Thread: Flat battery

Disconnecting the thin ground wire from the controller (I think it's brown on mine) will disable it so any current used to sense voltage will be turned off.
You could install a small switch or a couple of quick connectors to it.

Hi Kiwi and if you had a fully charged battery when you parked the D4 for the 5-6 week, the SC80 would have taken 3 to 4 week to discharge the cranking battery ( when only one battery is in the D4 ) down to 12.0v.

At this point, the SC80 turns off and then draws about 15ma and would take at least another 50 days to discharge the battery down to just above 11.6V and you could still start the D4 with this battery voltage.

Now the problem with the figures above is that it does not cover the power used by your D4 for it’s own housekeeping.

So could the SC80 be responsible for flattening your battery, yes but there is, as you can see, a little more to it than a simple answer ( or excuse ).

I would suggest to anyone, whether they have a dual battery system or not, to take the negative terminals off all batteries in the vehicle if it is going to be left for that length of time.

Hope this is of some help to you Kiwi.

Thanks guys. After my first experience I had intended to disconnect prior to going away again. However as often happens in the last minute rush somethings get missed. Not again, I hope.

Originally Posted by rufusking

Disconnecting the thin ground wire from the controller (I think it's brown on mine) will disable it so any current used to sense voltage will be turned off.
You could install a small switch or a couple of quick connectors to it.

Yep, good one rufusking, by putting a switch in the brown earth wire or Green/Yellow earth wire ( depending on which isolator you have ).

When you turn the switch off, you will completely shut down my isolator and disconnect the batteries at the same time.

JUST DON'T FORGET TO TURN THE SWITCH BACK ON AGAIN, WHEN YOU WANT THE ISOLATOR TO OPERATE!

Originally Posted by drivesafe

Hi Kiwi and if you had a fully charged battery when you parked the D4 for the 5-6 week, the SC80 would have taken 3 to 4 week to discharge the cranking battery ( when only one battery is in the D4 ) down to 12.0v.

At this point, the SC80 turns off and then draws about 15ma and would take at least another 50 days to discharge the battery down to just above 11.6V and you could still start the D4 with this battery voltage.

Tim does the USI160 work the same way?

Can you put a switch in this to turn the 160 off in the same way as the 80?

Cheers

Hi Disco4pilot and with the user selectable switch in the In-Cab module, if you set the switch towards the LED, the USI-160 will shutdown ( turn both relays off ) when the common voltage of the batteries drops below 12.6v, and the USI-160 will then only be drawing about 15ma.

Your batteries self discharge at a higher rate than 15ma.

So if you are planning on leaving your D4 parked up for long periods of time, simply set the switch towards the LED.

If when you come back to your D4 and find the cranking battery has gone flat, flick the switch away from the LED and then back again and you will now be in Emergency Jump Start mode and you should be able to start your motor off the auxiliary battery.

If you are planning on leaving any vehicle parked up for a month or more, I still recommend you take the neg lead of all batteries in the vehicle, no matter what vehicle it is or whether it has or has not got a DBS fitted.

With the neg lead removed I assume you will need to use the key in the passenger door to lock and unlock. What happens to the alarm system when it runs down?

Hi rufusking and correct me here if I’m wrong but there is no backup battery in the D3 or D4 alarm, so it’s not a problem.

If you have an after market alarm fitted then you need to have a way around it.