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Need to replace the battery?

Today starting up the wife's '95 Disco 1, it cranked awfully slow. First time it's ever done that since we've had the car (didn't do it yesterday?!) so I automatically assume the battery needs to be replaced since I have no idea how old it is.

After we got home I checked it with the voltmeter and found 11.38 volts without the engine running. Pretty sure it should be 12.6-12.8V while sitting, right (for a healthy battery)? Checked it again with the V8 idling and found 12.36 volts...should be closer to 14V with the engine running right?

I figure from my findings, the increased voltage at idle shows that the charging system is working properly, and I have no dash lights, so I'm still thinking it's the battery.

What brands are good/which to avoid and how much should I expect to spend? Thanks

Reply to
Anthony
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Probably right, but the problem could be a sick alternator - or loose belt - that is giving some charge but not full amount. If the battery is as high as 11.38 with no charge I would expect it to rise higher if the alternator was charging properly. If the battery was sick enough to have a charging voltage that low, I would expect its rest voltage to be lower. This is all speculative, but try, for example, the voltage with the engine at a fast idle, particularly with a fast idle and headlights on or off - should be little difference if the alternator is working properly.

JD

Reply to
JD

Anthony uttered summat worrerz funny about:

Have you / can you check the fluid in each cell? one may be dry.

Also take it to a reputable battery dealer and have it drop tested - not a krick frit frigger. I normally have to get my local battery dude in a headlock before he would sell me a battery.

Get summat with a 3 or 4 year return on it - that way you'll know you are not pouring money down the drain.

Lee D

Reply to
Lee_D

In message , Anthony writes

I would expect about 13.8V+ with engine running. Could be an alternator problem

Reply to
hugh

Sounds like an alternator problem to me too.

Colin

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Reply to
Colin Reed

Alternator? Rats. That's not what I wanted to hear. Can I check the voltage directly at the alt? What should I find?

Reply to
Anthony

there isnt much price difference between buying an alternator and a battery so it aint the end of the world! ;)

Reply to
Tom Woods

Don't bother - it'll be the same as it is at the battery.

Fist step tho - check the alternator belt is tight - if it slips it won't charge.

Reply to
EMB

Good news! Replaced the battery. Had 12.8 volts even on the new battery without the engine running. Started the engine had and 14.01 volts at cold idle. So that means the charging system is healthy!

I guess the old battery was so sick it was affecting the charging capability of the alternator. The serpentine belt has something like

20K miles on it, replaced 3 years ago so I think it's still OK for a while. It is good and tight and not slipping.

So that problem seems to be solved for now...I'll check the batt with the engine running at hot idle sometime later this week and see if its any different, since today's check was at cold idle.

Reply to
Anthony

At idle, headlights and heater blower on, what voltage shows?

Reply to
EMB

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