VCCA Home Forums TECHNICAL - 1945 AND EARLIER 1929-1932 Optima Battery

Will a standard 1929 generator maintain an Optima Rd Top battery?

Any generator will charge a battery as long as the vehicle is not consuming all of the amperage the generator will produce. The situation is really how long will it take to recharge any battery after you have started the car. Obviously the more amperage a generator will produce the quicker it will re-charge the battery.

I will let one of the experts respond abut the output of a '29 generator. I expect it is a three brush design which means that it is a fixed output generator. If so there is no regulator which decrease the amperage output as the battery gets to full charge.

If all the electrical units on the vehicle are the same as original then the generator will maintain the battery fine. The system was designed to use only a certain amount (draw) of power and the generator designed to MAINTAIN that system usage. That does not mean if you have a short or for some reason drain the battery completely that the generator will easily or fully charged the battery. With a higher capacity battery it will take more power to fully charge the battery and possibly overheat the generator. It is always a good practice to use a battery charger to recharge a drained battery.

When the output is set correctly on the 943J generator, which is the correct generator for 1929, the output will be between 8 and 10 amps continuous while driving, and that will charge the battery with no problem. However, if the lights are on the output of the generator will greatly decrease down to a minus 1 or 2 amps discharge at idle and up to 1 or 2 amps charge on average while driving.

I have an Optima Red 6v and when not in use it is on the bench connected to the Battery Tender :)

Optima Charging

I agree. Didn't have the thinking hat on when I was replying. I do think still best to use a charger if the battery is drained. Don't know how long it would take to completely charge at 8-10 amps. One just might have to go on a long daytime trip.

Thanks to all.

I had no idea if the way all the new batteries are made, and if that construction meant a regular almost 90 year generator would not keep them charged.


What a great bunch you are.

I also have an Optima red top in my '31 with original rebuilt generator. I added the internal regulator so it doesn't overcharge. It works great. I do have a hidden master shut off switch to keep any drain from happening and a trickle charger set up in the right hand well pan to keep it topped up.

The internal regulator is made by James Peterson in Oregon. I don't have the contact info but I'm sure somebody here does.

Happy Motoring and Merry Christmas from Texas! - Bill

Thanks for the addition Bill. I keep a trickle charger on the battery always when not in use. And for whatever reason my regular 6v has held up for several years past its normal dead date. I am thinking it is however, about time to go new.


Merry Christmas To All

I know this is an older post but maybe some of you are still active on this forum. I have to buy a battery for my new to me 1941 Special Deluxe and as a fan of Optima batteries, I was wondering how you hold down an Optima battery on these old cars? Someone said there was a cover you could put over an Optima to make it look similar to original batteries. Do you know anything about that?

The covers are still out there, but have to see if it suits and fits your application !! do a google, siri, apple search for: 6v Optima Battery Case

i just use a strap to hold it in my 1929, this is the 6v Optima Red top of course, they are thin vs standard 6v. it has to sit at an angle as the Optima is longer than a stock 6v.


few that came up when i did the search

they make a hold down clamp for them, here is one: https://optimatrays.com/products/6v-rigid-clamp-tray

here is an empty case you can drop it in (have to verify fitment of case to your application): https://www.tartopper.com/product/optima-six-volt-coming-in-september-2018/

here is ebay for other style: https://www.ebay.com/itm/364680870445?hash=item54e8ac7a2d:g:tRwAAOSwqu9UzxkP

Willard Case: https://g518parts.com/?product=willard-battery-case