Saturday, January 24, 2009

Possible Design Defect

In my opinion there is a design defect in the Electro Automotive VW wiring scheme:

I have lost two 12 vdc vehicle aux. batteries. Last week, the second aux. battery ended up fully discharged … and frozen. (The temp in my barn has been in the 0-25 deg. F range.)

Remember from my last blog entry, I discussed long maintenance charges?

Here's the problem:

Whenever external power is plugged into the car outlet for charging, the 12vdc fan is activated to ventilate the rear battery box. The fan is powered from the aux. battery During this time, there is no recharging of the aux. battery. It's the same as leaving the car lights ON, when leaving the car ... albeit, with a much lower current draw.

I frequently plug in my charger in the afternoon, upon return home, and leave it ON all night, as my PFC-20, turns OFF at the appropriate time. It seemed like there was no downside to this technique. Several times, when the power was plugged in for extended times, even with the charger OFF, the aux. battery became fully discharged, eventually resulting in my buying a new battery.

During the worst of this winter, my car stays in the barn. In order to preserve the batteries, I use my PFC 20 to frequently charge the batteries. Last week, I left the charger on for 24 hours, in 10 deg. weather, with the charger set at the appropriate float voltage. When I checked later, I discovered the fan stopped, the aux, battery dead ... and frozen! I now have to buy another new battery.

I think it's a poor design to run the battery box ventilator with a 12vdc fan, powered from a source that isn't kept charged. I plan on replacing the fan, ASAP, with a 120vac fan that runs from external house power whenever the vehicle is plugged in.

If this situation applies to you, I suggest you replace the 12vdc fan with a 125vac fan, wired in appropriately.

Just my opinion.


Roger Daisley said...

Electro Automotive replies: "We did not intend or expect chargers to be left plugged in for so long. This is an issue we are already addressing."

Lance said...

Thanks for this very useful tip. I didn't realize they run the ventilation fan from a 12V source. I will check with ElectroAuto when I get closer to that step in my kit and see if they have any updates. I also wanted to ask them what is different about the motor / adapter plate arrangement so that I will not need to modify the right side mount.

Lance said...

Where'd you find those cool clear tail light lenses?

Roger Daisley said...

Lance: Good Luck on your conversion. Don't hesitate to phone or email me, if you run into problems. (Email me directly for phone number)

I bought the clear rear lights on-line about five years ago and forget where that was, but I'm sure you can find similiar items easily.