Hi! I change my BMS configuration to charge only and I start having the problem that 2-3 cell packs are not balanced anymore https://www.electric-skateboard.builders/t/battery-doesnt-fully-charge-anymore/59812/49?u=rey8801. I would like to manually balance them every 3 weeks so do you have a good BMS advice? It can be discharge/charging or charging only. For discharge I need at least 60A, but I would like to avoid the problem I had with the BMS turnoff the board durign hard braking, when battery close to fully charge state. In the other thread @bartroosen12 suggested me this one https://www.aliexpress.com/item/32827750823/32827750823.html?shortkey=fmQRjeYJ&addresstype=600 which I like the fact that I can see real time values and be sure it’s working properly. I haven’t look deep in BMS world recently, is there something worth it at the moment? My limitations are size, max like 100x70x20 mm (already rather big I would say), the balance port, since mine is using the standard one and I would like not to open up all the battery and resolder the balance wires (Current BMS https://www.aliexpress.com/item/10S-60A-bms-Li-ion-large-high-current-BMS-PCM-with-SAME-discharge-port-for-electric/32829800932.html?spm=a2g0s.9042318.104.22.168424c4doLEYok). Thx guys!
@thisguyhere might have some charge only 10s bms. I use his 12s one and it works fine.
Thx, only thing I see that for the 10s the balance port is split it so I would need to resolder everything . But thank you for the advice, I know Bestech is a good one.
i havent used it yet but i bought a 10s bms from Alien Power Systems. i think it is a bestech and it has a built-in e-switch
i will have a look, although I do not need the switch anymore.
you dont have to use it. it is just a feature that will save you from having to get an antispark
I know it, I was just thinking loud
yeah bestech have the 10 pin plug on them, it works alright. What i did in my enclosure is design a cable that had the bms connected to my 2 5s leads, but have my Voltmeter in parallel with the battery so you can see the individual voltage of each cell. I then wired these up to a small switch so that i could check them only when needed
Brilliant! Really nice
just a handy idea to save you opening the enclosure to check voltages
If you need 60A I should go for a 80 or 100A bms: http://s.aliexpress.com/Ar6z2mIF?fromSns=
I’m going to make a 2kW electric mountainbike and gonna use a 20S 100A smart bms, same seller. I really like the 10S 60A bms I got, it just works perfect. The esc only pulls max 20A so it’s very safe with the 60A bms. You can set a lot of setting via bluetooth so very handy.
I have a 10S4P 30Q right now and I haven’t ridden for a month because I got exams but It’s good to check if the bms uses power when my board it’s just laying on my desk.
Inhave charged it to 41.5V, each cell perfect 4.15V and right now every cell is 4.1V so only used 0.5V in total for doing nothing so that’s fine. (I have set balance to always and the voltage diffence is set to 0.005V so the bms is almost always balancing to get every cell the same ±0.005V but I’m gonna set that value back to 0.01V it was just to test)
Hi! Yes up to now the one you have is my first choice. I have a 10s3p 30Q so 60A constant it’s still ok I think. With the new hubs i am using now I pulled out 52A at most, so should be fine or do you think it is too close? Otherwise I go with the 80A to be sure. I am waiting the sales, they should start in 4 days on Ali. I bought my BMS from the same seller but it is the basic one and only charging doesn’t do the job very well unfortunately.
@JLabs has Bestech bms’s in stock at bargain prices.
Yeh but I am in EU. Probably the shipping will kill the deal. I will check it.
Shipping should be around $15 for slow but tracked… if it isisnt let me know and i will have to fiddle with it to get it right
If a BMS that’s charge only isn’t working for you, and you still want to bypass for discharge, then a balance board is probably your best option. Something like This would work fine for your use.
It does not have any of the safety measures of a BMS, but you would already be losing all of that by bypassing it for discharge. The only difference between a balance board like this and a bypassed BMS is that the BMS will protect from overcharging from your charger (this excludes brake regen, that is unprotected still)
It’s a lot cheaper and a lot smaller than bypassing a BMS. It also will continually balance your cells, whether charging, discharging, or if your board is off.
I didnt’ know about it. I would only need to connect the balance leads to it. Right? So basically it does balance the cell continuously without the other feature of a BMS, which actually I do not use it anyway. Did I understand correctly?
Yep, no additional BMS needed. The page says you need one, but electrically there is no difference, the board cannot tell if there is a BMS there or not.
Thank you if I won’t buy a discharge BMS I will then go for it. ONe question in the diagram it says to connect B+ and B-, since it-s only for balancing two thinner wires is gonan be fine right? the same I use for the balance leads.