Battery charging issue - SOLVED

[Smiffo]

At the risk of making myself look really stupid, I have to ask this question.

I bought a YUASA battery as a starter batt for the van in July.
Put it on charge when it was new, but never seemed to get to a point of full charge.

Now, it had enough in it to start the van anyway, and thereafter the alternator seemed to keep it charged as it should.

When I had starting issues again recently due to what I think is the fuel pump, the batt ran flat after a long time of cranking ( as you would expect. )

Put the battery on charge, and yet again it won't charge the battery....
Tried another charger I have - exactly the same thing happens...

So the question is this:
Is the Yuasa 3000 YBX3 battery in need of a beefier charger, or am I just missing something bloody obvious..!?

Batt is sealed unit, 12v obviously and 71ah and 651A

I want to sort this before the fuel pump turns up..!!

[lloydy]

what ampage is the charger your using?

[Smiffo]

what ampage is the charger your using?

Hi LLoydy - it's 11 amps.
Has a gauge on the side that shows percentage of charge - stays 20% even if left for 4 or 5 days..!!

[Oldiebut goodie]

If it is one of these all singing dancing so-called smart chargers the battery voltage can be under what the charger can 'see' so will not charge. Use a normal charger in this instance to begin the charging.

[ghost123uk]

Also, if you can measure the voltage on the battery before putting it on the charger, and again after an overnight charge (but left for an hour off the charger before measuring) and again a day later, not connected to anything, and post those three results here "we", can likely tell you more about what is going on.

[Smiffo]

OK.

Thanks both. Yes they are both `smart` chargers I think.
I measured charge level before putting the charger on.

It was 11.84v ( A bit low.!! )

The 11A charger didn't seem to start charging it at all, but my other one does - voltage was 12v with charger on, so I assume it is charging with that one.
I will leave it on overnight now, take some more measurements for you.

Seems odd that the voltage is still only 12v with the charger on though. Shouldn't it be more like 13v?

Thanks for your thoughts on this.

P.S the charger I am using now is only 2.5A rating on `sealed` mode. Is that enough?

[16vMatt]

From what I remember a battery on charge at full should be at should be at 13.2v but my memories a bit foggy.

[ghost123uk]

Yes that charging voltage of 12V is far too low. On a modern charger it should be a minimum of 13.8 and more like 14.2. However, it might rise as the battery starts to charge up, but a 2.5A charger is really not up to the job. It would take a long time to get an initial voltage of 11.84V on an ~80Ah battery to get it up to a full charge. A minimum of 5A charger is preferable, and 8A better still.

Perhaps leave it on the little charger overnight, then see if the bigger one will "kick in". If it does not, it is likely to be faulty (try it on a known good battery, say off a mates car, measuring the voltage, just to "double" test it's functionality).

[Smiffo]

Yes that charging voltage of 12V is far too low. On a modern charger it should be a minimum of 13.8 and more like 14.2. However, it might rise as the battery starts to charge up, but a 2.5A charger is really not up to the job. It would take a long time to get an initial voltage of 11.84V on an ~80Ah battery to get it up to a full charge. A minimum of 5A charger is preferable, and 8A better still.

Perhaps leave it on the little charger overnight, then see if the bigger one will "kick in". If it does not, it is likely to be faulty (try it on a known good battery, say off a mates car, measuring the voltage, just to "double" test it's functionality).

Will do Ghost.
Thanks for your input - will let you know how it goes - hope your new year was a good one.!?

[Smiffo]

Well, it looks like you were right Ghost...

My smaller charger eventually got the charge up a bit, and the voltage does increase as the battery charges up, despite being low at 12v initially.
I put my 11A charger on it after a while, and that still wouldn't start charging or see it, even when batt was at 12.5v...
( must be a faulty 11A charger. )

I left the smaller one on and it got the battery fully charged eventually after an extended period...!!

In summary, I wasn't leaving the smaller one on long enough, and the heavier duty one is duff.
At least now I have a nicely fully charged battery for when my new pump turns up.

Thanks for your pointers - I thought I was going nuts down here..!!

[ghost123uk]

Glad you got it sorted

What is the voltage on the battery now? (measured after the charger has been disconnected for a while)

[Smiffo]

Morning Ghost.

It measures 13.3v.
Sounds a little low still after a few hours off charge, but the leads on the meter show anywhere between 2-3ohm resistance rather than 0ohm.
I took it as leads being a little worse for wear as the explanation for that.

It showed 13.5v immediately after removing charger, so there has been ~0.2v drop in 8 or 9 hours.

[ghost123uk]

That reading is actually very good, showing the battery is in good condition (actually, that reading is higher than one would normally expect, with 12.9V after a rest being more usual)

The resistance in the leads will not affect voltage readings at all, nor will it affect (much) current readings in the lower ranges. 2 to 3 Ohms is a bit high though, a half decent set of multimeter leads normally show less than .5 of an Ohm. Maybe a new set is on the cards (cheap enough to buy).

[Smiffo]

That's good.

Thanks again for your input - and the others here too - I see the light at the end of the tunnel now..!!
( Just waiting for my fuel pump to make an appearance )