Battery damage

[Brian Kirby]

rajco - 2016-03-01 7:45 PM

 

A bit beyond my knowledge Brian. I've checked the hab batt which was 13.5 but not clear to me what to measure next................................

Assuming you can follow the main 12V "+" cable from the battery, starting at the battery "+" terminal, try connecting your multimeter between any accessible exposed "+" terminal and an earth point (basically, any uninsulated area of the van's metal bodywork, or the head of a screw that is attaching something to the van's metal bodywork).

 

I'd start with the battery "+" terminal (i.e. between that terminal and an earth point, in lieu of connecting the multimeter to the battery - terminal). You'll then know if your problem is with the battery "-" connection, rather than the "+" connection. This is because if the "-" is not connected, no circuit can complete, so nothing will work. It is unlikely, but it just may be that simple. :-)

 

Then, just keep working your way along the cable away from the battery, from connection to connection. You should see roughly the same voltage at each point as you see when connecting the multimeter between the battery "+" and "-" terminal posts.

 

When you get to the point at which you see no volts (which, as none of the hab electrics are working you eventually should), you will have isolated the cause as lying between that point and the immediately preceding point at which you had volts. All you have to do then, is work out why! :-)

 

It may be that something inside the Nordelectronica unit has failed, or even that it includes yet another fuse for internal protection, and that has blown.

 

Disconnect any mains connection to the van before you start. :-)

 

Then, be very careful not to accidentally short anything "+" directly to earth as you continue testing.

 

12V is easy to underestimate. It is low Voltage, so you won't get any shocks, but these batteries release huge Amperages if short circuited. They'll take great chunks out of anything metallic that connects "+" to "-" by any route if there is zero resistance, and develop a deal of heat in the process. For instance, as a precaution, if your watch has a metal bracelet, take it off before you start, and just check what you are about to connect to what, as you go. The multimeter itself will be fine, but make sure its uninsulated probes/connectors stay clear of anything other than the terminal you want to test on the one hand, and the relevant earth point on the other. Good luck.

[rajco]

Weather is foul so haven't made a trip out but have made contact with FV electrician who suspects battery age as a feature. I was horrified when checking to find that both are now 6 years old.

 

Managed a quick trip to our garage (between rain storms and gales) Didn't stay long as not good light and very cold.

 

However a tip from FV to hold Test button down for ten seconds was worth a try but didn't show much. Then started the engine and tried test switch again which then worked!!!

 

It seemed that the hab area was coming back to life as the lights we tried all worked. But went out when the engine was switched off. At last some progress.

 

The FV electrician was most helpful suggesting a couple of new batteries would be a good investment to start with. We're due a service and leak test so will probably combine this with getting them to sort out the electrics and the Controle Technique. Looks like being an expensive month.

 

I'm trying to attach a copy of the FV elec layout.

 

Also the FV wording about the circuit breaker switch, translated into English.

"The circuit breaker is located below and to the right of the front passenger seat. It is designed to preserve the B2 battery when the B1 starter battery is discharged. It avoids the B2 battery being used to start the engine which risks damaging it."

 

 

[rajco]

Weather is foul so haven't made a trip out but have made contact with FV electrician who suspects battery age as a feature. I was horrified when checking to find that both are now 6 years old.

 

Managed a quick trip to our garage (between rain storms and gales) Didn't stay long as not good light and very cold.

 

However a tip from FV to hold Test button down for ten seconds was worth a try but didn't show much. Then started the engine and tried test switch again which then worked!!!

 

It seemed that the hab area was coming back to life as the lights we tried all worked. But went out when the engine was switched off. At last some progress.

 

The FV electrician was most helpful suggesting a couple of new batteries would be a good investment to start with. We're due a service and leak test so will probably combine this with getting them to sort out the electrics and the Controle Technique. Looks like being an expensive month.

 

 

Also the FV wording about the circuit breaker switch, translated into English.

"The circuit breaker is located below and to the right of the front passenger seat. It is designed to preserve the B2 battery when the B1 starter battery is discharged. It avoids the B2 battery being used to start the engine which risks damaging it."

 

 

[aandncaravan]

That was why I asked if the lights came back on when you started the engine.

That they do, does suggest a dead battery or a dead fuse right at the battery and that every thing else is ok.

Did you check the two large strip fuses that can be seen right on top of the battery in the photo. If one of those has gone, things would still work when on mains or Alternator but not when those charging systems are inactive.

 

However, DON'T connect mains if there is the slightest suspicion of the batteries as the charger will most likely pop. They are not designed to bring up a battery from dead, especially if the battery is close to End Of Life, thereby placing a double strain on the charger.

Your Nordelettronica NE143 is a Power Supply that charges batteries, not a pure Charger that is able to shut down when things get tough. for example, like a Car charger can.

 

At 6 years old I would suggest the batteries are a good place to start regardless of the real issue, but I think you have a break in the wiring close to the battery, like the strip fuses in the photo?

 

The battery + goes through those fuses then straight to the back of the Nordelettronica fuseboard, so if the Habitation lights work when on 'Starter' battery (when the Alternator is spinning and supplying 12v to the Fuseboard in lieu of the hab battery ) the break has got to be in that short bit of cable.

 

 

.

 

 

 

[Derek Uzzell]

aandncaravan - 2016-03-03 7:59 PM

 

...Did you check the two large strip fuses that can be seen right on top of the battery in the photo. If one of those has gone, things would still work when on mains or Alternator but not when those charging systems are inactive...

 

The photo I provided does not relate to Rick’s vehicle but to a later Font Vendôme “Brantome” motorhome with a pair of habitation batteries - hence (presumably) the two ‘strip fuses’. But it’s probable that Rick’s earlier “Venise" has a simlar set-up with a single strip-fuse for its sole habitation battery.