Do I need a new battery or alternator?

baggy798 · Aug 28th, 2012, 22:28

Hello,

The car wouldn't start a few days ago but I got a jump start and its been ok since then, perhaps only very slightly slower to turn over.

So I put a volt meter on the battery today and it read 11.9v. (driven a few miles/hot engine)

Started the car and the reading jumped around a bit before settling on 13.6v.

Then I put the lights on and the heater on full and it read 13.2v, turned them off and it went up to 13.4v.

The first reading suggests it is the battery, but I thought when the engine is running it should be 14.4v?

barkster1971 · Aug 28th, 2012, 22:46

Mine was getting tired and anything below 12.5 V it wouldn't start. I put a bigger battery on and getting well over 14V when the car's running. I had a couple of issues with my amp sucking current. Check to see if there's any draw (mA) across the battery terminals too!
My new battery has 750 CCA, starts alright now!

DEWFPO · Aug 29th, 2012, 03:36

Volvo's charging system on these vehicles typically run at 13.7 volts a few minutes after starting with a good battery. !4.4 volts is where most other manufacturers charging systems seem to be at, but not Volvo's.

It sounds like your battery is ready for a changeout.

DEWFPO

ian2000t · Aug 29th, 2012, 13:19

If your battery is getting on it will also require more charge from the alternator - like putting the lights on, so you will likely see lower voltage even charging.

My theory has always been if it jumps up a few volts when the alternator is running, the alternator is ok.

sandstrom · Sep 4th, 2012, 23:11

it sounds like you would need to replace the battery
on both the battery and the generator was broken, it would not even your car go.
if the generator was broken so your car would only go for a while until the battery was over then the engine would stop.

Ifitantacatitsadog · Sep 6th, 2012, 03:48

If you put a calcium/gel battery in the lower restance will give you around 14.2-3 but on a lead your only looking for 13.6-8 put every thing you can find on and hold the revs at 1800rpm ish this will show you how strong your alt is but it's your battrie that is the problem

Aug 28th, 2012, 22:28	#1
baggy798 🤍💙💗 Last Online: Today 12:51 Join Date: Mar 2006 Location: Lichfield	Do I need a new battery or alternator? Hello, The car wouldn't start a few days ago but I got a jump start and its been ok since then, perhaps only very slightly slower to turn over. So I put a volt meter on the battery today and it read 11.9v. (driven a few miles/hot engine) Started the car and the reading jumped around a bit before settling on 13.6v. Then I put the lights on and the heater on full and it read 13.2v, turned them off and it went up to 13.4v. The first reading suggests it is the battery, but I thought when the engine is running it should be 14.4v?

Aug 28th, 2012, 22:46	#2
barkster1971 VOC Member Last Online: May 12th, 2024 14:32 Join Date: Jun 2009 Location: Swineshead/Salford	low Mine was getting tired and anything below 12.5 V it wouldn't start. I put a bigger battery on and getting well over 14V when the car's running. I had a couple of issues with my amp sucking current. Check to see if there's any draw (mA) across the battery terminals too! My new battery has 750 CCA, starts alright now! __________________ new engine! new car!

Aug 29th, 2012, 03:36	#3
DEWFPO 960 & S90 owner Last Online: Oct 27th, 2014 18:59 Join Date: Mar 2012 Location: "High in the Rockies"	Volvo's charging system on these vehicles typically run at 13.7 volts a few minutes after starting with a good battery. !4.4 volts is where most other manufacturers charging systems seem to be at, but not Volvo's. It sounds like your battery is ready for a changeout. DEWFPO __________________ 1995 964, White 1998 S90, Coral Red Metallic

Aug 29th, 2012, 13:19	#4
ian2000t Premier Member Last Online: Oct 21st, 2023 20:25 Join Date: Dec 2008 Location: Halesowen	If your battery is getting on it will also require more charge from the alternator - like putting the lights on, so you will likely see lower voltage even charging. My theory has always been if it jumps up a few volts when the alternator is running, the alternator is ok. __________________ 1990 Volvo 760 GLE D24TIC ZF22 - 16psi, more fuel, Monark 293 nozzles, 40mm lower, Bilstein TCs, 24/19 ARBs, full Polybushed front, H&R spacers, 17" Titans. Running Veg oil/petrol mix. Past: 1988 Volvo 740 B230E M46, 1991 Volvo 940 B230FB M47

Sep 4th, 2012, 23:11	#5
sandstrom New Member Last Online: Sep 20th, 2012 21:04 Join Date: Aug 2012 Location: sundsvall	it sounds like you would need to replace the battery on both the battery and the generator was broken, it would not even your car go. if the generator was broken so your car would only go for a while until the battery was over then the engine would stop.

Sep 6th, 2012, 03:48	#6
Ifitantacatitsadog New Member Last Online: Oct 9th, 2012 19:52 Join Date: Sep 2012 Location: Dunedin	If you put a calcium/gel battery in the lower restance will give you around 14.2-3 but on a lead your only looking for 13.6-8 put every thing you can find on and hold the revs at 1800rpm ish this will show you how strong your alt is but it's your battrie that is the problem

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