Does Ah equal discharge Amps for BMSs?

[GStar42]

Hi all,

First off, I apologise as I know this is a Solar forum not electronics forum, but this place seems like the best place to ask, as I’ve read quite a few threads here about building diy LIFEPO4 batteries.

So I’m currently building a battery to power a robot that is powered by two electric motors with a combined wattage of 500w (rated). I plan to power off 8s, and want about an hour’s (ish) worth of run time. Each motor’s individual rated current is about 12a (2x12a=24a) so I’m looking at a 8s5p configuration (24v 30ah, as I’m using 6000mah cells). Do I need a 30a bms or should I go a little higher to account for the max power of the motors which is a combined 900w or so (max current around 20a)? If so, how do I account for cell balancing for an 8s5p configuration on a bms with a higher amp rating than 30a (as in, will there be extra leads, and if so, how do I wire them up properly?)

Again, I understand this is a little off-topic for the forum, so my apologies, but as I said earlier, I’m hoping someone with a little more experience might be able to explain this?

For reference, I have previously built li ion battery packs but these have high c ratings and the bmss reflected that higher amp output.

Thanks!

 

[MisterSandals]

two electric motors with a combined wattage of 500w (rated). I plan to power off 8s, and want about an hour’s (ish) worth of run time. Each motor’s individual rated current is about 12a (2x12a=24a)

250W per motor / 12A = 20.8V ?

24v 30ah

30Ah x 24V = 720Wh battery capacity

720Wh / (250W x 2 motors) = 1.44h runtime

Get a BMS about double your expected amp draw (50A-100A)

 

[zanydroid]

I don't have the knowledge to help, but note r/batteries has expertise, as does Endless Sphere. You might also check RC forums.

r/batteries has some smart people, but mixed in with a few low effort reddit posts.