Charging

Dollywobbler · Post by **Dollywobbler** » Thu Sep 10, 2009 9:07 pm

Howdy

The BX has always been a little sluggish on the starter, particularly so this morning after a late night drive yesterday.

On that drive and at 70mph, the battery light was on very, very slightly, getting brighter if I eased off. At slower speeds, there was no sign of it.

I suspected the alternator but when I checked this evening, there was 13.7v across the battery with the engine running, even with lights, heater, HRW etc on.

That sounds pretty healthy to me so is it just a warning light issue, or am I suffering belt slippage? No noise and the tension seems ok.

Brian · Post by **Brian** » Thu Sep 10, 2009 10:43 pm

Hi,
From the information, it could be a combination of factors.

But a battery charge light glowing is not a good sign.

My best guess would be a diode going leaky and slightly draining the battery, especially over night and if the battery is old.

Check the battery volts in the morning before starting.

Good battery should indicate in this weather 12.5-13volts.

Next test, disconnect the negative terminal from the battery after a long run at night, reconnect the negative lead in the morning and see if the engine turns over faster than the previous morning.

Report findings:

jonathan_dyane · Post by **jonathan_dyane** » Thu Sep 10, 2009 11:09 pm

My money would be on bad earth and/or green corrosion in the big brown connector block by the battery. And possibly a shit battery too...

mechuccio · Post by **mechuccio** » Thu Sep 10, 2009 11:23 pm

Have you tried measuring the voltage at different revolutions?
A healthy system should do just over 14V's
I have had several experiences where an alternator would charge the battery (all be it slightly) at a stationnairy rev but when revving over 2500RPM would drop to a no charging point.
The carbon contacts including a regulator cost around 10 Euro's (which is what? 7 quid? ) There's no hassle at all replacing them in your alternator and allways worth your while.

Also I've had some experience with the switch in the boot not switching the light off so that's worth checking as well

kiwi · Post by **kiwi** » Fri Sep 11, 2009 3:26 am

Had a recent problem with the alternator light.

Tests on the alternator came back as healthy and good charging circuit, except that light was on.

Opened it up and sure enough the original bearings in the alternator and signs of wear on the brushes. As the auto electrician said unless you open it up the problem may not be so obvious.

New brushes! Fixed problem.

If it is you battery just be aware that the old leaded batteries are now being replaced by much better (supposedly) calcium batteries notable for the sight glass on them. If they become discharged in any way driving any distance will not recharge them fully even your old fashion battery charger is no longer any good. You need a specialist high power charger.
Thats assuming you have a calcium battery.

Of course like has been said could just be a short in the earth strap.

Way2go · Post by **Way2go** » Fri Sep 11, 2009 3:45 am

kiwi wrote: If it is you battery just be aware that the old leaded batteries are now being replaced by much better (supposedly) calcium batteries notable for the sight glass on them. If they become discharged in any way driving any distance will not recharge them fully even your old fashion battery charger is no longer any good. You need a specialist high power charger.
Thats assuming you have a calcium battery.

There is some truth in that but basically they won't charge fully in normal use on the BX unless the charging voltage is increased to above 14.3 anyway.

The even newer hybrid battery is more resistant to deep cycling than the lead/calcium, but is still not as good in this respect as the original lead/antimony style. Most cars supplied with hybrid batteries have their voltage regulators set to 14.3 volts, although it is reported that the higher 14.8 volt setting of GM cars does no harm if the water level is checked regularly.

Dollywobbler · Post by **Dollywobbler** » Fri Sep 11, 2009 8:47 am

Did rev it up and it refused to go higher than 13.7. Any further tests will have to wait a couple of days as I'm temporarily without the car, but thanks for the tips!

Way2go · Post by **Way2go** » Fri Sep 11, 2009 5:03 pm

Dollywobbler wrote:Did rev it up and it refused to go higher than 13.7. Any further tests will have to wait a couple of days as I'm temporarily without the car, but thanks for the tips!

If you're using the standard Battery (original lead/antimony style) then that voltage is quite the norm and will not be a problem. Check charge current too if you are able, under different battery state conditions because that will tell you more about the health of the alternator and battery.

Vanny · Post by **Vanny** » Fri Sep 11, 2009 7:24 pm

these days you can get brushes for most older alternators on the ebay, thats what i do!

MULLEY · Post by **MULLEY** » Fri Sep 11, 2009 10:49 pm

I had a duff battery recently, would always require a jump start, & then everything appeared fine, no alternator light & with a multimeter with the engine on, the reading was fine. However, must have been a knackered cell, as it would lose charge very quickly, in approx 2hrs i'd need a jump start again.

I checked the earth lead, boot light etc... so the only way i was sure was after a decent run in the car, i disconnected the battery & then re-connected it the following day, & surprise surprise the car wouldnt start. So that ruled out any sort of drain, got it tested by motor factors that i'd bought it from & they confirmed it was knackered, nice replacement now is in the car, thats from a battery thats under a year old as well

good job it came with a 4yr warranty, hope the new one lasts longer, & good luck with sorting out your problem.

Dollywobbler · Post by **Dollywobbler** » Sat Sep 12, 2009 4:46 pm

Well, left the car in town last night as I had a pool car to use. Swapped back earlier, turned the key in the BX - nothing. Click, everything electrical went off but no starter.

Turned again, slow cranking but started! Oh I love intermittent issues!

Tempted to leave it just to see how we get on in France...

Vanny · Post by **Vanny** » Sat Sep 12, 2009 4:53 pm

MULLEY wrote: However, must have been a knackered cell, as it would lose charge very quickly, in approx 2hrs i'd need a jump start again.

There is a proven method for reconditioning batteries with a 'flat' cell involving little more than a mig welder. I think it should be Googlable but basically you weld across the battery terminals, cleaning up the plates and restoring performance.

kiwi · Post by **kiwi** » Sat Sep 12, 2009 10:15 pm

You stated you checked the voltage on the battery.

Did you check the voltage on the positive cable (possibly where some bare cable exposed?) It could be something simple like replacing the the terminal connections on the battery. The original lead ones can cause problems so may be worth replacing.

Thats another source of suspicious electrical problems that I put down to a lazy starter or faulty battery myself.

And cheap to sort as well.

Dollywobbler · Post by **Dollywobbler** » Sun Sep 13, 2009 11:58 am

Well, checked the voltage this morning from cold and it was 12.4v across the terminals, and exactly the same using the positive cable to gearbox earth point. However, again, there was a click and nothing first time, second time slow cranking and started. Then drove to Bury St Edmunds (towing the 2CV) and it started first time albeit slow cranking again.

Wonder if the charge light was just a peculiarity (not seen it since) and wonder whether it's just the starter motor instead? Or ignition barrel?

Dollywobbler · Post by **Dollywobbler** » Sun Sep 13, 2009 3:33 pm

Right. Some progress.

Took the earth strap off, cleaned up the contacts and that resulted in an immediate 14+v across the battery with the engine running. It seemed much more eager to crank too, though it's still a little slow.

However, rev it up and the revs drop. With lots of electrical goodies on, the voltage dropped to the low 13s and dropped to the high twelves when revved, so I think the alternator is still carked. It smelt quite nasty with a high load on it too...