Flat battery - again

[midlife]

Another vote for ctek here. Had a Subaru that was meant to "smart charge" the battery only when needed. Usually meant don't bother charging the battery! Kept the battery in good nick with my ctek

 

[johnnyb47]

I had a car once that had a parasitic drain on the battery. I checked everything and was fast running out of ideas.
Eventually I tracked it down to the interior boot light. It decided it didn't want to turn off when I shut the boot and obviously when it's shut you can't see the lights on.
I just took the bulb out to break the circuit and all was well again (apart from a dark boot at night)

 

[swee'pea99]

Thanks again all. The comment that's really got me thinking is

Have you checked the battery terminals for corrosion and also the earth connection at the chassis?

...because tho' the answer's no, the mention of battery corrosion set me wondering whether maybe it's my DIY shims. When the new battery proved to have thinner terminals than the old one, meaning you could tighten the nuts as far as possible and the clamps would still rotate, I cut shims out of a tomato can, sanded off coatings, and used them between the clamps and the terminals. If those connections aren't as good as they ought to be, I'm thinking that may account for poor recharging? Could that be it?

Cheers.

 

[Deleted member 26715]

Thanks again all. The comment that's really got me thinking is

...because tho' the answer's no, the mention of battery corrosion set me wondering whether maybe it's my DIY shims. When the new battery proved to have thinner terminals than the old one, meaning you could tighten the nuts as far as possible and the clamps would still rotate, I cut shims out of a tomato can, sanded off coatings, and used them between the clamps and the terminals. If those connections aren't as good as they ought to be, I'm thinking that may account for poor recharging? Could that be it?

Cheers.

Sounds like you were sold the wrong battery

 

[johnnyb47]

Could well be and it wouldn't cost you anything to check your self.
When you think about it if two metals of different sorts are in contact with each other they can also cause a reaction to which they corrode (can't remember the exact name)
You would be having three different metals on your battery terminals. The battery lugs would be lead, the leads would be steel and then the tin of can. If there's a bad connection because there either loose or corroded the voltage or amperage drawn to your starter motor will be down. Modern cars with ecu,s will detect the this and will stop it dead in its tracks from turning the starter motor in order to protect the delicate electronics systems of the car.
It's always wise to check and do the cheap things first before paying out

 

[swee'pea99]

Could well be and it wouldn't cost you anything to check your self.
When you think about it if two metals of different sorts are in contact with each other they can also cause a reaction to which they corrode (can't remember the exact name)
You would be having three different metals on your battery terminals. The battery lugs would be lead, the leads would be steel and then the tin of can. If there's a bad connection because there either loose or corroded the voltage or amperage drawn to your starter motor will be down. Modern cars with ecu,s will detect the this and will stop it dead in its tracks from turning the starter motor in order to protect the delicate electronics systems of the car.
It's always wise to check and do the cheap things first before paying out

Thanks, that's really helpful. Well, it doesn't just stop it. It's kind of old-school. The starter starts sounding a bit reluctant, a few days later it turns the engine once or twice, then stops. And that's that, dead battery.

You say I could test to find out if this is the problem. Could you please say how I would go about it? Bearing in mind my skills in these sorts of areas are very limited.

Thanks.

 

[johnnyb47]

First i would give the battery a charge.
You could then either pop down to a motor factor's and buy some correct sized battery connectors that would fit the terminals snuggly and see how things go with that.
If you don't want to jump the gun by buying these only to find out its either your battery's on the way out, temporarily fit some new shims making sure they've got a nice tight fit.. If you feel it's solved your problem you could then go ahead and buy some correct sized terminals..
If all this fails you've got to start thinking about other options. Usually when an alternator fails a warning light will illuminate on the dash (especially on old school cars)
If this is not the case it could be one of two things.
The car either has a parasitic drain on the battery.
This could be caused by anything but before taking it to the garage check the easy obvious things like, is the boot light staying on when it's shut. Just simply take the bulb out tomorrow and again see what happens.
Have you got anything that's plugged into your cigarette lighter constantly. Some cigarette lighters on certain cars can be constantly wired live, even with the ignition off.
Sometimes after market radios can cause problems(if you have one)
After checking these simple things it can only really point to a more in depth issue with its electrical systems.
A decent garage would be able to check your battery. They don't just check its voltage. They can check it whilst putting it under load..
As a point of interest how often do you use your car and how many miles do you normally do on each trip
All the best
Johnny

 

[johnnyb47]

If you do use shims made out of a tin can etc make sure you clean them down to bright shiny metal before you fit them. 👍

 

[johnnyb47]

Year's ago i loved working on my car. It was easy and everything was easily accessible to get to. You could self learn about how things worked and was never afraid to having a go.
Nowadays though I hate going near the dam things.. There's no room under the bonnet to get to anything and are horrendously complicated.
Tomorrow I've got the unpleasant task to changing a headlight bulb.. Year's ago it as simple as lifting the bonnet up to getting access to the back of the light.
Tomorrow though it's a case of lying under neath the car in the muck and contorting my arthritic hand blindly into a tight space searching for the bulb connector.

 

[Deleted member 26715]

Thanks, that's really helpful. Well, it doesn't just stop it. It's kind of old-school. The starter starts sounding a bit reluctant, a few days later it turns the engine once or twice, then stops. And that's that, dead battery.

You say I could test to find out if this is the problem. Could you please say how I would go about it? Bearing in mind my skills in these sorts of areas are very limited.

Thanks.

Do you have access to a multimeter?

 

[swee'pea99]

Do you have access to a multimeter?

I do. I'm no great expert with it, but I can usually work out the settings I need. What should I be checking?

(Incidentally, I did read upon the importance of absolutely cleaning off any coatings when making the shims - I'm pretty sure I did that. I'm still concerned that they may be a bit loose, even now, so I'm still getting a slightly iffy connection. At a guess, 75% good - but that lost 25% means it can't keep up with the drain on the battery at this time of year. Make sense? If there's anything specific I can check, I'm definitely up for it. 😊)

 

[Pale Rider]

Smart charger.

Be wary of smart chargers.

To operate, they rely on reading a minimum voltage from the battery.

If the battery is dead flat, they won't recharge it.

 

[Deleted member 26715]

I do. I'm no great expert with it, but I can usually work out the settings I need. What should I be checking?

Start by checking the voltage without ignition on, then again with it on, it should hold a stable 12.8Vish, then if you have an assistant get them to watch the meter as you try to crank, if it drops to 10Vish then you have a cell gone. This time of year is battery heaven of the car spares shops, these really cold nights kill them off.

If you get it running you should see 13.5+V anywhere up to about 14.2V, then leaving it on tickover, put your headlights on full beam, you blowers on fast, your heated rear screen & mirrors, wipers, the voltage should dip very slightly as you turn them on, but should recover almost immediately, which proves your alternator is good.

But my money is on the battery, one of those things, if you can manage with just charging when not required then it will probably last the winter out & get you through the summer, but it's a risk, one I wouldn't take now, but have done through necessity in the past.

If the battery is dead flat, they won't recharge it.

Not all there are some smarter than others, but usually as you say anything less than 10V & they don't want to know.

 

[Pale Rider]

Not all there are some smarter than others, but usually as you say anything less than 10V & they don't want to know.

Smart chargers are great for their original designed use - a classic car enthusiast who keeps his vehicle in a garage and may not use it for weeks or months at a time.

Leave the smart charger connected all the time and it will do an excellent job of keeping the battery conditioned.

I suspect many users do as I did and bought a smart charger thinking it would recharge a flat battery.

For a car in general use, I would recommend a simple trickle charger, although a better recommendation is to keep the charging system in good order.

 

[swee'pea99]

Start by checking the voltage without ignition on, then again with it on, it should hold a stable 12.8Vish, then if you have an assistant get them to watch the meter as you try to crank, if it drops to 10Vish then you have a cell gone. This time of year is battery heaven of the car spares shops, these really cold nights kill them off.

If you get it running you should see 13.5+V anywhere up to about 14.2V, then leaving it on tickover, put your headlights on full beam, you blowers on fast, your heated rear screen & mirrors, wipers, the voltage should dip very slightly as you turn them on, but should recover almost immediately, which proves your alternator is good.

But my money is on the battery, one of those things, if you can manage with just charging when not required then it will probably last the winter out & get you through the summer, but it's a risk, one I wouldn't take now, but have done through necessity in the past.


Not all there are some smarter than others, but usually as you say anything less than 10V & they don't want to know.

Thanks, that's really helpful. I'll do that. Not today - crutches & snow. But as soon as I can.