2017 RXV Issue with New Lithium upgrade

[Cwad8505]

Originally Posted by jjordan32875

Hi all...new to this forum but been reading a lot on lithium conversions for an RXV. Could someone recommend a lithium solution that actually does work when converting from lead acid? I can't seem to find a lithium battery that allows for enough peak amperage draw for an RXV based on what I've read on the forum. My cart is in an area with steep hills and therefore assume I would be demanding max amp draw often. Should I stay with lead acid or is there a lithium pack that works without complicated modifications? I have a 2018 RXV with 6" lift. Everything else is stock. Thank you!

Knowing what I know now, I would have selected the 48v HSKY kit from bigbattery.com. 58v battery that should accommodate the voltage produced on regen and hard braking.

[rajames17@gmail.com]

Originally Posted by PingEye3

There is no brake solenoid on an RXV. Main solenoid only. When I first read 'slammed on brakes' I thought you meant the battery tripped and with all power turned off. The brakes will lock up in that scenario, as designed. But, I think you are saying that YOU slammed on the brakes. If so, the brakes worked like they are supposed to. When stomping the brake pedal, for a panic stop, once the brake limit switch activates with full pedal travel, they will lock up. Most people driving the RXV rarely use the brake pedal as the brakes are regen only to stop the cart under normal driving. Unless slamming the brakes, when they lock up. Regen can be adjusted with the handheld programmer., but it cannot be disabled as that is your only braking system on an RXV. You cannot adjust regen to a current or voltage value. You are adjusting it for brake feel only, ie, how much braking you feel when letting off throttle.

If you are saying the cart, while driving at full throttle and fully charged, then it locked up when you let off the pedal. Then it is possible that the BMS shut off the pack due to high regen voltage while braking. If it tripped the main contactor because of that, your brakes would have locked up. You can make regen adjustments to soften the affect.

So we I’m having the issue you referring too. I have a 2008 RXV I upgraded to lithium and I’ll be driving let off the gas or touch the brakes and it locks up. I have to turn it off, and back to forward or reverse to make it go again. It worked fine for a few months now does almost daily. What can fix it?

[Pat911]

The bigbattery.com BDGR is not a typical 48v nominal battery. It is NMC chemistry, which is not the problem, but a nominal 48v NMC battery uses 14 cells in series for a maximum charge voltage of 58.8v. The BDGR uses only 12 cells in series dropping the maximum charge voltage to 50.4v. A nominal 48v NMC battery should be 14 cells, not 12.

I can’t be certain without further info but what I believe is happening is what PingEye3 said, your motor/controller is producing too high a voltage during regen braking and the battery’s BMS does what it’s supposed to do and protects the battery by shutting it down. When the battery shuts down your ebrake looses power and locks up.

Do you find that this occurs more when the battery is close to fully charged?

Cheers
Pat.

[Glennie]

OK, I have a 2017 EZGO 48V RXV in which I want to install Lithium batteries. What brands have issues with the Regen brakes and which brands do not? How can I avoid the problems mentioned here? I don't want to have to do it over

[sleeplesstwo]

There are many good batteries that can handle the RXV, but I have had excellent success with the Epoch. The smallest I would recommend would be the 90ah kit. They have been working perfectly.

The Eco battery is now a site sponsor, as I understand, and many here are enjoying great success with their units as well.

Either of those options will give you trouble free use on an RXV.

[suzook]

Originally Posted by Glennie

OK, I have a 2017 EZGO 48V RXV in which I want to install Lithium batteries. What brands have issues with the Regen brakes and which brands do not? How can I avoid the problems mentioned here? I don't want to have to do it over

I have the roypow 105ah kit in mine. No issues so far.

[TheCartBoy]

Originally Posted by Glennie

OK, I have a 2017 EZGO 48V RXV in which I want to install Lithium batteries. What brands have issues with the Regen brakes and which brands do not? How can I avoid the problems mentioned here? I don't want to have to do it over

Just retune the controller for your lithium battery specs. This is what OP was missing.

https://www.buggiesgonewild.com/showthread.php?t=194038