VCCA Home Forums TECHNICAL - GENERAL Electrical - 12 volt What BCI battery

I am converting a '41 1/2 ton PU (AK) to 12 volt. I want to keep battery in the original location. What BCI (group) and manufacture would you recommend? I have looked at Optima Red Top group 25.

When I converted my 53 I went to the parts store with the measurement of my stock battery and a tape measure. I measured until I found a close fit and took it home.

I agree with Tiny's approach. Find the largest battery that will fit the tray Then use a few pieces of wood painted black to help hold it in place.

Even the 6 volt batteries you buy today are not the same physical size as what was in the car. I had to make spacers to fit a current 6 volt battery into my '37.

I have not noticed any change in the size of a 6 volt, Group 1 battery, in the 55 years that I have been buying them.
I find that they always deliver satisfactory performance when the original 6 volt, starter, generator, and voltage regulator are in good condition. I have never had a need to convert a 6 volt system to 12 volts.

Mike

I appreciate the concept "that if ain't broke don"t fix it" but in this case we need a 12 volt system for the new motor and accessories .

Mike,

I agree that the size of the Group 1 battery has remained the same over the years. My experience was with my '37 which used what sometimes has been referred to as Group 2 battery which is slightly larger.

I am not aware of what size battery the '41 pickup used.

Rusty,
I have never heard of any old 6 volt Chevy that used anything other than the Group 1 battery. My 1935, 1936, 1937, 1938, 1939, 1940, 1941, 1942, and 1946 all have had the group 1.
Tell me more.

Mike

The 1937-1939 cars used a different size battery. It was a little lower amd longer. A group 1 will fit but you have to make sure the metal cover in the floor does not contact the posts.

Gene is correct about the battery height in those year cars. Thankfully my '37 still had the plywood battery box cover.

The 1938 and 1939 had a metal cover with insulation on the under side.
Chevrolet said the lower battery was ncessary due to the new lowe floor.

A Group 1 is taller than the battery that came stock in a 38. It works but is very close to the bottom of the hatch door. I've got it tied down well so it won't bounce and arc on the door. The stock battery was 10 9/16 L x 7 W x 7 7/16 H. This Group 1 is 9 X 8.67 X 8.75, almost 2" taller than stock.
https://www.powerstridebattery.com/group-1-battery

If you are worried about the battery shorting on the cover cut a suitable sized section out of an old tire tube and secure it over the battery. This will insulate under most circumstances.
Tony

. By the way, the easy way to distinguish a group #1 from a Group #2 six volt battery, is that the posts are reversed. The problem is that the negative ground (earth) is supposed to be connected to the transmission. The braided cable is too short to reach the transmission on a group #2 so it gets bolted to the frame. When you step on the starter, the rubber motor mounts require the negative to find a path thru the choke cable and steel gas line. .
. The group #1 was used on the 4 cylinder cars when it was mounted on the left. (Picture #1). GM used the same photo in later years tho by 1937 the battery was on the right side and used a group #2 as in the second photo. .
.PS: Put a shunt behind your amp meter and read last paragraph on this web page to save your fuel gauge. <http://home.znet.com/r1937/Fuel.htm> . Lou