[T3] Ray-O-Vac battery

Jim Adney jadney at vwtype3.org
Sat Jul 17 14:34:26 PDT 2021

On 17 Jul 2021 at 15:50, Gary Forsmo wrote:

> With that history, is it time to buy and install a new 12 Volt Battery?

Frankly, it sounds fine. Resting voltages seldom stay above 13 V, and the 
slowly rising voltage while on the maintainer are exactly what I'd expect. The 
maintainer current may be small enough that you could do this for a couple 
more weeks. The maintainer current is likely to depend on the line voltage at 
your basement outlet.

You could probably put this battery in your '69 now and drive it comfortably, 
but I'd put the maintainer on it while it's parked. Some of the lugs on the 
bottom of the fuse box are hot all the time, so this is a convenient place to 
connect the maintainer while the car is parked and the key is OFF.

The voltage while charging rises at first, then there's a LONG plateau where 
nothing seems to be happening, then a final rise to above 14 V. It sounds to 
me like you're still in that long plateau.

If this battery has cell covers that you can remove, look down there and see 
what you can see. There will be 3 different "plates" visible: pos plates, neg 
plates, and brown paper separators.

The pos and neg plates will both be white/grey when discharged. One of 
them will slowly shed the grey and turn black (or is it brown?) Charging is 
complete when the grey is completely gone from those plates.

Leave the cells covered when you're not looking down there. Occasional 
bubbles from the charging will toss out tiny drops of acid if you don't. These 
can be thrown farther than you'd expect.

I''ve never seen a Ray-O-Vac lead-acid automotive battery. Where did you 
find that? The brand name is relatively unimportant. All our US batteries are 
made by just 2-3 manufacturers. They will make batteries with any Brand on 
them and to any spec.

BTW, I finally managed to find a good listing of battery sizes and post 
configurations, to see what we could replace our Group 42 batteries with. It 
looks like a Group 90 is what to look for. Group 90 is the same as Group 42, 
with the addition of mounting lugs on the ends, in addition to the sides. 
Groups 91, 92, & 93 offer stepwise increases in length if you think you need 
more power, but I've never seen the need in our cars.  

Jim Adney, jadney at vwtype3.org
Madison, Wisconsin, USA

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