26 Size Battery for Thames 300E?

[BigFred]

I'm finally getting back to my 1959 Thames 300E project after life & weather got in the way for a while. I'm getting ready to do a test fire-up (first one for this vehicle since the 1970's) and need to buy a battery. I can get a good deal on a new size 26 size battery with 525 CCA's. I'm not at all familiar with this small battery size (a bit smaller dimensions than a 24 size battery) and was wondering if it would suit my purpose. I don't yet really want to invest big bucks in a battery for a project that may not go anywhere. Can anyone help?

[Brett Wilkie]

I would say it should be okay, I am guessing that you won't be using your car in cold winter conditions anyway?? I have been using a slightly bigger battery in my Prefect without a hint of trouble. If your posts are in the correct position and your connections/grounds/starter motor are good you should be fine.

My battery

[JAN]

The battery's size merely dictates how long it can continue to deliver a given output. The 100E is, or should be, very good at starting so doesn't take a lot from the battery.

[peteleo]

Physical size has nothing to do with battery capacity rating.

Auto batteries are rated by AH, amps per hour, and CCR, cold cranking amps. Battery needs to get a high CCA rating no matter the size.

[DonG]

Yah, 12 volt is 12 volt. This is one time bigger comes up short. However needs to be Positive ground.

[JAN]

If we're getting technical, the Amp Hour rating is useful only as a comparison between batteries output. Theoretically, a 40 AH battery will put out 40 amps for one hour or one amp for 40 hours, which doesn't work in practice. The Reserve Capacity is more accurate, and is the time in minutes that the battery can deliver 25 amps at a temperature of 25 degrees until the battery is fully discharged, i.e. its voltage drops to 10.5.

But generally speaking, the bigger the battery of the same type, the greater its capacity.

[peteleo]

Jan,

Don't know where you are getting your info from. You may want to check this out esp. under CCA: http://www.carsdirect.com/car-maintenan ... ur-and-cca

Pete

[JAN]

Maybe things are different in the States, but that's how we do things over here. It's what I've been teaching for the last fourteen years!

[BigFred]

Thanks for all of the feedback and link. I think I'm going to get the group 26 battery. I'll look into getting a higher quality (and larger dimension) battery later if it looks like this Thames will someday be roadworthy.

Regarding the "needs to be positive ground" comment, isn't that just a matter of ensuring the battery cables are on the correct posts (i.e., ground cable on the positive post)? I did see that they offered the posts in both configurations (positive at one end on one model and positive at the other end on the other model {designated "R" for reversed}).

[DonG]

Big Fred, If you have got all original equipment in the van then it will be positive ground as the manufacturer set it up that way. so attach plus to plus and neg to neg. But keep in mind if you want to run down to walmart and pick up a radio you will probably start a meltdown (fire) in your new radio. All American cars are neg. ground. FYI. Dong.

[BigFred]

Big Fred, If you have got all original equipment in the van then it will be positive ground as the manufacturer set it up that way. so attach plus to plus and neg to neg. But keep in mind if you want to run down to walmart and pick up a radio you will probably start a meltdown (fire) in your new radio. All American cars are neg. ground. FYI. Dong.

Yeah, for now I am thinking of keeping everything 100% original. So it'll be positive ground with no electronic accessories.

[BigFred]

Minor update... I installed that Group 26 battery with the 525 CCA's. I gave the starter knob a few quick pulls, the starter did engage the flywheel, and the flywheel did turn a few revolutions. (I have the transmission removed and the panel around the shifter removed, so I can see the starter shaft and the back of the flywheel from the driver's seat.) That's as much as I wanted to do at this point. Looks like this battery will work fine for now. I'll now be prepping the rest of motor for the test fire-up. Maybe in the next few days.

[DonG]

Big Fred, Just a reminder to put oil in the cylinder tops before starting since its been sitting around so long. Also, if your anywhere near NH, I have some extra parts.

[BigFred]

Big Fred, Just a reminder to put oil in the cylinder tops before starting since its been sitting around so long. Also, if your anywhere near NH, I have some extra parts.

Already squirted Marvel Mystery Oil in the cylinders a couple of times. Motor turns relatively freely using the hand crank. I live in southern New Jersey.