I'm purchasing a 72v 40ah lifepo4 battery. Question regarding the BMS

[Bhopson23]

Hello, I hope I'm posting this in the right forum. I recently bought a used Armada Preditor 72v ebike. The battery pack that came with it is a 72v 32ah SLA battery, and it is either at the end of its life cycle or was not taken care of, because it dies within 30 mins of driving it. I'm in the process of purchasing a new 72v 40ah lifepo4 battery pack. It costs alot of money so I wanted to double check a few things. The controller is rated at 40A with a peak of 80A. My question is regarding the amp hours between the battery and controller...Should the battery match what my controller is rated for. Or should it be higher than the controller. I will post a link to my bikes specs. As well as the battery im purchasing. And I really don't know alot so im just learning as I go so I appreciate everyone's help.

http://armadascooters.com/product/armada-predator-electric-moto-72v-500w-high-torque/

https://www.lifepo4battery-factory.com/product/72v-ebike-battery/

 

[e-beach]

Your battery, bms and controller should all match in that they don't over charge and over discharge your battery.

As for your question about the controller drawing 80 amps, the specs you posted state that the battery can handle a 20C discharge. That would be 800 amps. That sounds high from where I am sitting, but if you are pulling 2C (aka 2 times the battery amp rating, or 80amps) that would be well within the specs you linked.

 

[john61ct]

The controller is rated at 40A with a peak of 80A. My question is regarding the amp hours between the battery and controller...Should the battery match what my controller is rated for. Or should it be higher than the controller.

Ah is the quantity of energy, like gallons.

Amps is the flow rate, voltage like water pressure

Power is Watts, amps * voltage.

Controller determines the amp rate, battery needs to be able to supply the power level, what it wants

Ah determines range, but also bigger capacity can supply higher peak power.

C-rate is amps output compared to Ah capacity so a 50 Ah battery supplying 100A rate is 2C, can only last 20-25min

 

[Bhopson23]

Yah I'm sorry I should not have posted the battery specs because I had already told them to change it ..

 

[Bhopson23]

This is my controller. So this would all work together?

 

[goatman]

have you disconnected the 32km/h speed limit wire?

that battery will probably be fine but it doesnt look serviceable

if you live in New Westminster or Nvan where there is alot of steep hills you might have issues

your controller is rated for 3000 watts, thats 72v 40amps

 

[Bhopson23]

Hey thanks for the reply. Yes I bought it with the limiter already disabled I use a gps app on my phone for my speedometer because my bike won't display higher than 32. I live in Victoria on the island

What do you mean by it doesn't look serviceable

The reason I'm buying such a large battery is I want to be able to get as much distance as I can out of it. I'm more worried about distance than I am power

 

[goatman]

some batteries you can open up

if your bms dies, you can open the case and replace it instead of having a very expensive door stop

these are 12v but serviceable

https://www.youtube.com/watch?v=RxMIs0PXrBw

 

[monette999]

I have ordered an similar 3Phase Controller. Can you share your experience with this controller

Greetings Bob

Gesendet von meinem CPH1911 mit Tapatalk

 

[999zip999]

Before you spend your money for that battery how much is it and exactly which one has you have you settled on ? As there could be better batteries out there for the money. It's better to have an over spect battery more empty hours and more usable amps or wattage out of it. Because the battery just sits there the controller demands from the battery through the throttle. Aka controller. The battery will run to it dies through the BMS or for other reasons it is dumb.