# Lithium battery issue **URL:** \ **Category:** GEM Forum\ **Tags:** batteries, lithium\ **Created:** [April 13, 2025, 3:39am UTC](https://community.electricforum.com/t/lithium-battery-issue/29083 "2025-04-13T03:39:23Z")\ **Posts on this page:** 3\ **Page:** 1
**Author:** ![gkupsch](https://avatars.discourse-cdn.com/v4/letter/g/f08c70/32.png) [@gkupsch](https://community.electricforum.com/u/gkupsch)\ **Post date:** [April 13, 2025, 3:39am UTC](https://community.electricforum.com/t/lithium-battery-issue/29083/1 "2025-04-13T03:39:23Z")
2003 GEM, Ride4fun upgrades (T5, motor, gear set, tires/rims and electrical wiring) and 6 72v Allied 18ah lithium batteries (3 years old) with meter and shunt. Cart does 45+mph on level roadway. Need to pick everyone’s brains on this one. Drove 8 miles and rested cart for 2 1/2 hours. After 4 miles driving home, every thing shuts down including the battery meter which is directly connected to the batteries. Plug in cart to charge for a moment, unplug and batteries are showing 77 volts. Charged for 30 minutes then drove home the additional 4 miles with no issue. Plan is to run the car off each single battery at top speed to see if there’s any issues. Other thoughts? ---
**Author:** ![AssyRequired](https://yyz2.discourse-cdn.com/flex030/user_avatar/community.electricforum.com/assyrequired/32/7621_2.png) [@AssyRequired](https://community.electricforum.com/u/AssyRequired)\ **Post date:** [April 13, 2025, 7:39pm UTC](https://community.electricforum.com/t/lithium-battery-issue/29083/2 "2025-04-13T19:39:14Z")
It is the opinion of many that hang out in this group that multiple 72v batteries in parallel is a design that will eventually fail (72v in a 6P). I am very surprised that it took 3 years for you to run into the issue. Hopefully those Allied batteries all are monitored by their own internal BMS. Is sounds like one or more may have gone offline/left the chat. There is no way to tell which one it might be without unhooking and testing each battery to see if it still has an output. I doubt your car will work with only one battery hooked up at a time. It would be great if you had BT access so you could check condition of each battery while they are still configured. ---
**Author:** ![Inwo](https://yyz2.discourse-cdn.com/flex030/user_avatar/community.electricforum.com/inwo/32/1067_2.png) [@Inwo](https://community.electricforum.com/u/Inwo)\ **Post date:** [April 13, 2025, 8:13pm UTC](https://community.electricforum.com/t/lithium-battery-issue/29083/3 "2025-04-13T20:13:05Z")
> [@AssyRequired](#): > > multiple 72v batteries in parallel is a design that will eventually fail I totally agree. You are seeing the biggest problem. There is no way to know how many batteries are pulling their weight. I suggest 6 ammeters, if you plan to keep these.