Battery info

[JohnnieB]

Originally Posted by Captain Claptrap

What if you did 2 banks of 3 12's so essentially you have them in parallel. Would that make it a wash and restore the trip capacity of the original 6 in series? Any drawbacks to such a config?

Typically, a 12V cart battery stores 150AH, so a 3S2P pack would be 36V-300AH, or 10.8kWh of storage.
The standard 6V battery used in a 36V pack is 225AH, or 8.1kWh.

Mathematically, that is about 1/3 more storage capacity, which indicates the range and lifespan is roughly 33% longer than 6x6V-225AH pack.

The numbers indicate the 3S2P 12V configuration would more than restore the trip capacity of the original 6x6V pack, but it would weigh about 120 pounds more, so the cart will perform like there is always an extra passenger onboard.

The existing 36V charger will probably work okay.

Keeping them all in balance might be an issue. I'd charge each individually with a 12V charger and pick those with the closest at-rest to make the parallel pair.


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IIRC, someone did this a few years ago, but I don't remember who, or if it worked out okay.

[Derek Diggler]

2008 Ezgo RXV - I live in Delaware and store my golf cart in my attached garage. What is the proper way to store over the winter? I don’t see riding it too much when it gets below 50 degrees. Should I just throw a charge on it once every couple weeks? Do I need to disconnect anything? Just bought it a month and a half ago and it has 4 12v Trojan batteries that are only 1.5 year old, so I want to take care of them. Thanks for your time.

[JohnnieB]

Every two week will be okay, once a month may suffice.
Check the fluid level every month or so. (Add distilled water only and don't over fill)

The batteries typically self-discharge at about 1% per day and you don't want to let them drop below 70%.

[Derek Diggler]

JohnnieB -thanks. I will do that. So no need to disconnect anything at all right? Just do what you’ve said. I have been keeping up with the water levels I check them every couple weeks. Thanks again.

[JohnnieB]

Originally Posted by Derek Diggler

JohnnieB -thanks. I will do that. So no need to disconnect anything at all right? Just do what you’ve said. I have been keeping up with the water levels I check them every couple weeks. Thanks again.

Not that I know of, but I'm not an RXV guy, so google RXV storage for better info.

[Coreyw4023]

What are most people spending on 4 new 12V batterys? Got a quote of 750 for trojans

[JohnnieB]

Originally Posted by Coreyw4023

What are most people spending on 4 new 12V batterys? Got a quote of 750 for trojans

Battery prices vary by geographic location.

Search online for pricing and you'll find T-1275's from about $175 or less each to over $300 each.

[mgutting]

Originally Posted by JohnnieB

Accurate load testing of deep-cycle lead-acid batteries take an expensive piece of specialized test equipment that discharges the battery(ies) at a constant amp flow over a measured period of time and automatically stops the discharge and timer when 1.75VPC (Volts per Cell) is reached. The results are typically Minutes @ 75A for 6V batteries or Minutes @ 56A for 8V and 12V batteries and compared to the rated runtime given by the battery manufacturer.

For example: A Trojan T-105 6V-225AH battery has a rating of 115 Minutes @ 75A and is the the runtime is half of that or less, the battery is at the end of its usable lifespan.

The battery load testers found in auto parts stores are designed to test SLI (Starter/Lights/Ignition) batteries and do not accurately test deep-cycle batteries.

While it doesn't measure runtime, you can attach a DVM to the battery pack and measure the pack voltage while going up hill to see how low it goes under load. If it drops below about 30V for a 36V pack, connect the DVM to individual batteries and find out if one or more is dropping significantly more than the others.

Putting new batteries into a battery pack that is over 6 months old should be avoided. The new batteries will soon acquire the same aging as the old batteries. If you find some batteries whose voltage drops significantly more than others, they can be replaced with good batteries approximately the same AH and age, or if new ones have to be used, the must be considered sacrificial batteries and will need to be replaced at the same time the rest of the pack is replaced.

In other words, replacing the batteries piecemeal doesn't work very well and will cost more money in the long run.

Thank you JohnnieB for sharing your knowledge. Very helpful for us just getting into the cart world.

[Ezgo4202]

Okay I'm very new to electric golf carts, I recently bought an 36v ez-go. I plan on leaving this at my farm and I don't want to put a crazy amount of money into it. I went to rural king and was looking at batteries. I found a 6v heavy duty battery and a 6v golf cart battery. Can anyone tell me the difference in the batteries? Thank you

[Cobra,1]

Post the specs of each battery.
The amp hours rating of a battery is what is needed to tell you which is the better battery.
A “heavy duty “ battery is not going to be the same as a golf cart specific battery nor is a deep cycle battery the same as a golf cart battery.