Battery Going Dead

[newmexicomatt]

My battery is dead, once again. My mechanic is checking into the charging system...but I need to get another battery. Even though I had kept up on the water level, the battery was bone dry. He's thinking that the location in the engine compartment might be a hot spot that is causing the battery to dry out. He wants to replace it with a gel type battery. I'm looking for recommendations for battery replacement. THanks!

[Barry Wolk]

I have the tar-top by Antique Battery. I had a bad experience with the first one but the second one is great. They don't do well when fully discharged. All you have to do is pull the clock and interior light fuse in the Fall and the battery will be fine in the Spring. A battery tender really helps.

My friend has had to replace his 3 times as he forgets to pull the fuses before he puts it away. Mine is now 3 years old and fires up the car just fine.

I would bet that your clock is the culprit.

[Phil Gevertz]

I would bet on the clock. I had continual dead battery issues. Once the fuse was taken out of the clock, everything has been fine since over (2 years)

[Ian Cowie]

My discharging problem ended up being ... the ash tray lights!

Somebody had wired them up all wrong. The end result was that the lamps were on all the time, but who knew? Car was only used during the day and the ash tray covers are always closed! I would use the car one weekend and then next ... dead battery. Charge it up and it would be good for another week or two.

Great technique to trace any current draw is to disconnect the negative cable from the battery. Pop one end of all the fuses out but leave them in place and then reconnect the negative cable -BUT- connect it through an ammeter. Most DVMs (digital voltmeter ... or even the older analog meters) will have a 10 Amp setting. You will now see any direct connect draw ... such as the power windows, power seats. However there should be no current draw at this point if nothing is running. If there is you have a short. I had steel wool that had fallen into the power window switches and that would occasionally cause problems until I found that problem.

Reconnect each fuse in turn and monitor the ammeter. The clock fuse should draw some current ... is it continuous or is it just drawing current to wind the spring ... I have no idea about that but other members may be able to comment on that. How long will a decent battery last with the clock always connected? I feel a decent battery will last all summer without having to disconnect anything. Yes, up here we have seasons, "drive the nice car" season and "put away the car for many months" season ... :(. If you are not using the car for several weeks, then I would either pull the clock fuse or disconnect the negative battery cable.

[Barry Wolk]

A 12-volt light bulb or test light will serve the same function if you don't have an ammeter.

Using a single-filament bulb hook the ground to one fuse clip and the power lead to the other.

If there's current draw the light will light as the filament is acting as a resistor.

[Don Henschel]

I would bet on the clock. I had continual dead battery issues. Once the fuse was taken out of the clock, everything has been fine since over (2 years)

What a horrible clock with a horrible continuos drive motor:mad:! Everything else uses that good old winding solinoid used way up into the seventies.I cleaned my 50 Merc clock back in the eighties and it hasnt failed since. I never used to disconnect my battery on this car and it wouldnt go dead.

[Ron Busche]

were can I get a batterie for my MrakII none can be found in my town

Ron Busche
rbus1310@cableone.net

[Barry Wolk]

Hi Ron,

I would highly recommend the Antique Auto battery tar-top that looks original, but had a modern coil core. No fluids to leak or boil out.

They aren't cheap, but provide reliable service without rusting your hood and eating your hood liner.

The only down side is that you have to use a 12-amp or less charger on them.

[Keith W Colonna]

I also have several of the classic original look "tar top" batteries that I got from the Antique Auto Battery Co. There is another supplier who advertises in Hemmings or the LCOC. They apparently get them from the same manufacturer.
MKII Enterprizes also sells a glue on veneer cover which gives the outside the original unique factory logo specific to the MKII. I haven't put mine on yet....but it looks great.
I struggled for years with the old wet cell batteries...trickle chargers, etc. they leach gas which destoys nearby paint and the hood liners...they boil over, etc.....don't bother with them. The dry battery from AAB is acutally an Optima battery inside....requires no water or acid!!
Lastly, I have the un-screw type battery disconnecter. Several members have advised against them.....I agree. They are not reliable. However, if you completely unscrew them....and take the two halves apart...it is easier than taking the terminal off each time. But otherwise, they are not reliable.

[Barry Wolk]

Nice to see you back, Keith.

[Sean Rollins]

2536I found this style of disconnect at a local parts store, and have been more than happy with it. There is never a question about wether the terminal is engaged or not.

[Barry Wolk]

The knife switched can overheat, too. I have this power switch on my trailer.

http://toolmonger.com/wp-content/uploads/2008/07/BatterySwitch-450.jpg

It actually can be mounted through the firewall or under the dash so that you'd have to get into the car to put power to everything.