Roypow battery shutting down

[Pat911]

You may still be exceeding the 160A continuous limit for greater than 30 seconds.

Without having engineered the battery myself, but from their specs I assume…..
You can draw 0-160A indefinitely.
160-315A for 30 seconds.
Greater than 315A is instant shutdown.

[WC53]

Originally Posted by Pat911

Not exactly true. They run the current through the BMS because it’s simpler and creates a drop in solution. If they didn’t, then the carts wiring would have to be spliced into to disable the controller (key switch) on low voltage conditions and each carts wiring is different. A headache for the manufacturer.

I was meaning to have the bms control a contactor on the battery. Aka a Orion or batrium bms style.

[Beerdude77]

Originally Posted by Pat911

You may still be exceeding the 160A continuous limit for greater than 30 seconds.

Without having engineered the battery myself, but from their specs I assume…..
You can draw 0-160A indefinitely.
160-315A for 30 seconds.
Greater than 315A is instant shutdown.

Would it be possible to use the "On the fly" control panel on my dash to lower the current draw to prevent a shut down when I encounter steep hills? If so, the speed dial or the acceleration dial?

I saw it mentioned the 72v would help cut the current draw, what would the max indefinite limit be in that set up?

Thanks again for everyone's responses!

[Pat911]

With everything else being equal, same motor load, same hill, same cart weight etc. the Navitas AC system will draw 2/3 of the current when running from 72v as opposed to 48v.

So if you were drawing 200A on that hill at 48v, it would drop to 132A at 72v.

As for the on the fly programmer, I guess so, try it. Speed would be the one to try as you’ve got 30 seconds of higher current available for acceleration. It’s the steady state current draw when you’re at speed that seems to be your problem.

@WC53, yes, you’re correct. A contactor isn’t that expensive, relative to the battery cost but they still would need higher quality cells to supply the higher current.

Cheers
Pat.

[Beerdude77]

Originally Posted by Pat911

With everything else being equal, same motor load, same hill, same cart weight etc. the Navitas AC system will draw 2/3 of the current when running from 72v as opposed to 48v.

So if you were drawing 200A on that hill at 48v, it would drop to 132A at 72v.

As for the on the fly programmer, I guess so, try it. Speed would be the one to try as you’ve got 30 seconds of higher current available for acceleration. It’s the steady state current draw when you’re at speed that seems to be your problem.

@WC53, yes, you’re correct. A contactor isn’t that expensive, relative to the battery cost but they still would need higher quality cells to supply the higher current.

Cheers
Pat.

So based on this information I can't help but think the Extreme Team 72v/150ah battery with 350 peak and 300 continuous would be sufficient? They told me the top speed for this battery on flats would be in the 45-50mph range (no way I take this cart that fast, the 29-30 I was already getting was dangerous enough) So if that is the case I should be able to dial the top speed down to reduce current draw and prevent shut down, correct?

Thanks again

[Volt_Ampere]

You need to dial down the max current as well as max speed. Max current can be at very low speed if you are going up a hill and trying to accelerate fast. Higher design voltage will result in lower current with the same power output but you need more cells to get that higher voltage. The same can be achieved by paralleling cells which creates a battery that can handle higher current. Unfortunately, to keep cost more reasonable, most drop in solutions are marginal on current capability.

[Pat911]

The Extreme Team 72v/150ah battery with 350 peak and 300 continuous would be equivalent to a 48v/225Ah, 525A peak and 450A continuous. Which is at least twice as powerful as the battery you removed. I don’t know your cart/current draw but If you believe those numbers are good, then go for it.

Cheers
Pat.

[Beerdude77]

Originally Posted by Pat911

The Extreme Team 72v/150ah battery with 350 peak and 300 continuous would be equivalent to a 48v/225Ah, 525A peak and 450A continuous. Which is at least twice as powerful as the battery you removed. I don’t know your cart/current draw but If you believe those numbers are good, then go for it.

Cheers
Pat.

I am not sure of the current draw in this situation either. It really sounds like it will do the job but I want to confirm before buying. I reached out to ET to see what they say, I will report back once I hear from them.

[ousuxndallas]

Wow, good topic. I'll piggyback on this if the OP doesn't mind. I have a 48v Precedent with a 400amp Alltrax controller, and offroad tires. Use it for deer hunting.

My batteries are about to give out, and I'm thinking of switching to lithium. Would a 100ah 48 volt drop in be good enough for hills, mud, etc?

[Pat911]

Hi,

It’s not about the Ah rating, it’s about the continuous and peak currents the battery is able to supply.

Your cart looks like it will need substantial current to get it going, especially with hills and mud. You would probably need at least something like the OP initially had, 160A continuous with 315A peak.

Since you have an Alltrax controller, can you log the current draw, that will tell you exactly the type of battery you need.

Cheers
Pat.