Max Peak Amp Draw for Lithium on Navitas System
 

I have a 2015 EZGO Shuttle 6 with a complete Navitas system, including the motor. I have Lead Acid in it now but want to replace it with lithium. My question is, how many peak amps do I need with Lithium batteries? I've been looking at capacity of around 100AH, with 100A discharge and peak discharge of 200A. Is that enough or do I need more?


- Dave

Re: Max Peak Amp Draw for Lithium on Navitas System
 

Peak of 200 is very marginal for a high performance cart. My cart pulls 300 amps under acceleration. It cruises at about 70 amps at 24mph.

Re: Max Peak Amp Draw for Lithium on Navitas System
 

Oh wow, do you know of any lithium that even hits 300??? Even the Patriot ones barely do that.

Re: Max Peak Amp Draw for Lithium on Navitas System
 

My Leaf cells do it just fine. Almost 5 years and counting on my first install.

Re: Max Peak Amp Draw for Lithium on Navitas System
 

Leaf? Is that the brand name of them?

Re: Max Peak Amp Draw for Lithium on Navitas System
 

Nissan Leaf repurposed (used) cells. A lot of info on here about using these cells in your cart.

Re: Max Peak Amp Draw for Lithium on Navitas System
 

EV cells have much higher current capability than most of the drop in solutions. The down side is that they are harder to get as they come out of salvaged cars. Leaf cells work very well and are easy to configure for a 48V cart. If you use 14 modules (each is two series cells) in a series/parallel config you get plenty of current capability and decent range. Whole pack weighs 110 pounds.

Re: Max Peak Amp Draw for Lithium on Navitas System
 

My card is almost exactly the same. I pull up to 300 amps on max acceleration from a dead stop. Cruising at 24 requires around 70 amps.

The issue with the limited discharge current is normally the BMS, not the cells. I have cells out of a Chevy Volt and am quite happy. Leaf cells are easier to work with but I picked up the Volt cells at a good price. 3 years and counting. I would be looking at a dying lead acid pack by now in the Florida heat so I'm glad I went lithium.

Also there are many other lithium cells available on the market now. It used to be Leaf or Volt and that was it. Now you can get cells from every major auto manufacturer.

Re: Max Peak Amp Draw for Lithium on Navitas System
 

You are correct in that with NMC cells the limiting factor is usually the BMS but the LiFePO4 cells that the drop-ins use are usually only rated at 1C continuous and 2C or if you're lucky, 3C maximum. So a 100Ah LiFePO4 cell will only be be to provide 100A continuous and 200A to 300A max. You can, at a minimum, tripple those numbers for a comparable NMC cell.

Re: Max Peak Amp Draw for Lithium on Navitas System
 

Not sure that the LiFePO4 cells used are really made for traction motor applications where as the NMC cells come from that application. Carts are much less punishing on the batteries than the cars they came out of. But currents are very similar. Nissan Leaf has 48 modules (older versions that my cells came from) all in series which gives nearly 400 volts. I am running modules in series / parallel so each module only sees half of the current.