Battery Problem - Again?

[jasonbc]

I'm with JasonBC on that. There shouldn't really be any drain other than an alarm that you don't have. There is very little powered when the ignition is off. One of the items that is still connected is the regulator/rectifier. If all the other items draw a blank, try unplugging the regulator/rectifier and see if the drain disappears.

The only thing drawing power with the igniton off will be the clock and odometer

[AlanH]

The only thing drawing power with the igniton off will be the clock and odometer

So are you saying the Vara disconnects the reg/rect with the ignition off then? I thought the reg/rect +ve was hardwired to an unswitched +ve on pretty much everything these days but I don't have a Vara wiring diagram to back that up.

[jasonbc]

So are you saying the Vara disconnects the reg/rect with the ignition off then? I thought the reg/rect +ve was hardwired to an unswitched +ve on pretty much everything these days but I don't have a Vara wiring diagram to back that up.

It can't do anything with the ignition off. It can only regulate and rectify a current if the current is flowing with the ignition off there will (or should be) nothing to regulate.

[AlanH]

It can't do anything with the ignition off. It can only regulate and rectify a current if the current is flowing with the ignition off there will (or should be) nothing to regulate.

However, if the reg/rect is malfunctioning, one failure mode will allow a leakage current from the +ve which is attached to the battery to the earth and this will flatten the battery.

[Dave]

OK Guys here's the latest!

I disconnected all accessory terminals from the battery terminals and I still appear to have a drain on the battery.

I then disconnected both the reg/rec connectors - a squarish white one with 3 yellow wires and a flatish brown one with a red and a green wire - the drain is still present undiminished.

I then started pulling all the fuses in the main fuse box and the drain dissappeared as soon as I pulled the ODO, Clock, Indicator fuse.

So as has been said the only drain on the battery should be the ODO & clock (and this appears to be the case) but the drain which fluctuates rapidly on the digital readout between 500ma and 700ma, seems excessive.

Any ideas or do I now take a trip to my local dealer? Many thanks

Dave

[AlanH]

Well, it's not the regulator/rectifier causing the drain in that case. Fault finding is now a case of unplugging everything on that circuit until the drain disappears. If it doesn't disappear then you've got some wiring issues or an ignition switch fault maybe. A wiring diagram at this point would be very useful.

[jasonbc]

However, if the reg/rect is malfunctioning, one failure mode will allow a leakage current from the +ve which is attached to the battery to the earth and this will flatten the battery.

Rectification is the process of turning Ac to DC ( inversion is DC to AC). So to have AC in the first place the engine must be running or it cant do anything as there would be nothing to rectify. All the regulator does is smooth the DC once it's been acheived. All they are is a couple of diodes and a resistor.

[jasonbc]

OK Guys here's the latest!


I then disconnected both the reg/rec connectors - a squarish white one with 3 yellow wires and a flatish brown one with a red and a green wire - the drain is still present undiminished.

I then started pulling all the fuses in the main fuse box and the drain dissappeared as soon as I pulled the ODO, Clock, Indicator fuse.

So as has been said the only drain on the battery should be the ODO & clock (and this appears to be the case) but the drain which fluctuates rapidly on the digital readout between 500ma and 700ma, seems excessive.


Dave

Best to start looking for poor connections corosion on terminals, water damage maybe even solder in a seperate earth and use that insted of the earth for the connector just to try to reduce the leakage. Or measure the Ohm's from the present earth to the neutral on the battery and see what your getting that way.
I had very similar problems on my mates 955i tiger daft things happening to the dash board when i opened it up all the pins had gone green and rotten i took the connection blocks out the boards and hardwired the cables to the dash PCB's hoping that would cure it, it didn't. When i looked further i took all the tape off the wiring look which ran down the right hand side of the bike and supplied the dash nearly all the cables were rotten. Cut them out soldered new ones in and it never had the problem again and that bike was just over 3 years old at th etime

[AlanH]

Rectification is the process of turning Ac to DC ( inversion is DC to AC). So to have AC in the first place the engine must be running or it cant do anything as there would be nothing to rectify. All the regulator does is smooth the DC once it's been acheived. All they are is a couple of diodes and a resistor.

...and what happens when, in simplistic terms, the diode is knackered and short circuits which then connects the resistor across the battery regardless of whether the engine is running or not? Yes, the battery goes flat.

Sure, reg/rect units used to consist of a diode pack, Zener and a ballast or even electromechanical regulators - but they are rather more complex nowadays.

Don't dismiss the idea that when they fail, they can present a resistive load across the output terminals. I'm sure many auto-electrical engineers have witnessed the same thing when tracing an odd battery drain. It's commonly observed in cars and is the cause of the charging light staying on when the ignition is turned off.

[Dave]

Hi Guys

Thanks for all the suggestions - in the end I ended up with brain fade.

Gave the vara to a local independant mechanic who promptly replaced the battery and reg/rec and charged me £220 for the privilege.

He reckoned the reg/rec wasnt doing what it should and the battery, while it had good volts, fell over as soon as you put a load on it - I suppose Optimates cant show that!

Anyway the bike is back in the garage with an optimate attached making sure the new battery is fully charged.

Dave