Anyone doing Regen with Lithium?

[Gregorio]

Curious to see if anyone is worried about over voltage and how to control it.

[Cruise Master]

That's a fantastic question and thinking beyond just the basics.

Does make a person pause and think about the amount of heat that could be generated during that regen phase.

ScottyB with his temp sensor sure would be nice to have on something like this to see if logic and reality do go hand in hand.

[Gregorio]

I have both a volt meter and an inductive ammeter on my cart. I can see the voltage go up as soon as regen kicks in, which, BTW is more often than I expected. I'm going to drive it a few days more and then check cell equalization.

As for heat, I'm stopping after going up and down some really steep hills to check with a laser thermometer. So far the only part of the system that has been a few more degrees over ambient are the Field terminals at the motor. They were 15F over. Every part of the battery is ambient.

[Sergio]

It should be fine, lithium batteries can take almost the same discharge current as they take charging.

The constant current / constant voltage is more related to the finishing charge profile.

Make sure the Alltrax is set to proper max voltage for your pack and the Controller will keep Regen below that.

My standard Lead Acid goes up to 60v at the bottom of hill near my home and I think it was about 80 amps when I measured.

[Gregorio]

Originally Posted by Sergio

It should be fine, lithium batteries can take almost the same discharge current as they take charging.

The constant current / constant voltage is more related to the finishing charge profile.

Make sure the Alltrax is set to proper max voltage for your pack and the Controller will keep Regen below that.

My standard Lead Acid goes up to 60v at the bottom of hill near my home and I think it was about 80 amps when I measured.

I am thinking it will be fine as well. After all, more amps are coming out than going in. Still waiting for Alltrax to get back to me on the implications of the High Voltage setting. Not sure if it will shut everything down or just regen. If the former, does it happen gracefully or is it like flipping a switch? If the latter, I could possibly live with that by lowering my full charge voltage a bit and set the Alltrax at the pack maximum.

[Sergio]

I would be curious to know the answer direct from the source as well, I would hope the Controller reduces/eliminates the Regen current to keep the battery voltage below the max setting.

[PingEye3]

I have done five lithium conversions using the XCT. I have reset all of them to 59V, just over the pack max of 58.8, which is as sergio suggested above. No issues with any of them.

[Gregorio]

Originally Posted by PingEye3

I have done five lithium conversions using the XCT. I have reset all of them to 59V, just over the pack max of 58.8, which is as sergio suggested above. No issues with any of them.

I was hoping you would chime in. Do you have any advice for the regen rate settings? I really have no idea what they do and the instruction manual is not clear other than to say it is critical for Lithium.

[PingEye3]

I adjusted regen for the braking feel that the customers wanted. I never worried about high voltage. On my cart with the Executioner, there is no regen, which makes my disc brakes even more necessary.

[PingEye3]

On the XCT 48400, I think I remember the regen setting at around 200, typically.