CTEK/ battery life?

[RSstuff]

I recently bought a 1991 car that's been in dry storage for around 10 years. The seller gave me a CTEK 3600 and said the Bosch battery has been connected to it pretty much continuously and has never been discharged. So when I put the car on the road is it likely I'll need to replace the battery?

[ssray]

No way of knowing, battery's tend to fail at extremes of temperature, cold usually.
Only one way to find out....

[Sporky]

The CTEKs do condition the battery, it's not just a constant feed.

So it might be fine.

[RSstuff]

Never used a Ctek before, it seemed to cycle between the red and green light every few hours. Before staying green.

[Panamax]

Just because a c-tek can keep a battery limping along doesn't mean the battery is good. I'd want a high current drop test at a battery specialist and be ready to buy a new one.

[Haltamer]

It’s still a 10 year old battery...

As mentioned, a quick voltage drop test / test with a proper battery tester would be worthwhile, as well as just getting the ‘general vibe’ when cranking (Light flickers, crank duration etc)

If it’s for regular use, I’d be inclined to just get it a new battery and keep that one as a backup / ‘Utility’ battery (Crocodile clips connected to a fused 12v Socket can be had on Amazon, and is very useful for running tyre pumps etc. without having to stress the starter battery / start the engine / run around the car plugging into different sockets to get enough cable reach)

[RSstuff]

It's going to be a fair weather car, doing around 3k miles a year. I had a similar car with the same battery that was still going strong at 10 years old. But that battery hadn't lived on a Ctek for 10 years.

[RSstuff]

I had the ignition and lights on for 2 or 3 minutes without the engine running, and the CTEK lights changed from green to red. Not sure if that suggests the battery doesn't have much in reserve, or it's normal? after half an hour or so, the green light was back on though.

[Panamax]

Just get a new battery.

[RSstuff]

Panamax said:

Just get a new battery.

£60 down the drain, if the battery I have is serviceable.

[E-bmw]

RSstuff said:

Panamax said:

Just get a new battery.

£60 down the drain, if the battery I have is serviceable.

After 10 years + it will be some portion of fooked.

[RSstuff]

E-bmw said:

After 10 years + it will be some portion of fooked.

Why?

[Panamax]

RSstuff said:

Why?

Lead/acid batteries deteriorate over time. Otherwise you'd see battery manufacturers promoting 8 year warranty or whatever.

Typical lead/acid battery life is up to about 5 years although some will last longer. They like to be kept fully charged either by regular use of the car or on a C-tek. They tend to suffer sulphation of the lead plates and this is worse when the battery isn't fully charged. They absolutely don't like being treated like a phone battery - flattened and charged, flattened and charged etc. The only purpose of a lead/acid battery is to deliver a few seconds of high current for the starter motor while maintaining enough voltage to run the electronics. After that, you're driving on the alternator and the battery like to sit there fully charged.

[RSstuff]

Panamax said:

RSstuff said:

Why?

Lead/acid batteries deteriorate over time. Otherwise you'd see battery manufacturers promoting 8 year warranty or whatever.

Typical lead/acid battery life is up to about 5 years although some will last longer. They like to be kept fully charged either by regular use of the car or on a C-tek. They tend to suffer sulphation of the lead plates and this is worse when the battery isn't fully charged. They absolutely don't like being treated like a phone battery - flattened and charged, flattened and charged etc. The only purpose of a lead/acid battery is to deliver a few seconds of high current for the starter motor while maintaining enough voltage to run the electronics. After that, you're driving on the alternator and the battery like to sit there fully charged.

As I said, this battery has been on a CTEK for years.

Edited by RSstuff on Tuesday 5th May 21:06

[E-bmw]

RSstuff said:

Panamax said:

RSstuff said:

Why?

Lead/acid batteries deteriorate over time. Otherwise you'd see battery manufacturers promoting 8 year warranty or whatever.

Typical lead/acid battery life is up to about 5 years although some will last longer. They like to be kept fully charged either by regular use of the car or on a C-tek. They tend to suffer sulphation of the lead plates and this is worse when the battery isn't fully charged. They absolutely don't like being treated like a phone battery - flattened and charged, flattened and charged etc. The only purpose of a lead/acid battery is to deliver a few seconds of high current for the starter motor while maintaining enough voltage to run the electronics. After that, you're driving on the alternator and the battery like to sit there fully charged.

As I said, this battery has been on a CTEK for years.

And, by your own admission is at least 10 years old.

Even treated perfectly, it will have lost a significant portion of it's capacity, hence why your charger goes to red after just a couple of minutes of low level usage.

[Alickadoo]

RSstuff said:

As I said, this battery has been on a CTEK for years.

Edited by RSstuff on Tuesday 5th May 21:06

A CTEK can prolong battery life.

It cannot prolong it indefinitely.

Try it. See how you get on. What's the worst that can happen? You will be stuck with a flat battery in some inaccessible place miles from nowhere wihout food or water and you will die a horrible death.

On the other hand, you could buy a new battery - and perhaps a jump starter for backup which you keep in the car and you will chug around happily and live to a ripe old age.

[illmonkey]

RSstuff said:

I had the ignition and lights on for 2 or 3 minutes without the engine running, and the CTEK lights changed from green to red. Not sure if that suggests the battery doesn't have much in reserve, or it's normal? after half an hour or so, the green light was back on though.

I have one, it's useless. Brand new battery in my Z4 and it always flashes yellow or red. Yet the car will start after a month of no use.

From Ctek themselves "Red: means the battery charge is below 12.4 V. It's definitely time to charge the battery. Yellow: means the battery charge is between 12.4 and 12.65 V"

You're arguing over £60 (and good advice), there are 8, nay, 9 (me) telling you to replace it... It's probably the cheapest component to replace to ensure the car starts and has a healthy battery. Why ask if you're going to argue the point?

[E-bmw]

illmonkey said:

RSstuff said:

I had the ignition and lights on for 2 or 3 minutes without the engine running, and the CTEK lights changed from green to red. Not sure if that suggests the battery doesn't have much in reserve, or it's normal? after half an hour or so, the green light was back on though.

From Ctek themselves "Red: means the battery charge is below 12.4 V.

OP, you said above the ctek went to red after a few mins light use.

A fully charged healthy battery is 12.6/7v or even a bit more.

2/3 mins of lights should just remove the "surface charge" of a fully charged battery (as in drop it to the 12.6/7v) not drop it to 12.4v.

[RSstuff]

illmonkey said:

You're arguing over £60 (and good advice), there are 8, nay, 9 (me) telling you to replace it... It's probably the cheapest component to replace to ensure the car starts and has a healthy battery. Why ask if you're going to argue the point?

If that's your idea of arguing, you must be a very sensitive soul. You struggle with maths too.

[illmonkey]

RSstuff said:

illmonkey said:

You're arguing over £60 (and good advice), there are 8, nay, 9 (me) telling you to replace it... It's probably the cheapest component to replace to ensure the car starts and has a healthy battery. Why ask if you're going to argue the point?

If that's your idea of arguing, you must be a very sensitive soul. You struggle with maths too.

You're right, sorry. Keep your battery, I'm sure it'll be fine.