1993 Ezgo Battery Set

[fencible39]

My 1993 is kept in an unheated garage. Last year I had a two year old set of batteries freeze, although I charged once per month. One battery burst, so I replaced the whole set. This year I made a 2x4 frame, slid it under the batteries, and put in two 40 watt light bulbs that started when it got below 35 degreees. No freezing this year.
My question: I have a LED voltage indicator that shows actual voltage in the set. When I fully charge, the set ends up around 38 volts. After driving on several short trips in my yard it drops to around 36 volts.
Would someone please tell me at what voltage level I should be charging the set at?
Obviously don't want to lose this set.
Thanks. Dave

[BBBHC]

Here is a generic soc chart.
Johnnie_Bbattery%.jpg

From my understanding, different battery manufacturers have slightly different numbers. JohnnieB put this together and I believe he also has another one that has specific numbers for different manufacturers too, but I don't remember where it is posted. Hopefully he'll chime in, or someone else who has that information.

Good idea on the light bulb setup! I might have to steal that!

[yurtle]

I posted a while back, you can buy purpose made battery warming heating pads. As to freezing/splitting, what temperature do you batteries see, worst case? Fully charged batteries have a pretty low freezing point.

A heater's good for more umph - a technical term - once you want to drive in the cold.

[Cobra,1]

General info.
Lower the batteries charge,higher the freezing point.
I charge batteries every two weeks during off season to keep voltage and specific gravity up.
Low specific batteries will have higher(closer to waters) freezing point. Keep batteries charged.
Nice idea of battery warmer��

[Mooncarter]

fencible, I would take some readings with a good digital voltage meter and confirm those voltages.

to BGW

[yurtle]

Originally Posted by Mooncarter

fencible, I would take some readings with a good digital voltage meter and confirm those voltages.

to BGW

Concur. "around 36 volts" is meaningless, and is dead for a 36 volt pack.

Here's a link to the battery warmer I mentioned. Starting off the day with warm batteries is better than starting off with freezing temps.

https://www.amazon.com/Zerostart-280...56125160&psc=1

This is just a random Google search, and not what I'd recommend, as I have no experience with "cold".

[Mooncarter]

[fencible39]

Originally Posted by BBBHC

Here is a generic soc chart.
Attachment 185826

From my understanding, different battery manufacturers have slightly different numbers. JohnnieB put this together and I believe he also has another one that has specific numbers for different manufacturers too, but I don't remember where it is posted. Hopefully he'll chime in, or someone else who has that information.

Good idea on the light bulb setup! I might have to steal that!

That's a helpful chart. I have a pic of the simple setup if I can find out how to insert it. It just slides under on a cement floor and it worked for me. The yellow thing on the plug-in side of the cord is a temperature relay that turns it on at 35 degrees.

[fencible39]

Originally Posted by yurtle

Concur. "around 36 volts" is meaningless, and is dead for a 36 volt pack.

Here's a link to the battery warmer I mentioned. Starting off the day with warm batteries is better than starting off with freezing temps.



This is just a random Google search, and not what I'd recommend, as I have no experience with "cold".

Thanks, it would take two of those to warm all the batteries. My design light-bulb warmer works fine.

[fencible39]

Originally Posted by Cobra,1

General info.
Lower the batteries charge,higher the freezing point.
I charge batteries every two weeks during off season to keep voltage and specific gravity up.
Low specific batteries will have higher(closer to waters) freezing point. Keep batteries charged.
Nice idea of battery warmer��

Thanks for that info.

The temp in my garage got in the single digits that year when it froze.

The digital LED gauge I installed shows the actual voltage of the set. I'll keep it above 36.5 and charge it at that point.