4p 18650). Any recommendations?
What BMS
- Thread starter niallbeggan
- Start date
There are many threads about various BMS types, if you look around for threads with BMS in the title. The discussions may help you understand the differences between different kinds, terminology, and what you need to know about your system and battery to pick the right one.
If all you need is one that balances your cells, but has no protections, you may be best served with a set of RC chargers that can charge sections of your pack independently.
If you need one with the ability to shut off the pack to protect it against overcharge and overdischarge, then you will need to know what the maximum current your system requires is, and get a BMS that can supply at least that much, preferably with some extra capability to spare, say, 20% more amps than you actually need (so you are not stressing it, and you have a little wiggle room in case you upgrade or modify your system later a little bit).
You shouldn't exceed teh capability of the actual cells you're using, however, so you'll want to look up their specs to find out what their limit is.
If all you need is one that balances your cells, but has no protections, you may be best served with a set of RC chargers that can charge sections of your pack independently.
If you need one with the ability to shut off the pack to protect it against overcharge and overdischarge, then you will need to know what the maximum current your system requires is, and get a BMS that can supply at least that much, preferably with some extra capability to spare, say, 20% more amps than you actually need (so you are not stressing it, and you have a little wiggle room in case you upgrade or modify your system later a little bit).
You shouldn't exceed teh capability of the actual cells you're using, however, so you'll want to look up their specs to find out what their limit is.
niallbeggan
1 µW
- Joined
- Jan 1, 2017
- Messages
- 2
Hi amberwolf,
thanks for the reply
I did look for BMS threads, but didnt find much discussing various BMS' mostly threads about why a specific one was broken.
I already bought a cheap charger on nkon with my cells, RC lipo chargers seemed like too much hassle. I bought a cheap hub motor kit on amazon, 36 volt 500 watt so I assumed max current is 14A.
The cells I picked were Samsung INR18650-29E 2900mAh E7. I just picked the best capacity/euro on nkon that still met my requirements. I made a mistake in the previous post, I meant to say a 10s5p pack, which would mean 2.8 Amps max per cell which should be fine?
I also need the ability to shut off the pack to protect it against overcharge and overdischarge, are most of the BMS available fixed at 4.2V and 3V limits? Is this the range most people use their batteries in, would 4V and 3.2V limits be too conservative?
do you think something like these would be ok?
https://www.ebay.co.uk/itm/322451815873
https://www.ebay.co.uk/itm/10s-36v-20A-Li-ion-Cell-Lithium-Battery-Protection-BMS-PCB-Board-w-Balance-el/323549299518?_trkparms=aid%3D222007%26algo%3DSIM.MBE%26ao%3D1%26asc%3D20160323102634%26meid%3D5ceb29640b6e43f8a56ca0cb5ce41baf%26pid%3D100623%26rk%3D3%26rkt%3D6%26sd%3D322451815873%26itm%3D323549299518&_trksid=p2047675.c100623.m-1
thanks for the reply
I did look for BMS threads, but didnt find much discussing various BMS' mostly threads about why a specific one was broken.
I already bought a cheap charger on nkon with my cells, RC lipo chargers seemed like too much hassle. I bought a cheap hub motor kit on amazon, 36 volt 500 watt so I assumed max current is 14A.
The cells I picked were Samsung INR18650-29E 2900mAh E7. I just picked the best capacity/euro on nkon that still met my requirements. I made a mistake in the previous post, I meant to say a 10s5p pack, which would mean 2.8 Amps max per cell which should be fine?
I also need the ability to shut off the pack to protect it against overcharge and overdischarge, are most of the BMS available fixed at 4.2V and 3V limits? Is this the range most people use their batteries in, would 4V and 3.2V limits be too conservative?
do you think something like these would be ok?
https://www.ebay.co.uk/itm/322451815873
https://www.ebay.co.uk/itm/10s-36v-20A-Li-ion-Cell-Lithium-Battery-Protection-BMS-PCB-Board-w-Balance-el/323549299518?_trkparms=aid%3D222007%26algo%3DSIM.MBE%26ao%3D1%26asc%3D20160323102634%26meid%3D5ceb29640b6e43f8a56ca0cb5ce41baf%26pid%3D100623%26rk%3D3%26rkt%3D6%26sd%3D322451815873%26itm%3D323549299518&_trksid=p2047675.c100623.m-1
