Installed new batteries and lost 5mph.. Help!

JakeJones8

Hey everyone!

Finally replaced my 7-year-old trojan batteries with brand spanking new US Batteries in March. Unfortunately, my cart was going 32mph with the 7-year-old trojans and now only does 27 with the US Batteries. Looking for some help, all ideas welcome!

I started with the batteries. I am probably 25+ cycles into the manufacture process of driving them down to 75% and immediately recharging. I have seen ZERO performance or range increase along the process (chart below of the first 12 charges). Because the cart voltage at rest was showing ok I decided to try each battery under load. I was able to find one that was much lower than the rest. Could that be the reason for 5mph loss??? I am trying to work with who I bought them from to get it replaced.

Graphs Below:

Screen Shot 2019-05-05 at 3.24.18 PM.png

Screen Shot 2019-05-05 at 3.24.29 PM.png

BGW

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Mooncarter

Looks like you have a bad battery.

ThreeCW

Battery 4 looks a little weak.

What are the fully charged stabilized individual battery voltages (at 24 hours after disconnecting your charger)? It would be interesting to see if Battery 4 is also weak after a full charge.

You report 50.9 v fully charged for every charge cycle. Is this an actual meter reading or an assumption based on being “fully charged”. My 8 pieces of 6v Trojans have a fully charged reading of 52.0 v at 24 hours after charging. My previous pack of US Batteries at 5 years old were about 51.5 volts fully charged. Maybe it’s the difference in using 4 x 12 v vs 8 x 6 v batteries. The point I am making is, are you sure you are getting a full charge.

Do you have a 48 v to 12 v converter? Or are any 12 v loads hooked up to your Battery 4 directly?

To fully trouble shoot you may want to take the specific gravity readings (after a full charge) of each battery cell and compare them. You might have a weak cell jump out at you. Start with Battery 4.

JakeJones8

Thanks for the response! To answer your questions:
1) Cart finished charging 12 hours ago and they are currently sitting at:
----->1-12.82v
----->2-12.83v
----->3-12.89v
----->4-12.79v
2) The 50.9 was just used for math purposes and showing it was fully charged. After sitting off the charger for 12 hours they are currently 51.2v
3) I have a 48 to 12 converter. Nothing is hooked to a battery directly.
4) I am not sure how to take a gravity reading but I am sure Google will help me out with that one, I'll do some research. Thanks!

JakeJones8

Bump. Any other options or things to test??

rib33024

The US batteries have a higher SOC than other batteries.


Most batteries. SOC










US batteries SOC