Battery compatibility

[E-StreetBikes]

Hey guys i just bought 3 batteries for a 3000w 80A kit. Im building 3 bikes from scratch. This whole time the guys i get my kits from have been selling me 80bms batteries. Ive built quite a few bikes already with an 80bms 72v battery and i have a new battery connect and they are telling me this will not work. i need a battery with a continuous current if 80 amps is this true? The 80bms seems like its been working fine. i also learned that the continuous current is usualy half the bms. The bike will rarely ever hit a full 80amps the average is around 60amps what do you guys think? 80a continuous current/ 160bms is very expensive and is being that extreme necessary? could i go with a 60a continuous current sense 60a for this kit is the norm? very rarely will it go higher than 60a plus the 60a continuous battery has a max current of 120a. i need advice i want to do the right thing.

 

[E-HP]

What is an "80bms battery"? Do you have a link?

 

[E-StreetBikes]

I dont have a link i get the. on alibaba. i couldnt find a link for that exact battery even if i tryed. 80bms means it will shut down the battery once it hits 80amps

 

[Jonno]

Just bypass the bms negative side.
Battery + direct to controller
Battery - direct to controller

Charge + to battery +
Charge - to bms C-

This will allow this cells to balance charge and balance at rest but the discharge will be the battery maximum continuous amps and burst amps without overloading the bms

Hope this helps

Jonno

 

[HK12K]

Wait wait wait wait wait.

Don't buy batteries from Alibaba.

 

[E-StreetBikes]

where else should i get them? Especially at whole sale price.

 

[HK12K]

For turnkey packs at reasonable prices from overseas, em3ev is one of the few I would trust. Unless you can find a local builder who does quality work at reasonable rates.

 

[Eastwood]

where else should i get them? Especially at whole sale price.

How much are you looking to pay for a battery? You mentioned wholesale but those websites call everything wholesale lol

 

[E-StreetBikes]

Im looking to pay around $300 for 72v 80bms 25AH. thats a common seller for me. ive been getting them from this failry large company in china thats been in business for over 10 years. it took my a while to find some one who seemed as reliable as them but so far so good. they seem to know what their talking about and they have good reviews. if i cant find reviews on aome one or any kind of information i wont buy from them.

 

[999zip999]

Do you have a link

 

[E-HP]

 

[Chalo]

Im looking to pay around $300 for 72v 80bms 25AH. thats a common seller for me.

First of all, don't do that.

Second of all, if you do that, please keep in mind that all the ratings and specifications will be outright lies.

 

[LewTwo]

Im looking to pay around $300 for 72v 80bms 25AH. thats a common seller for me.

First of all, don't do that.

Second of all, if you do that, please keep in mind that all the ratings and specifications will be outright lies.

and that you can NOT return it.

 

[HK12K]

Not to mention that you will have no recourse when it causes injury to one of your customers or their home when it spontaneously goes up in flames. It will all fall on your shoulders as the retailer. Fair warning. You are playing with literal fire.

 

[E-StreetBikes]

Do you have a recommendation then? Id rather play it safe. Ive been getting batteries from NB power for my high powered kits and they seem to be working fine. ive been using them for a while.

 

[E-HP]

Do you have a recommendation then? Id rather play it safe. Ive been getting batteries from NB power for my high powered kits and they seem to be working fine. ive been using them for a while.

If you trust your source, then just get the battery from them. Remember that the purpose of the BMS is to protect the battery, so no matter what kit you have, the BMS should be sized so the battery can provide up to it's rated output. I realize different BMS' may function differently, so your mileage may vary, but the couple that examples I've used can deliver more than the BMS continuous rating without tripping. One is rated at 30A, and I could regularly pull 40A+ without tripping. I could trip it from a stop with full throttle though, if the controller wasn't set to limit the current. The one with a 40A BMS has provided 110A in a short burst without tripping. I might be able to trip it if I jammed on the rear brake with WOT, but not interested in trying.

As long as the cells in the 80A pack can actually provide at least 80A continuous, I'm guessing the 80A BMS will work, unless you pull a lot more than that continuously. Why not try one of your existing batteries on the new setup to see?

BTW - 3000W at 72V is 41A. 80A would be 5.76kW, so not sure you want to run the motor above that level continuously anyway.

 

[E-StreetBikes]

haha ya no need to run it that high for that long around 40a continuous is the norm. probably peak around 70a some times but ok thanks man that makes sense. that what i thaught but i want to be 100% sure thank you for the advice!