Electric Solution
Electric Solution
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AL 123

Original Poster:

201 posts

219 months

Monday 6th July 2009
quotequote all
I've had the cerb for about 10 months now & love it!

When i got it the previous owner explained to me that they leak electrically & give it 7 - 10 days & the battery will go flat. (my first TVR so this sounded ridiculous) anyway, this is exactly what it does, hence i have a charger & use that as & when.

My question really is has anyone got a solution to this, other cars generally don't do this, it drives me mad... the will it/wont it start feeling!!

grahamn

1,777 posts

264 months

Monday 6th July 2009
quotequote all
New battery

AL 123

Original Poster:

201 posts

219 months

Monday 6th July 2009
quotequote all
grahamn said:
New battery
Getting one.

How long will it last if not driven without going flat?? Was i being fed a line ..... "leak electrically"....?

julian64

14,325 posts

284 months

Monday 6th July 2009
quotequote all
you can't really ask the question without some information.

Get an ammeter and with the ignition off release the negative terminal from the battery. (actually it matters not which one and on the Cerb the + might be easier.

put your meter between the lead and the battery terminal.

Assuming you have done this right the ammeter should be showing a current less than 100mA.

Anything over 200mA and I would get a friend to start pulling fuses till the value suddenly drops.

Hopefully you'll find out what the current draw is.

On a stationary cerb with the key out of the ignition the only thing that should be taking current is the alarm, and it takes only a few mA.

feed us this info and a fuse chart should tell us where your current is going.

However if your mA are below 100 and your battery is still dying in a couple of days, dump the battery smile

AL 123

Original Poster:

201 posts

219 months

Monday 6th July 2009
quotequote all
julian64 said:
you can't really ask the question without some information.

Get an ammeter and with the ignition off release the negative terminal from the battery. (actually it matters not which one and on the Cerb the + might be easier.

put your meter between the lead and the battery terminal.

Assuming you have done this right the ammeter should be showing a current less than 100mA.

Anything over 200mA and I would get a friend to start pulling fuses till the value suddenly drops.

Hopefully you'll find out what the current draw is.

On a stationary cerb with the key out of the ignition the only thing that should be taking current is the alarm, and it takes only a few mA.

feed us this info and a fuse chart should tell us where your current is going.

However if your mA are below 100 and your battery is still dying in a couple of days, dump the battery smile
Thanks for the advice, i'll defo try this!

It needs a new battery now anyway as its not even charging very well.

However, its always done this, but i do keep the key in all the time, is this a no no??

Byker28i

91,956 posts

247 months

Monday 6th July 2009
quotequote all
The only usage is on the alarm system, but then the alarm system on my motorbike flattens the battery in just over two weeks, so that's probably about right for the car. I robbed the optimate from the bike when I bought the cerbera and so it's always on it when it's in the garage.

high52kojak

505 posts

227 months

Monday 6th July 2009
quotequote all
Mine goes flat in about three weeks without the alarm being on! New battery as well and it made no difference, I may try the ammeter thing

SimonKD

1,387 posts

261 months

Monday 6th July 2009
quotequote all
julian64 said:
you can't really ask the question without some information.

Get an ammeter and with the ignition off release the negative terminal from the battery. (actually it matters not which one and on the Cerb the + might be easier.

put your meter between the lead and the battery terminal.

Assuming you have done this right the ammeter should be showing a current less than 100mA.

Anything over 200mA and I would get a friend to start pulling fuses till the value suddenly drops.

Hopefully you'll find out what the current draw is.

On a stationary cerb with the key out of the ignition the only thing that should be taking current is the alarm, and it takes only a few mA.

feed us this info and a fuse chart should tell us where your current is going.

However if your mA are below 100 and your battery is still dying in a couple of days, dump the battery smile
Wouldn't the clock also draw current, small though it may be?

regards
Simon



Edited by SimonKD on Monday 6th July 19:10


Edited by SimonKD on Monday 6th July 19:11

jonbarrett

800 posts

232 months

Monday 6th July 2009
quotequote all
Replacing my 100A fuse sorted the problem. It was cracked and, I assume, leading to poor charging. Since replacing it it charges like a good'n, holds its charge and fires up big time. Worth a look.

AL 123

Original Poster:

201 posts

219 months

Monday 6th July 2009
quotequote all
jonbarrett said:
Replacing my 100A fuse sorted the problem. It was cracked and, I assume, leading to poor charging. Since replacing it it charges like a good'n, holds its charge and fires up big time. Worth a look.
Nice one, i'll look at this as well.

Would be good to beable to feel you could leave em for a good while & know they were gonna start, like taking it to the airport & leaving it for a couple of weeks....... you wouldn't even be able to get in mine! Imagine that at 4am.... ahhhhh.

Storer

5,024 posts

245 months

Tuesday 7th July 2009
quotequote all
I had a similar problem. Changed my battery to an Optima Red Top RT S 4.2 (tight fit but OK when I cut the handle off) and not had a problem since. Car tends not to be left un-driven for more than 10 days but I never need to charge it now.

FarmyardPants

4,379 posts

248 months

Tuesday 7th July 2009
quotequote all
In my case it was an amp in the boot wired to be live 24/7. Putting a relay in, triggered by the head unit, solved that problem.

If you have an optimate it can give you a good idea how well your charging circuit is working - it should take less than half an hour or so for the LED to turn green after a good drive. Mine used to take hours, new big fuse (sanded to remove oxide and cleaned up terminals etc) brought charge time down to a few minutes. Starts fine after a week, but generally put it on the optimate so don't know how long it would last. The alarm/immob uses power even when the car is unlocked - it must be powered to receive a signal from the blipper.

VPower

3,598 posts

224 months

Tuesday 7th July 2009
quotequote all
One other thing that might take current is the interiour lights.

They dim down to off, rather than switching off.

I turn all three of mine to the off position, and the Optimate goes green very quickly.

Might be worth trying if you do an AMP test on the live from battery?

AL 123

Original Poster:

201 posts

219 months

Tuesday 7th July 2009
quotequote all
VPower said:
One other thing that might take current is the interiour lights.

They dim down to off, rather than switching off.

I turn all three of mine to the off position, and the Optimate goes green very quickly.

Might be worth trying if you do an AMP test on the live from battery?
I do not have one of these optimates, just a normal charger, is the indicator part of the optimate always connected to give you an idea of the battery charge?? I see a red top optima 4.2 for £139 on ebay, going to order that tonight.

Tyre Smoke

23,018 posts

291 months

Tuesday 7th July 2009
quotequote all
A red top battery is no bloody good.














If you have a charging fault or battery drain wink

FarmyardPants

4,379 posts

248 months

Tuesday 7th July 2009
quotequote all
Tyre Smoke said:
A red top battery is no bloody good.

If you have a charging fault or battery drain wink
Quite. You're just going to kill off a more expensive battery. Al, when you connect the optimate, there's a red light to show its charging and a green light comes on when fully charged. It's not designed to charge a flat battery, just keep it topped up, so if the battery is low the red light will stay on for a while as I said. If your car is garaged I highly recommend getting one. Mine's mounted on the garage wall and I just plug it into the cigarette lighter, v handy. You can leave it on for weeks and it will keep your battery tip top.

AL 123

Original Poster:

201 posts

219 months

Tuesday 7th July 2009
quotequote all
FarmyardPants said:
Tyre Smoke said:
A red top battery is no bloody good.

If you have a charging fault or battery drain wink
Quite. You're just going to kill off a more expensive battery. Al, when you connect the optimate, there's a red light to show its charging and a green light comes on when fully charged. It's not designed to charge a flat battery, just keep it topped up, so if the battery is low the red light will stay on for a while as I said. If your car is garaged I highly recommend getting one. Mine's mounted on the garage wall and I just plug it into the cigarette lighter, v handy. You can leave it on for weeks and it will keep your battery tip top.
Well it use to go 7 days or so before flattening, i've been using the charger to get it going & then just recharging when needed, so point noted about maintaining battery rather than zapping it as need be. I'll get it going, go for a good drive, see if maintaining does the trick. I'm not convinced there are leakage problems, more irregular use & not using the charger correctly.

Storer

5,024 posts

245 months

Wednesday 8th July 2009
quotequote all
FarmyardPants said:
In my case it was an amp in the boot wired to be live 24/7. Putting a relay in, triggered by the head unit, solved that problem.

If you have an optimate it can give you a good idea how well your charging circuit is working - it should take less than half an hour or so for the LED to turn green after a good drive. Mine used to take hours, new big fuse (sanded to remove oxide and cleaned up terminals etc) brought charge time down to a few minutes. Starts fine after a week, but generally put it on the optimate so don't know how long it would last. The alarm/immob uses power even when the car is unlocked - it must be powered to receive a signal from the blipper.
After a good (long) drive the battery should be fully charged by the alternator if everything is working properly. I agree that a new battery will not cure the problem if there is a voltage drain from something other than the alarm/immobiliser but the Optima battery spins the engine over soooooo much faster even after standing for a week.

It is great not having to worry if she will start when you are out and about.

plumAJP

1,149 posts

219 months

Wednesday 8th July 2009
quotequote all
since my refurb, my battery light is on constant now. it didnt get enough use for me to see if the battery was being charged so i dont know if i have a dodgy wire to the light or if the alternator has packed in.

whats the procedure for checking the voltage coming back to the battery. i have a volt meter, i just cant remember how to do it. is it just, have the car running and put the volt meter onto the battery and the voltage should be 13v or something.

FarmyardPants

4,379 posts

248 months

Wednesday 8th July 2009
quotequote all
plumAJP said:
since my refurb, my battery light is on constant now. it didnt get enough use for me to see if the battery was being charged so i dont know if i have a dodgy wire to the light or if the alternator has packed in.
Classic big fuse symptom plum, try replacing it.

plumAJP said:
whats the procedure for checking the voltage coming back to the battery. i have a volt meter, i just cant remember how to do it. is it just, have the car running and put the volt meter onto the battery and the voltage should be 13v or something.
You can measure from the upstream (passenger) side of the big fuse and ground, should be about 14.4v above idle. Can also compare with the voltage from the other side of the fuse, which I think would be about 12v (nominal battery voltage) if the fuse has gone. There should be no difference though, obviously.