New batteries quick discharge

[Unsoshl]

Good morning all. My brother bought new blackbox trojan 8v's for his 2011 ydre. While charging, the batteries read 55-56 volts which I believe is normal. However, after unplugged for 12 hours the pack read 50.01 yesterday. He took a 30 second spin, and the pack had dropped to 49 volts. I previously unhooked the voltage reducer in case it was drawing. The cart is otherwise stock. Any thoughts? Thanks!!

[scottyb]

55 is hardly a full charge and 50.9 is normally what you want to see from a 48v pack at rest.
You may need a better charger?

[Unsoshl]

Thanks Scottyb. His charger appears to operate and shut off as normal, but I’ll try mine out to see if that’s the issue. Appreciate it!!

[Unsoshl]

So I used my charger on his cart, and after charger showed solid green (full charge) the cart was at 51.0 right when unplugged. I know this is low, but am at a loss as to why it isn’t fully charging.

[Sergio]

Make sure the charger receptacle positive lead is connected to the pack positive battery post so all batteries are charging.

[Unsoshl]

Just verified it is. If it helps, each battery is between 8.46-8.5 volts after charge.

[onewheelcop]

Originally Posted by Unsoshl

So I used my charger on his cart, and after charger showed solid green (full charge) the cart was at 51.0 right when unplugged. I know this is low, but am at a loss as to why it isn’t fully charging.

51v is a full charge!!!! Actually 49.9v is 100%. I have a smart charger for mine and it usually reads 51-52v while plugged up and in maintenance mode. but unplugged it falls to 50.9-51v

[Mooncarter]

Originally Posted by onewheelcop

51v is a full charge!!!! Actually 49.9v is 100%. I have a smart charger for mine and it usually reads 51-52v while plugged up and in maintenance mode. but unplugged it falls to 50.9-51v

49.9 is less than 80% charged. 51 would be a good reading after resting 12 hours. Charger should put out over 60 volts near end of charge.

[onewheelcop]

Originally Posted by Mooncarter

49.9 is less than 80% charged. 51 would be a good reading after resting 12 hours. Charger should put out over 60 volts near end of charge.

My bad..I meant 50.9v is a full charge.. I think different chargers will perform differently. My Accusense Smart Charger never gets anywhere close to 60v while charging. I have seen 54.5v at its highest. And once it gets closer to being fully charged it backs way off on voltage. this morning it is maintaining at 51.1v

[Unsoshl]

Anything else you folks suggest I check? Frustrating. I sure appreciate your help as always..