Battery Charging - pulse charge

Nov 21, 2015 20 Replies

Flat battery - I'd accidentally left one of those wireless OBD things in the socket for 2 weeks is the suspected cause. Nothing from the car - not even an interior light, and had to open the door with the key.



Connected the battery to an Aldi AutoXS CPL-2054 smart charger - read



4.5V. It's now been on charge for 18 hours, and is only reading 8V. According the the manual the charger won't move from this pulse mode until the voltage gets over 10.5V.

How long should I expect to keep the charger going like this? I do have a 'dumb' charger - is it worth putting that on to move things along? Or might the battery be spent?


I think you've killed the battery.

Chucking a dumb charger on may get it back to some kind of life, but it'll probably fail in fairly short order.

How old is the battery? It should be recoverable if fairly new, but if it's more than a few years old, it could have been due to fail soon anyway.

Chris

Not sure - the car's 5 years old. I've had it 18 months. The fit date hasn't been marked, recharge date is marked as 7/2014. So from that I'd guess it's original (Unipart 45Ah).

I don't use it much - maybe shopping every fortnight and 3 or 4 200 mile runs a year. I put the battery on the charger about a month ago thinking it might need a top-up but it was fully charged.

Given that you've spent money on an expensive smart charger, leave it connected for a week.

It might well take several days before the battery starts taking a proper charge - if ever. The pulse charging has to attempt to break down the coating on the plates. A high voltage low current charge does much the same - I use my bench PS set to 50 volts. Its current limiting will stop anything silly happening.

That the Aldi charger actually switched on is good news - it means the battery wasn't 100% flat. As it needs some volts from the battery to connect.

Letting a battery discharge to that level has probably ruined it

It won't be original if it's Unipart. Which car manufacturer?

Yes, thanks. What would you do in this situation?

Thanks - might as well leave it on for a few days, don't need the car.

So built in Swindon, probably. But I very much doubt Honda would be using Unipart batteries as OEM fit.

Quick google suggests Yuasa are OEM suppliers to Honda globally, including Swindon.

The fact it's Unipart also makes any warranty that it might have had utterly meaningless.

The Aldi smart charger is about as cheap as they come - if it's the one I'm thinking of. Under 15 quid. But don't let that fool you - it's excellent.

Absolutely.

Yep, when a neighbour asked me to rescue him my ALDI charger just wouldn't operate. He got a new battery.

The way round that is to jump a good battery across the bad with the charger also connected. It should then toggle on. You may have to leave it like that for a while before it will stay on when the good battery is disconnected.

A jump start pack is ideal for this. You might even manage with a PP3. ;-)

But as I said it can be days before a truly flat battery will recover - if ever. So buying a new one is likely the answer for most who need their car.

That sounds feasible, but I a wasn't about to remove my battery to try this, and his car was out of jump lead range.

;-)

Yep, Swindon built, and a good number of 'Made in UK' parts. Enough to cause some concern ;-)

I'll replace it with a Bosch or a Yuasa if it comes to it

It does have '3 year warranty' on the side. Not sure this situation would be covered even if I had the receipt.

The replacement battery to the latest in a line of curiosities with this car, which point to it possibly being clocked. Had the rear disks done at MOT - at 44,000 miles.

It just seems to be a ridiculous car (Type R) to buy at 3 years (mileage and SH look sound to that point), rack up a high mileage in 6 months, clock and sell. I could think of far better cars to sit in and enjoy driving for long periods. But then that's people.

Follow up: left the pulse charge on for 5 days - the last 2 of those and the battery didn't budge from 8.6V. Decided to put it on the dumb charger for an hour, and this brought it up to 10.5V, then back on the smart charger for a day, which then showed fully charged and about 14V.

There is an indicator on top of the battery, which 'sort of' indicates healthy. it's supposed to be a red dot in a green circle. The green circle is there, but feint.

Decided to get a new battery on advice here - Bosch Silver from Eurocarparts. Right performance that turned out to be - it's actually easier (and free) to get things delivered. Still, 20% off with this Friday nonsense, so £46.

I'll keep the original on for a week or two and see if it holds charge. It certainly seems to crank the engine with vigour.

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