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Wed May 10, 2023 11:12 am

Hi guys (n' gals!) just wondering what sized/amp'd batteries you all use in your Beetles? I have a 1974 1200 Bug and the battery never quite seems big or strong enough..

I have read lots of different articles regarding sized batteries for cars etc, and it seems one can put in larger batteries than what were originally in them, but the last thing I want to do is destroy the electrics in the car, so any advice would be greatly appreciated - many thanks!

Wed May 10, 2023 12:34 pm

The '74 Beetle was the last year where you knew you would get a carb and not get FI. So unless someone upgraded your engine to FI, the most complicated electronics in your car might be the VR or the radio. Neither of them care what type of battery you have installed as long as it is a 12v (12.6v) car battery with at least 450CCA rating.

If you want a larger capacity battery, look for a 500CCA or 700CCA+ battery. It will work just fine. The problem you will have is finding one that will fit like the original. Most all battery groups (models) are taller than the original group 42 battery that came from the factory. The modern H5 battery is pretty close in size and has a larger CCA capacity.

You need to worry about the battery terminals making contact with the underside of the seat and shorting out. You can take precautions like placing an insulating layer over the top of the battery to keep the battery separate from the seat.

You may also want to look at AGM (Acid Gas Mat) batteries. These do not have any liquid acid in them and can be mounted sideways if needed. They also have high CCA and usually last years longer than the OE Series 42 battery.

Thu May 11, 2023 5:58 am

high CCA is great I guess but IMO Reserve Capacity is more of an important 'number' on a battery. Reserve capacity is simply the time in minutes that a 12V lead-acid battery can sustain a 25 amp load and remain above 10.5 volts. The longer the better.

Thu May 11, 2023 6:51 am

ashman40 wrote: The '74 Beetle was the last year where you knew you would get a carb and not get FI. So unless someone upgraded your engine to FI, the most complicated electronics in your car might be the VR or the radio. Neither of them care what type of battery you have installed as long as it is a 12v (12.6v) car battery with at least 450CCA rating.

If you want a larger capacity battery, look for a 500CCA or 700CCA+ battery. It will work just fine. The problem you will have is finding one that will fit like the original. Most all battery groups (models) are taller than the original group 42 battery that came from the factory. The modern H5 battery is pretty close in size and has a larger CCA capacity.

You need to worry about the battery terminals making contact with the underside of the seat and shorting out. You can take precautions like placing an insulating layer over the top of the battery to keep the battery separate from the seat.

You may also want to look at AGM (Acid Gas Mat) batteries. These do not have any liquid acid in them and can be mounted sideways if needed. They also have high CCA and usually last years longer than the OE Series 42 battery.
Thats great, so in a nutshell any standard 12v car battery will suffice then basically? Doesnt really matter on ampage?

Thu May 11, 2023 7:03 am

Malakite wrote: ashman40 wrote: The '74 Beetle was the last year where you knew you would get a carb and not get FI. So unless someone upgraded your engine to FI, the most complicated electronics in your car might be the VR or the radio. Neither of them care what type of battery you have installed as long as it is a 12v (12.6v) car battery with at least 450CCA rating.

If you want a larger capacity battery, look for a 500CCA or 700CCA+ battery. It will work just fine. The problem you will have is finding one that will fit like the original. Most all battery groups (models) are taller than the original group 42 battery that came from the factory. The modern H5 battery is pretty close in size and has a larger CCA capacity.

You need to worry about the battery terminals making contact with the underside of the seat and shorting out. You can take precautions like placing an insulating layer over the top of the battery to keep the battery separate from the seat.

You may also want to look at AGM (Acid Gas Mat) batteries. These do not have any liquid acid in them and can be mounted sideways if needed. They also have high CCA and usually last years longer than the OE Series 42 battery.
Thats great, so in a nutshell any standard 12v car battery will suffice then basically? Doesnt really matter on ampage?
The Group 42 battery that came with the VW is one of the shortest 12 volt batteries available. If you put in something taller you have to deal with the possibility the seat springs will short out on top of the battery and set the seat on fire. Also, unless you buy the cheapest garbage you can find, most Group 42 batteries available today have more CCA than the originals did when your car was new.

Here is a group 42 next to an AGM which is a lot more expensive.

Thu May 11, 2023 7:20 am

Q-Dog wrote: Malakite wrote: ashman40 wrote: The '74 Beetle was the last year where you knew you would get a carb and not get FI. So unless someone upgraded your engine to FI, the most complicated electronics in your car might be the VR or the radio. Neither of them care what type of battery you have installed as long as it is a 12v (12.6v) car battery with at least 450CCA rating.

If you want a larger capacity battery, look for a 500CCA or 700CCA+ battery. It will work just fine. The problem you will have is finding one that will fit like the original. Most all battery groups (models) are taller than the original group 42 battery that came from the factory. The modern H5 battery is pretty close in size and has a larger CCA capacity.

You need to worry about the battery terminals making contact with the underside of the seat and shorting out. You can take precautions like placing an insulating layer over the top of the battery to keep the battery separate from the seat.

You may also want to look at AGM (Acid Gas Mat) batteries. These do not have any liquid acid in them and can be mounted sideways if needed. They also have high CCA and usually last years longer than the OE Series 42 battery.
Thats great, so in a nutshell any standard 12v car battery will suffice then basically? Doesnt really matter on ampage?
The Group 42 battery that came with the VW is one of the shortest 12 volt batteries available. If you put in something taller you have to deal with the possibility the seat springs will short out on top of the battery and set the seat on fire. Also, unless you buy the cheapest garbage you can find, most Group 42 batteries available today have more CCA than the originals did when your car was new.

Here is a group 42 next to an AGM which is a lot more expensive.

wow - ok I am confused here now.. what would you personally recommend please? I just dont know what avenue to go down tbf

Thu May 11, 2023 11:46 am

Here is some advice:
(Easy option) Group 42 battery - Find a Group 42 battery. This is a drop in solution and works fine for most cars. As long as you don't have any excessive power demands (eg. high amp stereo, high amp starter, etc.) you will be fine w/ the Group 42 battery.

(Alternate modern batteries) Modern battery but may need fitting - Look for a more modern battery with similar dimensions to the stock battery. You can find most will have CCA ratings well above the OE 450CCA.
https://www.batteryequivalents.com/bci-battery-group-size-chart.html
Group 42:
242 x 175 x 175 (mm) 9-9/16 x 6-15/16 x 6-15/16 (inches)
The <7 inch height is the hardest dimension to meet.

Look for alternate batteries in the list with height dimensions around 7 inch or less. Then check that the width (~7 inches) is about the same so it can be held down with the stock battery hold down clamp. The length is the one dimension which can go a bit longer, but measure the space you have to determine the max length. You may need to cover the top of the battery w/ some type of insulating (plastic) cap to prevent the terminals shorting against the seat springs.

(Difficult to mount) AGM (Acid Gas Mat) or dry cell battery = These are non-liquid batteries and usually more expensive. But since they have no liquid they can be mounted upside down if you so desire. I've not found any that are less than 7 inch in height. But as long as the width is less than 7 inches you could mount them on their side. This complicates the mounting. You will need to customize how the battery is kept in place. Most AGM batteries like Optima Red Top are too tall to be mounted upright.

Thu May 11, 2023 1:15 pm

Malakite wrote: ...

wow - ok I am confused here now.. what would you personally recommend please? I just dont know what avenue to go down tbf

I would get the correct Group 42 battery, unless you want to spend more money for something smaller. I would not get a bigger than stock battery.

Thu May 11, 2023 1:29 pm

A taller battery that uses side terminals may fit and avoid the shorting risk on the seat springs. I haven't seen one yet.

Most Group 42 batteries fit but lately some lack the molded holes for the plastic positive pole protector to fit into. Mine lacked it, but I laid a folded rubber floor mat over it for some protection.

Thu May 11, 2023 4:12 pm

KTPhil wrote:
Most Group 42 batteries fit but lately some lack the molded holes for the plastic positive pole protector to fit into. Mine lacked it, but I laid a folded rubber floor mat over it for some protection.

This is great advice but make sure that "laying" a rubber mat over the battery is sufficiently held in place to ensure the mat does not slip off over time. Secure the mat with cable ties etc.

Ask me how I know!

Thu May 11, 2023 5:57 pm

Search Amazon or eBay for "battery terminal covers" something like these. They come in a variety of shapes.

Wed May 17, 2023 12:29 am

wonderful advice thank you ever so much..

I think I will go for a group 42 battery then... can I check if amp-age makes any difference as I guess there will be lots of different versions that I could purchase?

Many thanks

Wed May 17, 2023 4:37 am

I use a group 96 battery, 590-600 CCA. Stands a bit taller so I have a rubber mat between it and the seat bottom just in case. No issues after 3+ years and 27k miles. I was just out of town for 2 weeks so the car sat. Started right up after 15 days sitting.

Wed May 17, 2023 8:05 am

I used a group 65 because I found it on sale for $60. I covered the top with a thick rubber mat. No need to worry about CCA and all the other jargon. A VW does not require many amps to start and run. I have even used a lawn mower battery while restoring my bug.

Wed May 17, 2023 10:44 am

Malakite wrote: … can I check if amp-age (amperage?) makes any difference…
Batteries can be rated using different metrics. Back in the ‘70s VW used amp-hours (Ah) as the measure for the proper sized battery. Ah is a measure of current the battery provides over a 20hour period. That is a less common metric now days. Here is the page from the ‘74 Beetle Owner’s Manual showing the Ah rating as 36 Ah.

You will normally see Cold Cranking Amps (CCA) as the rating for today’s automotive batteries. CCA is a measure of the current the battery provides over a 30sec period while under a heavy load (eg. while cranking the engine).

More info on the differences here:
https://www.batteryequivalents.com/how-to-convert-cold-cranking-amps-cca-to-amp-hours-ah.html

The minimum battery for a stock Beetle is around 420CCA. Any battery with a higher CCA rating will meet the needs of your Beetle. Over the 50yrs since your Beetle rolled off the factory line battery technology has improved greatly. It is actually rather difficult to find a 12v automotive battery that does not exceed the rating needed for a Beetle. As mentioned, even modern lawn mower batteries have the needed power to crank the ACVW engine. :shock:

Wed May 17, 2023 1:45 pm

The stock sized battery fits, use it. Larger batteries risk having the terminal short circuit on the rear seat bottom springs, and this can and has lead to fires. That happened to someone I know, and that was cause they used a battery without the factory battery protector over the terminals. A fat person sat on the seat and pushed it down enough to short it out.
If your battery is good you may have hard starting problems do to bad connections, there are many connections in the path that can cause problems, there is even a ground strap under the car at the tranny nose that can cause problems if it is loose or dirty.
So get a stock battery to fit the stock battery location AND besure to sue the battery clamp strap and battery top cover so as to prevent a fire under the seat.
Batteries typically will have a date sticker on them at the store, get the newest one, avoid batteries in excess of 6 months old, one month old or less is best. I usually shop around to find one less than 3 months. when left on shelf at store they self discharge, and if left for months in this state of partial discharge the battery will be permanently damaged, giving it a much shorter life than it should.

Tue Jun 06, 2023 1:48 am

zerotofifty wrote: The stock sized battery fits, use it. Larger batteries risk having the terminal short circuit on the rear seat bottom springs, and this can and has lead to fires. That happened to someone I know, and that was cause they used a battery without the factory battery protector over the terminals. A fat person sat on the seat and pushed it down enough to short it out.
If your battery is good you may have hard starting problems do to bad connections, there are many connections in the path that can cause problems, there is even a ground strap under the car at the tranny nose that can cause problems if it is loose or dirty.
So get a stock battery to fit the stock battery location AND besure to sue the battery clamp strap and battery top cover so as to prevent a fire under the seat.
Batteries typically will have a date sticker on them at the store, get the newest one, avoid batteries in excess of 6 months old, one month old or less is best. I usually shop around to find one less than 3 months. when left on shelf at store they self discharge, and if left for months in this state of partial discharge the battery will be permanently damaged, giving it a much shorter life than it should.

Very interesting. OK so I have a battery that is a standard size but is rated at 450CCA, 60Ah, and is a 12V - I presume that this is ok?

Wed Sep 25, 2024 9:34 am

Getting ready to purchase 2 batteries, for a 73 Thing and a 67 Split bus. At Autozone or Oriellys, I was looking at about $400 b4 exchange for 2. Since I have a Rural King farm supply store within 50 miles of me I thought I would check to see if they have group 42 batteries.

https://www.ruralking.com/rural-king-classic-automotive-battery-42-60

This battery has basically the same specs as the Duralast batteries sold by the auto chain stores and is probably produced by the same supplier. Anyone have any experience?

Wed Sep 25, 2024 10:12 am

I have an Advanced Auto group 96 silver battery in my '73 Super daily driver. The battery is 5 years old and going strong. I only had to recharge it once early on after installing it months before the car was road-ready, so it sat unused for weeks.

Wed Sep 25, 2024 10:28 am

I used the original size battery but an AGM as there is no acid sloshing around. I've let the car sit for 8 months and it still starts up. I put some of the original insulation on top of the battery so there is no way it could short out.