Voltage Drop while Driving

[nobodeuno]

Hi Guys,

I have a 2008 Club Car Precedent with a 400amp controller installed and just converted to 8v -48v us battery pack.

I recently installed a cheap battery gauge I purchased off Amazon (digital) and when I drive it it drops with throttle down to 0%. I have it setup for a 48v pack and ran a small wire to the pack plus and minus. Curious why it would be reading like this. I could understand a small drop but this seems rather large.

Thoughts?

Also after installing the meter and letting the cart sit unplugged for a day it dropped 10%. Is this normal?

I still have the stock motor right now but considering upgrading that because I have a lot of steep hills in my neighborhood and it seems to really drag up hill. Like to a 5mph crawl sometimes especially without a fresh charge. I only mention that in case it is another symptom.

Thanks

Justin

[Fairtax4me]

If its one that shows a bar graph or the goofy Pie wedge graph, just chuck it in the trash because they're basically useless.

You have a brand new pack, how many times has it been charged? A brand new pack wont hold its full capacity until it gets about 15-20 cycles on it. It doesn't need to be babied, but you do need to limit how much you use the cart for the first few charges until the pack starts to break in.

What charger are you using? This is important, especially with higher quality batteries, that the charger is able to correctly charge them.

[nobodeuno]

This is the gauge that I purchased.
https://www.amazon.com/gp/aw/d/B07KS...b_b_asin_title

Is there another one I should purchase? A couple times my kids haven’t pushed the charge plug in all the way and looking for a way they can easily see the charge level.

I have a summit II charger and I have charged the battery about 5 times but probably only drained it 50% except one time my kid drained the battery fully and didn’t realize it. Hopefully that didn’t damage the batteries too much.

Thanks!

[CP241]

I’ve got one of these (and an allied gauge but it’s inside the glove compartment). The digital voltage gauge works well and gives real time voltage readings so you know exactly what the pack is doing.

Waterproof Monitor DC 4.5-150V 12/24/36/48V Volt Battery Meter Voltage Tester Automative Electric Cars Gauge Golf Cart E-Bike Bicycle Motorcycle Small Digital Voltmeter 0.56"LED Blue https://www.amazon.com/dp/B00NZV7K3G...HK5B8RF1RQF03E

Look up a state of charge chart (there’s several on this site). The voltage on that chart reflects after you drive it, park it, and let it rest 10 minutes or so.

Watch the resting voltage (compared to the SOC chart) and that’s way more accurate than the bar meters.

It will fluctuate under load while you drive it too. Everybody’s cart is slightly different depending on mods. The more you upgrade it, the more the voltage will dip under load (accelerating or going up a hill).

But depending on how you drive, terrain, mods, etc. you’ll just have to watch it to see what’s “normal” and you’ll be able to gauge your remaining battery life just based on experience.