Why do they kill batteries?

[No1bassmonkey]

So its that time of year again for the yearly battery change, such an annoying job especially when you cant get the door open until the new battery is connected up. I use the car quite infrequently, so got an accumate conditioner, initially it seamed to work, but in the last 3 years I have got through 4 batteries, (thank god Halfrauds replace them under warranty each time) does everyone have the same experiance with batteries getting eaten or is it just me?

[TVR keith]

My battery just died, think it's the original, not too bad for 6 years old. But when I got it out and most of the cells were bone dry I couldn't help wondering how long it might have lasted if I had been able to keep it topped up.But who wants to go through such a pantomine to do so?
The replacement is maintenance free, hopefully that will last OK.
I also insulated the metal heater pipes as detailed in The Chimaera pages, so a bit less heat should help

Edited by TVR keith on Friday 17th November 14:28

Edited by TVR keith on Friday 17th November 14:28

[Flintstone]

Why not just use the car regularly and avoid such problems?

Frankly I can't imagine having one and leaving it idle.

[Ribol]

My car is X reg, I changed the original battery last year, it did not fail, just thought I would get in first so to speak. This car has never failed to start first time every time even when left unused for over a month.

These cars are so unreliable

[hut49]

No1bassmonkey said:

in the last 3 years I have got through 4 batteries

They certainly don't all do that - must be a fault somewhere. I change my battery ever 3rd annual service - their lifetime expectation is 4 years but for the tiddly cost of a new one (vis a vis the other running costs) it's just not worth the hassle of finding out on the first frosty morning that it just doesn't have what it takes to do the job.

[Cider Andy]

Your car certainly should not be using four batteries in three years. As they have been replaced under warranty it would suggest that they were faulty, but that's quite a coincidence.

The alarm/immobiliser systems are often blamed for quickly discharging the battery. This may be the case, but there are other cars where this is not the case. My particular car was left outside for three weeks last winter without a charger connected and it started without problems. There's nothing in the history to say the battery has been changed and the car was six years old at that time.

What went wrong with the batteries that were changed?

[zumbruk]

The reasons that "weekend" cars gallop through batteries are;

- A lot of modern cars still draw quite a lot of current, even when they're switched off. The alarm, and sometimes the EMU are left powered on, even when the ignition is off. My 3-door Sierra Cosworth drew 200mA, even when the ignition was off, and would completely flatten a battery in a couple of weeks. I've not measured the Chim, so I don't know what that does...

- Car batteries are not designed to be deep discharged. Once they have been, they're never the same again, and will not retain a charge. Before I got a battery conditioner, I used to get 8 months out of a battery, if I was lucky. It was usually going away on holiday that killed them off completely - the car stood for 2 or 3 weeks, and when we got home the battery was stone dead.

Combine these two things and it's no wonder they don't last. The answer is to get a conditioner and use it religiously, and if you're going to be away and don't like leaving the conditioner on, disconnect the battery.

[steve-v8s]

The key culprit (certainly on the Griff) to quickly discharging the battery is the door not correctly connecting with the door switch. Even if the internal lights are switched off the light relay is still powered which will discharge the battery in a few days. The alarm and immobiliser also draw a fair current, which doesn’t help. It is worth checking that nothing else is drawing excess current in standby, sometimes the alternator diodes can become leaky and drain the power.

The real problem is that modern batteries cope very poorly if left for any time in a discharged state. The cells “Sulphate” this means that they build up coating that effectively cuts down the surface area between the electrode and the electrolyte. This has the effect of reducing the capacity, so next time the cell is charged it will become “full” and stop charging more quickly but become flat more quickly and start to sulphate again and very soon it has insufficient capacity to start the car. This is more of a problem where cars are repeatedly left for fairly long periods without being driven. If the car is repeatedly left for a week or so and not used the only real cure is to plug in a trickle charger.

[poorpeet]

Anyone thought of moving the battery to the boot?
I know a few Griffith owners have done it.

[Steve42]

Sounds like a fault mate. Had mine from new - 5 years - and just changed it to stay ahead of the game. Usually left standing for up to 2 weeks at a time, then gets a long run

[colinrob]

Only used mine at weekends and did not use it in the winter for about 3 months always plugged in my acumate battery conditioner via the cigarette lighter never had any problems with battery over 3 years

[blackspider]

You need to have the battery drain checked.
An ideal battery drain is about 30 milliamps.If it sits above 100ma it will drain within a month,if you keep draining the battery to the point of dead flat the active material in the cells will solidify and kills the cell making the batt. useless-most TVR's seem to sit at around 150ma-Various causes from alarms,stereo's,central locking,poor earth points etc

[ed]

If it goes completely flat does that mean it is completely screwed?

[blackspider]

That just depends on how long its been dead flat 4 and how mant times its been in that state.
The only way to check it is to slow charge the battery for as long as possible-24hours+
If it thas the screw caps on top then undo them(wear rubber gloves to protect your fingers from acid)and with the battery still on charge you should see each cell lightly bubbling(wear glasses to protect your eyes)If they all do then this is a good sign.If one doesnt then its dead.
Or after its been on charge take to someone with a battery drop tester-this puts a load onto the battery and it should maintain a high amp output.

[ed]

This is the first time it has been totally flat. Tried an Accumate while it was almost dead but it may have gone a liitle far for that to have an effect. Will jump it tomorrow and take it for a really long drive to put some charge back into it. Hoping that will do the job.

[Ribol]

Charging a dead flat battery is not a problem if you have a decent charger.
If you don't have a decent charger, connecting a second battery(one with some charge in it) in parallel will help to get the flat one going. When the flat one has taken some charge, take the second battery off and charge the problem battery for a day.
You will not charge a flat battery properly by driving the car - fact.

[zumbruk]

Ribol said:

Charging a dead flat battery is not a problem if you have a decent charger.

Quite so. The problem is that the battery will not retain the charge, especially if it's been allowed to go completely flat a couple of times. You can charge it all you like, but 72 hrs later it'll be stone dead again.

That's why they sell "recreational" (deep discharge) batteries for caravans, etc., which can be allowed to go flat. Car batteries are not designed to do this; they're designed to deliver huge currents for a short time and be immediately recharged.

[No1bassmonkey]

First of all thanks everyone for all of the help, I will try and answer all your points and then tell you how far I have got with it all.

Flintstone - I would use it regularly, but working just 10 minutes walk from my house it would cause more dammage to use it each day than not, It does get used at weekends but with less than a mile to work from what I have read on the forums this would cause more dammage than not using it.

Ribol - I wasnt suggesting that they are unreliable, although I have been bitten on more than one occasion by the hot start issue, it will be fixed this weekend but it is annoying.

Andy - In all cases the batteries have been completely flat, Halfrauds have diagnosed them all being just kaput and not really given much more detail than this. The car is fitted with the standard Meta? alarm, and then an aftermarket clifford one, unfortunately not long after getting it the clifford stopped working trying to get someone to fix it is hard and I just havent had the time yet to go down and see Carl that everyone recomends for sorting alarm issues.

Steve - On the money from you, gold star, it appears at some point the rubber bung that makes connection with the switch has come off, this will be replaced at the weekend and will see if that helps improve things.

Poorpet - Have considered putting a split charge system in to be honest with all of the problems that I have been having recently.

BlackSpider - thanks for the suggestions, I will check the draw that the battery has on it when at rest, if above what you have suggested as reasonable levels I might consider a full cut off switch.

Dont get me wrong guys, the car is great and I LOVE the sound, just always seams to be a little niggle, guess thats half the fun though.

Thanks for everyones help.

[rooster]

mine is superb, had it 4 and a half years, doesnt die because I keep the optmate on when not in use. My Ka is far less reliable than the chim!

[leadfootlydon]

When I first got the car, I was surprised to find it could not be left a week without the battery going flat.

I has been no trouble at all since I bought the Optimate. (Still on same battery).