2015 ezgo rxv high speed lockup problem

[atcrick]

New to the forum: 2015 ezgo rxv
e power 48V lithium upgrade a year ago, rest stock.

the story begins, day before event I ran the cart to about 10% left on battery,
charged all night, get in cart, I think cart was fully charged but not 100% sure. as I do not recall looking at the light.
drove 10 min, full speed lockup, battery showed 10% or less left on charge, could not get tow switch to unlock brake.
so...on my battery pack there is a on off switch...i turned off and then back on and the cart functioned normally for 30 seconds. then would lock up again.
I was 3 miles from home so... rinse and repeat . turn off/ on. drive 30 sec. lockup. repeat for 3 miles til home.

now will not take a charge, red charging light is on when plugged in, blue light flashes like charging but no,
so leave plugged in..turn off battery's.. turn on the battery's.. and i can hear charger start, then after 10 seconds stop..


I have ordered a new brake, key, solenoid in hopes of resolving the issue, due in a few days, I will see if if resolves the issue.

any thoughts from you guys?

[atcrick]

oh and by the way I dont think the battery's are dead, I was able to drive 25 MPH in between the 30 sec, that it was running.

[rabbitreborn]

Is this a RoyPow battery pack?

[atcrick]

no
elitepowersolutions
e power 4803E

[cgtech]

That's the danger of the lithiums that just abruptly "shut off" when they are low. Every time this happens, your motor controller is at risk of corruption/damage that may not be repairable. And the motor brake is taking severe abuse every time it locks up while underway. All the packs I've built just interrupted the throttle signal when the pack was too low, instead of abruptly shutting off, that way you would just roll to a stop, not lock up.

[atcrick]

thats what i feared happened, I will have to look for your fix when i upgrade the system,
probably time for the plum quick extreme motor with the Navitas TAC 2.0 600amp AC motor controller.

but i will play around with this thing a little longer

[cgtech]

Originally Posted by atcrick

thats what i feared happened, I will have to look for your fix when i upgrade the system,
probably time for the plum quick extreme motor with the Navitas TAC 2.0 600amp AC motor controller.

but i will play around with this thing a little longer

Nope, I was assembling my own packs & building BMS specifically for those packs. Since your pack has a built-in BMS, your stuck with that BMS. Maybe Elite has a solution, but I wouldnt hold my breath.

[rabbitreborn]

Originally Posted by atcrick

no
elitepowersolutions
e power 4803E

I'm not familiar with this battery but after looking them up I noticed it is a 60aH pack which would concern me somewhat.

I can say I had a similar issue with a RoyPow pack (not in a RXV) and what we found was one of the ribbon cables inside had come loose. The cart had power but as soon as a load was applied, it would shut down the pack. When we ran diagnostics on the pack, it was reporting a bad heat sensor on the pack, but was actually a partially un plugged ribbon cable going to the BMS.

[rabbitreborn]

Originally Posted by atcrick

thats what i feared happened, I will have to look for your fix when i upgrade the system,
probably time for the plum quick extreme motor with the Navitas TAC 2.0 600amp AC motor controller.

but i will play around with this thing a little longer

Plum Quick Extreme motor is actually the Navitas AC motor designed for their AC conversion kit designed for a DC powered cart. It has no option for the motor brake that is standard on a RXV. I have not heard of any aftermarket motors for a RXV that still incorporates the motor brake.

[cgtech]

So, how does it sit still, the motor brake's only normal job is holding a parked car still. Rxv has no traditional brakes, and no locking brake pedal. I've never seen/heard of any upgrade motors for rxv whatsoever.