Discussion
I know the feeling Jon, and I too am starting to get peed off with it.
I've replaced the battery with a nice beefy one, I've renewed the big fuse holder and put in a midi fuse, I've checked the wiring from alternator to starter motor. The car is always kept in a secure garage so never alarmed but if it's been left 4/5 days when I try to start it and don't catch it on the first turn over the second time it just clicks like it has a flat battery. I did suspect a bad earth but the strap on the chassis looks ok.
I'd really like to get to the bottom of it. Sorry for slight hijack.
I've replaced the battery with a nice beefy one, I've renewed the big fuse holder and put in a midi fuse, I've checked the wiring from alternator to starter motor. The car is always kept in a secure garage so never alarmed but if it's been left 4/5 days when I try to start it and don't catch it on the first turn over the second time it just clicks like it has a flat battery. I did suspect a bad earth but the strap on the chassis looks ok.
I'd really like to get to the bottom of it. Sorry for slight hijack.
The problem could be that the battery is simply not getting charged up enough. I recall Julian64 saying that at idle, the alternator isn't keeping up with even basic demand, so the car is effectively running off the battery. In most cars, the battery is used to start the engine, then the alt takes care of all loads, even at idle. This means the battery is never deeply discharged and can be easily topped up under normal driving conditions.
A deeply discharged battery takes much longer to re-charge and a normal car alternator will not do this, due to the voltage regulator dropping the voltage too soon.
Given the fact that the Cerbera's alternator is not keeping up at low speeds, I wonder if an external controller would help?
http://www.adverc.co.uk/products/products.asp?cat=1
A deeply discharged battery takes much longer to re-charge and a normal car alternator will not do this, due to the voltage regulator dropping the voltage too soon.
Given the fact that the Cerbera's alternator is not keeping up at low speeds, I wonder if an external controller would help?
http://www.adverc.co.uk/products/products.asp?cat=1
volospian said:
I agree. Putting a voltmeter across my battery at idle provides just over 12 volts, and that's with nothing electrical actually running. As soon as you increase revs the voltage jumps up to a healthy 13-14 or so, but at idle it is barely holding it own.
agreed on mine this happens, i go through batteries all the time...alternator is just not charging it....
are there recommended versions that pump out more juice?
dean_ratpac said:
volospian said:
I agree. Putting a voltmeter across my battery at idle provides just over 12 volts, and that's with nothing electrical actually running. As soon as you increase revs the voltage jumps up to a healthy 13-14 or so, but at idle it is barely holding it own.
agreed on mine this happens, i go through batteries all the time...alternator is just not charging it....
are there recommended versions that pump out more juice?
I have a little Suzuki runaround with a tiny battery which I use as an emergency car. It can be left for 12-months and still spin the engine strongly when the key is turned.
I can fully charge the battery on the TVR, leave it in the garage plugged into a solar charger for a few weeks and it won't start. If is use the car daily it always starts.
This has to be a drain problem rather than an alternator problem.
I can fully charge the battery on the TVR, leave it in the garage plugged into a solar charger for a few weeks and it won't start. If is use the car daily it always starts.
This has to be a drain problem rather than an alternator problem.
5yearstobuyatvr said:
I left my interior light switched on for 4 days by mistake,light still on but not a whiff to start her
Mine did this once - I suspect the rocker switch was right on the edge of being on and a door slam triggered it. Only noticed it a couple of days later when I just so happened to peer outside at the Cerb late one night last summer when it was dark. Worth checking - as is the boot one. You don't have to climb in the boot by the way(!) just operate the switch on the left hand side by the strut to make sure it goes out.Jon
If it's in the garage then fitting a race style battery switch will stop it draining.
My friend has one on his GT40 rep and it does not affect the imobiliser operation, so should be ok on our Cerbs?
What sort of charger do you have?
Optimate III seems to be good as it constantly checks the state of the battery and can recover a deep discharged one, but if there is any drain on the system it can get confused!
So best with these to disconnect the battery from any possible drain.
Do the interior lights have a "soft" shut off, or are they all through the switch?
Good Luck!
Steve
Forgot to add - I believe that the key switch will issolate all th electrics including the alarm if switched off. Might be worth turning if off while on charge and not being used.
If it's in the garage then fitting a race style battery switch will stop it draining.
My friend has one on his GT40 rep and it does not affect the imobiliser operation, so should be ok on our Cerbs?
What sort of charger do you have?
Optimate III seems to be good as it constantly checks the state of the battery and can recover a deep discharged one, but if there is any drain on the system it can get confused!
So best with these to disconnect the battery from any possible drain.
Do the interior lights have a "soft" shut off, or are they all through the switch?
Good Luck!
Steve
Forgot to add - I believe that the key switch will issolate all th electrics including the alarm if switched off. Might be worth turning if off while on charge and not being used.
Edited by Steve E on Thursday 3rd April 22:11
There is no mains supply to the garage so the charger is just a single solar panel.
All interior lights are turned off.
I'd love to fit a battery switch but where is the best place to install it. There are three cables attached to the battery. One I assume goes to the starter, one to the fuse box and the third one (with a fuse) to either the radio or alarm (I'm not sure)? Would I need to switch all three?
It's difficult to lift the bonnet in my garage so could I install a switch in the cabin? Is the cable to the fuse box easily accessible as it passes through the car?
All interior lights are turned off.
I'd love to fit a battery switch but where is the best place to install it. There are three cables attached to the battery. One I assume goes to the starter, one to the fuse box and the third one (with a fuse) to either the radio or alarm (I'm not sure)? Would I need to switch all three?
It's difficult to lift the bonnet in my garage so could I install a switch in the cabin? Is the cable to the fuse box easily accessible as it passes through the car?
Jon
How many watts/millamps does you solar cell put out?
It will of course only work in day light and if there is any drain on the battery it might just not be enough to catch up and keep it charged in winter?
I've not looked myself, but it would probably be best to fit the battery isolator switch as close to the battery as possible, under the bonnet on a strong bracket.
All the wires on the positive would need to be fitted to the isolated side of the switch such that the battery is completly isolated.
You would only use it when in the garage and on the solar cell.
So an alternative would be a more modern "Lever Clamp" type battery post connector, which can just be flipped up and pulled off the post of the battery. Any auto electrical shop should be able to fit this for you very quickly.
But have you tried turning the key off yet? It says in the hand book it isolates the ignition and aalrm system.
If your not bothered about not having the alarm working, this may cure you problems if the alternator is not leaking amps away.
Steve
How many watts/millamps does you solar cell put out?
It will of course only work in day light and if there is any drain on the battery it might just not be enough to catch up and keep it charged in winter?
I've not looked myself, but it would probably be best to fit the battery isolator switch as close to the battery as possible, under the bonnet on a strong bracket.
All the wires on the positive would need to be fitted to the isolated side of the switch such that the battery is completly isolated.
You would only use it when in the garage and on the solar cell.
So an alternative would be a more modern "Lever Clamp" type battery post connector, which can just be flipped up and pulled off the post of the battery. Any auto electrical shop should be able to fit this for you very quickly.
But have you tried turning the key off yet? It says in the hand book it isolates the ignition and aalrm system.
If your not bothered about not having the alarm working, this may cure you problems if the alternator is not leaking amps away.
Steve
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