battery dies on starting with headslights on

[mitchelltjohn]

I seem to have a curious intermittant battery / electrical fault. My battery seems healthy, reading midway on above on Voltmeter at all times. However, on three occasions in past 2 weeks, when I have tried to start car with headlights on teh battery have drained almost instantly to about 8volts with not enough power to hardling light the dash lights on door courtesy lights. I have to jump start or charge teh battery to get the car going again. However, the fault does not occur everytime I try to start with headlights on...

Has anyone else had a simialr experience? Any ideas what might be wrong and how to trace such faults?

1979 FHC pageant blue
1981 DHC triton green

[FI Spyder]

Battery on the way out. Usually starts with a bad cell. Although it may read 12 volts, a cell and perhaps the rest to a lesser degree will not "hold a charge", (have the amperage to turn over the engine )it's biggest load. You can take it to a garage etc. where they can give it a load test where they put it under load then measure the voltage. Basically you get what you pay for in battery (mark up not withstanding) and price/quality depending on size of plates, physical durability by plate construction and depth of well at bottom. With use, parts of the plate flake off and if the well at bottom of battery is not deep enough it will eventually short out the cell sooner than later.

- - -TR7 Spider - - - 1978 Spitfire- - - - 1976 Spitfire - - 1988 Tercel 4X4 - Kali on Integra - 1991 Integra - Yellow TCT

[windy one]

<blockquote id="quote"><font size="1" face="Century Gothic, Verdana, Arial, Helvetica" id="quote">quote:<hr height="1" noshade id="quote"><i>Originally posted by FI Spyder</i>

Battery on the way out. Usually starts with a bad cell. Although it may read 12 volts, a cell and perhaps the rest to a lesser degree will not "hold a charge", <hr height="1" noshade id="quote"></font id="quote"></blockquote id="quote">

+1 !! How old is said battery, too? There are cheap testers you can buy to verify if a cell is bad. But like Spydey says....sounds like a cell going bad. [:(]

Johnny

[Hasbeen]

The battery in my S2000 would not start the car once, after a 35Km drive, & a 5 minute stop for fuel.

After a jump start then, it behaved perfectly for a couple of months, before repeating the trick.

A new battery fixed it, & the local auto electrician said it had one dying cell.

Spyder in Oz you don't get what you pay for, unfortunately with batteries. The local smarties make just one battery, with different names.

The cheap ones have a 2 year warranty, but others have a 3 or 4 year warranty. The higher price for the longer warranty is actually just an insurance like scheme. The companies take the chance their cheep batteries will go 4 years, & the extra they get for the "better" long warranty battery, covers the replacement of those few that don't.

Cunning aren't they!

Hasbeen

[TheBozz]

Hi Mitchelltjohn I had a similar problem when we had a cold spell the TR7 wouldn't start so I would take the battery out attach it to the battery charger to charge and within 3 minutes the ready and maintaining light would come on? So I would fit it back in the car and it would be fine for a few days then sure enough the same thing would happen again. I've just replaced the battery and WOW what a difference the car purrs and I wish I had done this a few months back. I did buy the new battery off a popular auction site but Halfords offer the same one at the same price online around £55.00 it's a no brainer really.

TheBozz
1980 TR7 2.0 DHC

[spanner]

If you get a Halfords trade card batteries are one area that they give a decent discount on, the cards canbe issued at "managers discretion" if he/she knows anything re Triu mphs they should be giving them out like sweeties.
atb
Mike

Near Penrith and the Lake District