Putting an AGM battery in a Group 53 Case

[RKF]

Finally, I scored a NOS Delco Group 53 battery, which I plan to gut and install an AGM inside. I know this has been done numerous times, but I don't know which AGM battery will fit in the case and provide sufficient cold cranking amps to start a Corvair.

I's appreciate any information regarding the best AGM battery to use in this situation and any other tips anyone may have.

[Frank DuVal]

I have no suggestions, but good news, the Corvair engine starts easy, and the group 53 was a low amp-hour battery from the start. Back on CCF there were posts of small AGM batteries being used. They look so small and out of place, not an issue once you put the 53 cover over it.

[jfreez]

There are a ton of amazing batteries out there in a small case these days.
just search High output car stereo battery and you will see some very good ones.

here is a link to one I like (but I have not put one in a Corvair), you can look at the dimensions and see if it works for you


https://www.sonicelectronix.com/item-46 ... P1200.html

[vairchet]

Too bad you're about to ruin an NOS battery, I could've gave you these:

[RKF]

There are a ton of amazing batteries out there in a small case these days.
just search High output car stereo battery and you will see some very good ones.

here is a link to one I like (but I have not put one in a Corvair), you can look at the dimensions and see if it works for you


https://www.sonicelectronix.com/item-46 ... P1200.html

The specs on that battery are impressive. Unfortunately, it's a little too fat to fit into the Group 53 case.

[Frank DuVal]

Hmm, that's a good point. Have you added acid and charged the dry charged battery? it might work for years.

[RKF]

Hmm, that's a good point. Have you added acid and charged the dry charged battery? it might work for years.

There are a couple of reasons I need to convert the battery to AGM. First, I have heard from two reliable sources that NOS batteries of that vintage don't work very well. Second, I need to change the polarity of the posts of the Group 23, so the negative is on the right and the positive is on the left.

[jfreez]

Try this link for a whole list of high output car stereo batteries, I bet you will find something that works

https://www.sonicelectronix.com/ci228-a ... N-yfraDvTv

[Frank DuVal]

I assume "group 23" is a misprint, and you mean group 53. 53 is the stock battery for early Corvairs, reversing the terminals will mean the car will not be correct as built. The stock terminal location of a group 53 worked fine for a million + Corvairs.

[/color]


When this group 53 battery is installed in the battery area both terminals are away from the engine, safely tucked up under the left quarter.

[RKF]

"When this group 53 battery is installed in the battery area both terminals are away from the engine, safely tucked up under the left quarter."

I see what you mean. Thanks!

[American Mel]

I never looked at them close, but I always thought "Stereo Batteries" were of the Deep Cycle variety.

[Frank DuVal]

Right. So in lead acid design there are two types, starting and deep cycle. Starting types are designed to provide high current for a short time and get recharged before they are say half depleted. A Deep Cycle type can be taken down to almost zip, rule of thumb is 20% (80% depleted) and then brought back on a charger. But they are not good for high current draws.

That being said, I used a group 27 deep cycle as the "jump" battery in my shop for years. Made a cart (two wheels like a hand truck) for it and a set of 4 awg cables, worked great! But of course it usually just had to supplement the battery in the car.

[jfreez]

many of the newer car stereo batteries have much higher CCA ratings. they tend to be dry cell units like the big off-road ones. A lot of new cars don't have space for a second battery, so for the big audio systems most people want a battery that can handle both starting and large reserve capacity. if you take a look at the ratings of some of the batteries on the link I posted, you will see some impressive numbers for their size.

I have also heard that there are some lithium ion car batteries out there, but I haven't looked into their specs