Battery Problems

[ken]

I have had an ongoing problem with my Cabriolet battery going flat in just a few days. Battery checked....no problems. I checked for a draw on the fuse box with everything switched off...no problems.
Alternator checked for possible problems...all ok. In desperation I took the car to a local garage they rechecked everything and couldn't find anything that would drain the battery in such a short time. By chance I was chatting to a chap who is rebuilding an Audi and he told me to isolate the battery case from the body of the car. I followed his advice and surprise surprise problem solved. Strange eh!!!

[rog8811]

Re: Battery Problems

What engine out of interest? My berli had the same problem so I put an isolator on the battery terminal, the only thing I need to do is reset the clock but it is a small price to pay for knowing it will start.
Mine is a 2.0 pinto, my wife had a MK 111 Cortina years ago and she clearly remembers regular flat batteries with it. Is it something related to the diode block for the Alternator maybe?

[ken]

Re: Battery Problems

I've got the same engine 2.0 pinto. I hope this will solve your problem too.

[dogoncrazy]

Re: Battery Problems

What did you use to isolate the case from the body?

[Mike]

Re: Battery Problems

I have had an ongoing problem with my Cabriolet battery going flat in just a few days. Battery checked....no problems. I checked for a draw on the fuse box with everything switched off...no problems.
Alternator checked for possible problems...all ok. In desperation I took the car to a local garage they rechecked everything and couldn't find anything that would drain the battery in such a short time. By chance I was chatting to a chap who is rebuilding an Audi and he told me to isolate the battery case from the body of the car. I followed his advice and surprise surprise problem solved. Strange eh!!!

Ken
Where is your battery located?
The normal position is on the GRP moulded front bulkhead cover. Why would this allow a discharge?
Mike

[ken]

Re: Battery Problems

I used a peace of rubber to insulate it.
My battery is seated on the bulkhead cover and I really do not understand why it has worked but so far so good. Maybe one of our techies could explain it.
Ken

[danny_nelson]

Re: Battery Problems

Down to the little people by the sound of it!! If the car is a Cabrio model ?

[listerjp2]

Re: Battery Problems

Hi

GRP will conduct Electricity if there is some conductive medium on the surface like on saltwater boats.

Dried salt on a boat is highly conductive and can sometimes fool people into believing that their fiber glass boat conducted electricity.

But for fiberglass alone....No, it doesnt conduct electricity.

Adrian

[cameronfurnival]

Re: Battery Problems

That's really weird Ken - Im with Danny on this one...the little people!

[Robert in Cumbria]

Re: Battery Problems

I did a google on this one. My initial reaction was perhaps electrolyte or salt on the outside of the casing creating a path or circuit for the leakage to ground (or chassis).

This is an interesting theory I found which MAY explain the phenomenon. Given the cold weather we are experiencing it may be feasible?

Extract from Wiki Answers: (the question referred to a battery on a concrete floor)

"It actually is based upon temperature-----. Batteries are insulated in a plastic or rubber case, so electricity leaking to the cement is not in the question. Even more so, batteries normally sit in a metal tray in a car. If battery leakage were to occur, it surely would sitting on metal.

The actual cause is temperature difference between the top of the battery and the bottom. The specific gravity of the electrolyte changes with temperature. Therefore the specific gravity of the electrolyte is less at the top of the cell and more at the bottom. As measuring the specific gravity tells the state of charge of the cell, the cell has more of a charge at the top of the cell than the bottom. This causes an internal current drain inside the plastic battery case.


All batteries will discharge no matter where they are sitting when not being used. This is called "Shelf Life". A battery will not be damaged by sitting on a concrete floor versus sitting on wood. You will just have to charge it up to use it. It should be noted that a lead acid battery will eventually sulfate the longer it is discharged. Sulfation is not fully reversible.
People who believe that a battery is ruined by sitting on a concrete floor don't realize that probably the battery was acting up to begin with and was removed from a vehicle because it was going bad. After sitting on a concrete floor for a period of time, they try to charge the battery and find it bad. Therefore the conclusion was that the concrete floor ruined the battery instead of the battery getting plain worn out from usage in a vehicle.

It is all due to temperature and nothing else."

Not sure if rubber is a good thermal insulator? My battery is sat on a piece of 10mm ply, I haven't had any discharge problems so far, it is clamped to the painted chassis with a painted steel clamp bar. The car is in a cold garage, prior to fitting the battery to the car it was sat on a cold tiled floor the air in the room was cold too so there would be no temperature differential to speak of.

[stevejgreen]

Re: Battery Problems

Interesting findings Robert.
Does it suggest that if you have a battery out of a car, it should ideally be stored off of a cold floor, or at least with some thermal insulator between floor and battery, (I am thinking polystyrene though the acid may attack it.)

When garaged my Roadster is constantly on trickle charge (fancy charger that adjusts its output automatically) with the battery in situ.
Never had a problem.

[ruby131]

Re: Battery Problems

My Roadster battery sits in an alloy carrier bolted to the alloy bulkhead with a piece of rubber beneath and behind it. I always disconnect when the car is off the road and touch wood have never had a problem.

[rog8811]

Re: Battery Problems

Hi Ken, just to make my post clear, I seem to have solved the problem by using an isolating terminal, if the car is not going to be used for a week or two I undo the isolator nut so disconnecting the neg side of the battery. It is just a quick, spanner-less way of getting around the problem.

[ken]

Re: Battery Problems

Thanks Rog, it seems I was not the only one with this problem. Very strange solution but it seems to have worked so far.

[chris_cussen]

Re: Battery Problems

I use a battery master switch. It has a removable key so works as an anti theft device too.