Battery draining problem – Superlight R

[Nick Bassett]

A new issue with my car! My battery has been on the way out for a long time now and I keep the car on a trickle charger to ‘keep it going’, but always planning to change the battery for this Spring. Last Sunday went out for a blat – all good. Got home, waited for the car to cool down and then attached trickle charger. Next day noticed the battery was failing to accept a charge – red error light illuminated on the CTEK. Assumed the battery had finally died, although a little odd as on the blat the previous day the car was fine. Ordered a new battery, fitted it Saturday morning ready for a blat yesterday (Sunday). Started the car after fitted new battery to check all was good – no problem, fired first time. Sunday morning car was completely flat – no charge whatsoever!

Fitted my CTEK to battery and left overnight – kill switch switched ON. Checked this morning and once more red error light illuminated on the CTEK. I’ve just completely disconnected the battery, reconnected the CTEK and almost immediately I get 2 charging lights illuminated on the CTEK and no red error light.

Seems like something is drawing current from a new battery to completely exhaust it overnight – would that be a correct assumption?

I don’t own a multimeter and would probably struggle to operate it!

Short of calling the RAC, any thoughts?

Edited April 22 by Nick Bassett
Spelling

[Jonathan Kay]

What model is the new battery? You need to test it under load. 

I strongly recommend getting a multimeter and we can help you with getting to know it. The most recent little one that I bought was a Draper DMM201 and that should be fine for your needs. (You're welcome to borrow it from Garsington, but at £23 that doesn't make much sense.)

Do you have the appropriate wiring diagrams? If not please send me a Private Message with your email address.

Which engine and ECU do you have?

Was the master switch set to isolate the battery? And did you set the immobiliser?

Jonathan

[Nick Bassett]

Hi JK - it is a direct replacement Banner from Tayna.

Yes, you're right, I probably should get a multimeter although how effective I'd be at using it I don't know! A friend has offered to pop around tonight and he knows how to operate one.

I'm pretty sure I don't have a wiring diagram - not for this car anyway - I'll email you.

Car is a Year 2000 Superlight R - Rover K VHPD running an Emerald K6 ECU. No immobiliser fitted - it was giving me problems, so removed in 2018 and been fine since.

Re. the isolator switch it was left OFF on Saturday night, so whatever it is that is using the battery could happy carry on - at that time I didn't know I had a problem.

The isolator is now switched ON and he battery completely disconnected.

The only 'addition' the car has is a charging point for my mobile phone - everything else is standard Caterham I think.

The only problem I've had in recent years was a Brise Axial starter motor I fitted - when starting it kept interfering with the Emerald, so I removed it and fitted the standard starter and it has been fine. Reading online, it seems others have had the same problem with the Brise, but without any firm conclusion as to what the problem was!

Thank you.

Edited April 22 by Nick Bassett

[Ainsley]

Just check the connection from the battery to the charger is all good.

Once or twice on my other car my CTEK showed a red light and all it turned out to be was a poor connection.

[Jonathan Kay]

22 minutes ago, Ainsley said:

Once or twice on my other car my CTEK showed a red light and all it turned out to be was a poor connection.

And I once had a CTEK smart conditioning charger that appeared to complete its cycle but wasn't charging the battery at all. That took me months to diagnose and left me even more cautious than before.

Jonathan

[Jonathan Kay]

38 minutes ago, Nick Bassett said:

... it is a direct replacement Banner from Tayna.

1 Check the fluid levels and top-up if needed.

2 Disconnect everything from the battery and stick it on the charger.

3 When the multimeter arrives measure the battery voltage:
• With nothing connected
• Connected to the car but nothing explicitly turned on
• Minimum during cranking
• At 3,000 rpm.

Jonathan

[MarkD]

 

Hi, I also have a similar car (Yr 2000 K-series) with a Banner battery, with regard to the 4 points above what readings should you normally expect to see?. I check fluid levels and just topped up last weekend but when measuring any readings I don't really know what I should be looking for.

[Jonathan Kay]

This is a quick DIY method for testing how the battery behaves under load and whether the car's charging system is working.

The minimum voltage while cranking (the convenient DIY load) should be greater than 10.5 V. As well as measuring the condition of the battery this may help to explain what's wrong with the car as electronic components, including the ECU, can drop out below this. (The surprising thing is that this can happen although the cranking speed seems fine.)

The voltage at 3,000 rpm is a test of the car's charging system, and should be greater than 14 V.

Jonathan

[MarkD]

That's great, thanks 

[StevehS3]

1 hour ago, Jonathan Kay said:

And I once had a CTEK smart conditioning charger that appeared to complete its cycle but wasn't charging the battery at all. That took me months to diagnose and left me even more cautious than before.

Jonathan

That is an awful fault condition. Not something I would consider ever happening. I will check mine now and again to be sure it is charging correctly.

[dave-canada-slr]

I was having issues with my battery and took it to a local shop. They tested it with a battery tester and determines it needed to be replaced. It might be worth doing that as well. 

[Jonathan Kay]

9 hours ago, dave-canada-slr said:

I was having issues with my battery and took it to a local shop. They tested it with a battery tester and determines it needed to be replaced. It might be worth doing that as well. 

Professionals have load testing kit that can measure the voltage and current at high current. 

The "minimum voltage during cranking" is a poor man's version of that, using the starter motor turning over the engine as the load. That can be done by any owner, and I don't know if the professional kit would add anything. And DIY means that you can follow it over time, and get an early warning of deterioration. I'd recommend doing that in the same way as checking oil and water (and battery fluid) levels.

Jonathan

PS: There isn't an offer of that kit in the equipment register, and i don't expect one. But we could do with some high voltage equipment to help with testing ignition systems...