Battery advice
Discussion
Yesterday I recovered a friend's TVR 350i (hardtop 2+2, which I think is quite rare) which has some starting problems.
The battery seems to me to be a bit on the light side - 70AH/315 - on the basis that I've got the same battery in a 4-cyl 1960's Alfa. Even fully charged, it turns over quite slowly and if it doesn't catch quickly, I guess it's flooding. The battery itself is OK.
Can anyone suggest what we should be looking for in terms of battery spec?
The battery seems to me to be a bit on the light side - 70AH/315 - on the basis that I've got the same battery in a 4-cyl 1960's Alfa. Even fully charged, it turns over quite slowly and if it doesn't catch quickly, I guess it's flooding. The battery itself is OK.
Can anyone suggest what we should be looking for in terms of battery spec?
Yeah, *very* light.
A 315 CCA is typically for a small 4 cyl engine....
The 2.8 cologne engine should have a battery of around 400CCA, and I think the V8 should have around 500CCA.
The second number, CCA is Cold Cranking Amps and it tells you what the battery can deliver to crank the engine.
I think you need a DIN55 battery or equivalent (or check with battery supplier for a Rover V8 requirement)
DIN55 is 480 CCA.
Or the other way is the biggest battery that will fit in the space.....
A 315 CCA is typically for a small 4 cyl engine....
The 2.8 cologne engine should have a battery of around 400CCA, and I think the V8 should have around 500CCA.
The second number, CCA is Cold Cranking Amps and it tells you what the battery can deliver to crank the engine.
I think you need a DIN55 battery or equivalent (or check with battery supplier for a Rover V8 requirement)
DIN55 is 480 CCA.
Or the other way is the biggest battery that will fit in the space.....
Edited by RCK974X on Monday 25th April 10:36
RCK974X said:
The other way is the biggest battery that will fit in the space.....
Thats good advice ...Although the gaps can differ somewhat...You do really need a good kick for a V8..500-650 is good...Measure the gap you have...Make sure you measure the whole area as my 280i tapered in making finding a battery very difficult.sunbeam alpine said:
Even fully charged, it turns over quite slowly and if it doesn't catch quickly, (...) The battery itself is OK.
It could also indicate that the starter motor is about to give up, if everything else electrical works properly, and the battery is in good nick - try cranking with the bonnet open and sniff for the telltale whiff of a dying electric motor Hayduke said:
sunbeam alpine said:
Even fully charged, it turns over quite slowly and if it doesn't catch quickly, (...) The battery itself is OK.
It could also indicate that the starter motor is about to give up, if everything else electrical works properly, and the battery is in good nick - try cranking with the bonnet open and sniff for the telltale whiff of a dying electric motor 300bhp/ton said:
If the battery is too small, even in good condition it won't be able to delivery the amp draw under load, i.e. when cranking, so will likely crank slower.
yes, that's true, the thread IS about battery advice, all good points about undersized batteries and going with the most powerful battery that fits. But, I assume the smaller battery used to work for cranking the car - and if its fully charged and otherwise not defective, and the temperature in his garage hasn't dipped dramatically - then after checking all the wiring to the starter, the starter is next down the line. They are somewhat notorious for failure. PERHAPS not so quick to blame the battery - the cold cranking amps are in most demand for low temps or high compression ratios ...
PieterLOL said:
Owner of the car here :-)
Don't think there's an issue with the starter, car always seemed to start fine when battery fully charged or slightly assisted. When it doesn't start, I also see the voltage meter drop slightly - Could make sense if the battery is indeed just too small.
Check the earths and make sure they are clean and are making contact...Especially the one on the N/S inner rocker cover....There should also be one on the N/S front suspension turret...Also check the tension of your alternator belt...especially if you are going to replace the battery...It probably is just a knackered battery...Don't think there's an issue with the starter, car always seemed to start fine when battery fully charged or slightly assisted. When it doesn't start, I also see the voltage meter drop slightly - Could make sense if the battery is indeed just too small.
All good advice.
Battery vs. starter.
Small battery MIGHT be OK, you are correct, but it's still too small for comfort.
Batteries are very temperature dependent, and as they age, their ability to deliver high current for the starter drops off, and low temps makes this effect worse. So if it was a cold morning it may have been just that bit too much .....
Yes voltage will drop when cranking - if it drops a LOT (like below 8 volts) then battery is probably to blame.
Batteries can also drop a cell quickly, almost overnight, and this results in slow/no cranking, but its voltage will drop, so it's obvious with a test meter. You could also take the battery to a shop and have it tested.
On the more general question "slow cranking" I still would have pointed to the battery but also recommended you check the main cables, especially the earth/engine block connection, as they can quietly corrode...and if any lumps in the cable (= broken strands).
Yes, it could also be the starter, they can burn the motor brushes and a range of other things.
Have you got jump leads ? that's an easy way to check - use a known good battery and if it cranks fine, then you know it's the battery.
Battery vs. starter.
Small battery MIGHT be OK, you are correct, but it's still too small for comfort.
Batteries are very temperature dependent, and as they age, their ability to deliver high current for the starter drops off, and low temps makes this effect worse. So if it was a cold morning it may have been just that bit too much .....
Yes voltage will drop when cranking - if it drops a LOT (like below 8 volts) then battery is probably to blame.
Batteries can also drop a cell quickly, almost overnight, and this results in slow/no cranking, but its voltage will drop, so it's obvious with a test meter. You could also take the battery to a shop and have it tested.
On the more general question "slow cranking" I still would have pointed to the battery but also recommended you check the main cables, especially the earth/engine block connection, as they can quietly corrode...and if any lumps in the cable (= broken strands).
Yes, it could also be the starter, they can burn the motor brushes and a range of other things.
Have you got jump leads ? that's an easy way to check - use a known good battery and if it cranks fine, then you know it's the battery.
Edited by RCK974X on Monday 25th April 21:31
OK, on the grounds that the only stupid question is the one you don't ask - here goes!
The only good battery we have lying around is from a New Holland tractor, with 1000 CCA! It fits! But can you put too much current through the starter?
Just want to test to make sure it's definitely the battery.
The only good battery we have lying around is from a New Holland tractor, with 1000 CCA! It fits! But can you put too much current through the starter?
Just want to test to make sure it's definitely the battery.
Had an issue where I had flooded my plugs and it would not start. Put in the spares and it fired up. The flooded plugs needed a good clean and bake before they would have it.
I hasten to add all the ingredients were there for the bang, that was all checked out first.
At the time the battery was a bit long in the tooth and was not turning over well. The one I have now, well, that spins it up a treat but I keep a ctek on the battery to keep it topped up.
I hasten to add all the ingredients were there for the bang, that was all checked out first.
At the time the battery was a bit long in the tooth and was not turning over well. The one I have now, well, that spins it up a treat but I keep a ctek on the battery to keep it topped up.
sunbeam alpine said:
Update - still doesn't start! Cranks very fast with the new battery, but doesn't fire. Plugs are wet, so fuel is getting through, and we have a strong spark, so what's going wrong?
If there's fuel, and spark at the right timing (???) then could be flooded. Might be worth double checking that at TDC (remember TDC comes around twice on the pulley so ensure it is correct) the rotor arm is lined up with number 1 plug. If so then get the plugs all out and dry them thoroughly.If you have connected a 1000CCA battery (12v) with jump leads and it turns over nice and quick, the good news is that you know that the starter motor and its wiring is fine, and it is the battery. So that's one tick.
(Yeah - you can connect any size battery for testing as long as it's 12v)
If you have spent ages cranking (slowly) to get car to start, then yep, plugs could be wet/covered in crap/etc. Probably worth cleaning them
and you can check there is fuel on them whilst you are doing this. (Already done - from your post)
You have fuel and sparks - which is good !
May be worth checking inside of dizzy cap is clean etc - where did you check the spark ? One of the plugs is best as it checks all the bits in between...
(Yeah - you can connect any size battery for testing as long as it's 12v)
If you have spent ages cranking (slowly) to get car to start, then yep, plugs could be wet/covered in crap/etc. Probably worth cleaning them
and you can check there is fuel on them whilst you are doing this. (Already done - from your post)
You have fuel and sparks - which is good !
May be worth checking inside of dizzy cap is clean etc - where did you check the spark ? One of the plugs is best as it checks all the bits in between...
Edited by RCK974X on Friday 29th April 20:28
The third element - Air?
Metering plate move ok? Remove the air filter and the metering head (rubber) cap and push it up from the bottom side. (Or grab the center nut with plyers and pull up.) Should move smoothly up about 2 inches and when released go down. This is probably not the problem because you are apparently getting fuel (wet plugs) but make sure the plate is clean, I've had problems with oil building up on mine.
While off, make sure the rubber metering head cap isn't cracked. Ditto the big air intake hose. Might want to check that the throttle valve is moving smoothly. And the other air hoses look OK. When you put it back on, make sure the air intake hose/metering cap connection is tight.
I used some starting ether which got things firing enough to start the whole system running. Although it took 5-10 tries before it really caught and continuously ran - albeit at a 3K 'idle'. But it got me to the point I could get the engine warmed up and start making meaningful adjustments.
Also I had 2-3 'backfires' that popped the silicone intake hose off the metering head cap.
There is a long thread from last month with all the good suggestion for getting my 280i to fire up. Grady
Metering plate move ok? Remove the air filter and the metering head (rubber) cap and push it up from the bottom side. (Or grab the center nut with plyers and pull up.) Should move smoothly up about 2 inches and when released go down. This is probably not the problem because you are apparently getting fuel (wet plugs) but make sure the plate is clean, I've had problems with oil building up on mine.
While off, make sure the rubber metering head cap isn't cracked. Ditto the big air intake hose. Might want to check that the throttle valve is moving smoothly. And the other air hoses look OK. When you put it back on, make sure the air intake hose/metering cap connection is tight.
I used some starting ether which got things firing enough to start the whole system running. Although it took 5-10 tries before it really caught and continuously ran - albeit at a 3K 'idle'. But it got me to the point I could get the engine warmed up and start making meaningful adjustments.
Also I had 2-3 'backfires' that popped the silicone intake hose off the metering head cap.
There is a long thread from last month with all the good suggestion for getting my 280i to fire up. Grady
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