2002 ezgo lithium conversion ISSUES!!

[Bass assassin]

My friend has a 2002 ezgo, I will attach a pic of info plate. We converted it to 36 volt 27AH Ionic lithium batteries, wired parallel. Everything was great and then it just stopped...ended up replacing the computer, and everything worked again. But now after a 5 to 10 min ride, it just stops working. The computer, motor and cables are all hot when this happens. After it's sits for a few minutes, it starts working again like nothing is wrong. I have 38.4 volts to everything that receives power. I should also mention, there is no governor, and it will deliver all the power. It drains the batteries way faster than it should, and will get up over 30 mph. Do I simply need an upgraded heavier duty cpu? What am I missing? We don't want to blow the new computer. Thanks to anyone and everyone.

[meimk]

I am by no means the final word on this, but that 27 AH pack seems WAY low. The common one I've used was the ECO 105 AH. I'm guessing that with that little power the voltage drops too low & the BMS and or controller shut down. Particularly if running 30 MPH. Also, it's common for amperage draw to go up as voltage drops. Trying to draw more amps will generally cause heat.

[Bass assassin]

Thanks for the response, we have 2, 36 volt 27AH batteries, so 54 AH? ....I of course didn't do any research before I started this, and I agree with you, I think I should have gotten higher AH rating....but I know several people who are running these exact batteries and most are running 2 batteries and some 3, and they don't have my issue....they don't have the same cart as us, but i was hoping for their success!

[jasonojordan]

Alot will depend on the BMS ratings used on these. I would think you would need a minimum of 2 to have success with having enough available amperage to not be tripping out the BMS all the time even on a stock cart. 3 would be alot safer in that regard for overhead.

[Volt_Ampere]

Your batteries are the weak link in a cart that has no power limits. I'm sure that the batteries are seeing too much current. A third battery would help. A controller that can limit the current would also help.

[Capt. Lenny]

Just out of curiosity, what brand of batteries are you using? And just a suggestion, if you don't have #2 gauge cables get some, they're always a worthwhile addition and will greatly help with a hot cable issue. Just like a straw you gotta get more of the available juice to the controller and motor.

[Volt_Ampere]

Show a picture of your install. One critical issue with parallel batteries is matching the cable impedance. Otherwise, the current doesn't split equally and one battery can be overloaded first - tripping it's BMS.

[DaveTM]

You stated “everything is hot”. Define “hot”. Hot to the point where you can’t touch it? If that’s the case, your cables may be undersized and/or the connection ends may be rusted or corroded.

Heat indicates poor connection. If it’s hot to the touch, you’re losing too much energy.

As to the amp-hr, 27 seems far to little for a cart. I’m not surprised that you get short run’s with the low amp-hr and the energy loss via heat.

[Volt_Ampere]

He has two in parallel which is 54 AH. Still marginal but should be functional.

[DaveTM]