Posted By: 1MYTGTX
How to install an AGM battery in your dead Group 27 - 10/03/10 12:53 PM
This question has come up a few times in the past weeks on how to install an AGM (Absorbed Glass Mat) battery into your dead acid filled Group 27 restoration battery. Originally I wrote up a little "how to" that was buried in the middle of another topic. I figured I'd make its own thread to possibly add to the tech archive.....
Basically, to gut the battery you need a large metal pail, baking soda, fresh water, long heavy rubber gloves, face shield, eye protection etc....
Small disclaimer....
YOU ARE DEALING WITH HIGHLY CORROSIVE BATTERY ACID
PROCEED AT YOUR OWN RISK
I TAKE NO RESPONSIBILITY FOR YOUR ACTIONS
I drilled holes at the bottom of the case to drain as much of the acid as possible. I work in a bus maintenance facility that has provisions for acid battery flushing & washing so this step was easy for me.
After thoroughly neutralizing the battery as much as possible (the glass matting will still hold acid) I figured I would try to cut a square out of the bottom of the case & all the guts would fall out....NOT!
The case is molded with plastic separators built into it to separate each cell.
I have heard others cutting the top of the battery off but I wanted to hide this battery as best as possible & I didn't want any potentially visible seams.
Secondly, the case is VERY thick plastic on the bottom & fairly thin on the sides. You have to be careful not to crack the side of the case when you are breaking out the plastic separators molded inside.
I used a whiz wheel for this along with a good dust mask because you WILL be black when you finish cutting the bottom out cell by cell.
Starting at one side of the case, after the bottom of the cell is cut out, each glass mat is separated by a lead plate which is attached to lead lugs at the top of the battery. There are aprox 6 lead plates & mats per cell. These have to be wiggled & broken off the lugs to remove. AGAIN WEAR HEAVY NEOPRENE ACID RESISTANT GLOVES!!
After removing all the plates & mats in one cell, break out the plastic separators, cut out the bottom of the next cell & move on till they are all out.
Wash out the case & then proceed to take out all the lead plate retaining lugs except for the 2 that the posts connect to. You have to take the others out to fit the new battery in the case. I used a Dremel tool with a small cut off wheel to cut through the lead.
Lastly drill out a hole in each post lug & make up some short battery cables to connect the new battery to.
Sorry I don't have any pics of the messy gutting procedure but here is a pic of the case that shows what I mean by the molded in separators & the lugs as well as the small battery cables I made ...
The battery I used was an Odyssey PC925
Odyssey batteries
....see the difference in size (also about 25lbs lighter)
Here is a close up of the post terminal & small cable.
You can see the molded in plastic separators I had to carefully break out with pliers etc....
I got 6 years 8 months out of my lead acid resto battery and it was still going (although it started dying if I didn't use the car for a week..that's why I did this....)
I have since added pieces of Styrofoam to take up the space in the case so the smaller battery doesn't flop around.
There's a tiny battery cranking that big bock 440 engine over? Where?
Hopefully this helps!
Chris
Basically, to gut the battery you need a large metal pail, baking soda, fresh water, long heavy rubber gloves, face shield, eye protection etc....
Small disclaimer....
YOU ARE DEALING WITH HIGHLY CORROSIVE BATTERY ACID
PROCEED AT YOUR OWN RISK
I TAKE NO RESPONSIBILITY FOR YOUR ACTIONS
I drilled holes at the bottom of the case to drain as much of the acid as possible. I work in a bus maintenance facility that has provisions for acid battery flushing & washing so this step was easy for me.
After thoroughly neutralizing the battery as much as possible (the glass matting will still hold acid) I figured I would try to cut a square out of the bottom of the case & all the guts would fall out....NOT!
The case is molded with plastic separators built into it to separate each cell.
I have heard others cutting the top of the battery off but I wanted to hide this battery as best as possible & I didn't want any potentially visible seams.
Secondly, the case is VERY thick plastic on the bottom & fairly thin on the sides. You have to be careful not to crack the side of the case when you are breaking out the plastic separators molded inside.
I used a whiz wheel for this along with a good dust mask because you WILL be black when you finish cutting the bottom out cell by cell.
Starting at one side of the case, after the bottom of the cell is cut out, each glass mat is separated by a lead plate which is attached to lead lugs at the top of the battery. There are aprox 6 lead plates & mats per cell. These have to be wiggled & broken off the lugs to remove. AGAIN WEAR HEAVY NEOPRENE ACID RESISTANT GLOVES!!
After removing all the plates & mats in one cell, break out the plastic separators, cut out the bottom of the next cell & move on till they are all out.
Wash out the case & then proceed to take out all the lead plate retaining lugs except for the 2 that the posts connect to. You have to take the others out to fit the new battery in the case. I used a Dremel tool with a small cut off wheel to cut through the lead.
Lastly drill out a hole in each post lug & make up some short battery cables to connect the new battery to.
Sorry I don't have any pics of the messy gutting procedure but here is a pic of the case that shows what I mean by the molded in separators & the lugs as well as the small battery cables I made ...
The battery I used was an Odyssey PC925
Odyssey batteries
....see the difference in size (also about 25lbs lighter)
Here is a close up of the post terminal & small cable.
You can see the molded in plastic separators I had to carefully break out with pliers etc....
I got 6 years 8 months out of my lead acid resto battery and it was still going (although it started dying if I didn't use the car for a week..that's why I did this....)
I have since added pieces of Styrofoam to take up the space in the case so the smaller battery doesn't flop around.
There's a tiny battery cranking that big bock 440 engine over? Where?
Hopefully this helps!
Chris
