Thread: Flat battery - dual battery system?

hope it doesn't end up in 'your ability to buy faulty' thread...

i have no idea about electrics

good luck with it.

Ron,

Just before I took the motor out, I was having problems with the battery, until it went flat on me. I replaced with a new one and seemed fine... until the other day when I took the SC40 out of the range and put it into the BF Falcon RTV, so i could dual battery that for the fridge on our camping trip. Two days later the falcon had a flat battery and the aux battery was seemingly having trouble keeping up. Normally the fridge lasts at least two days.

So it may just be co-incidence but maybe mine was faulty all along too.

Stu

Mine's an SC40 as well.

I've just had battery issues over the New Year break too. It would not crank [was not early morning or cold]. On the first failure I put it down to earthing issues as I've had a problem before, so ran an extra earth to the block and took a long drive to charge up, yet still suffered a no start again the next day.
I did not have my multimeter with me to see what was going on. I left the fridge in the car when I got home but it started next morning no problem at 11.85 each battery. I'll check that again tonight.
Both batteries are as new [the auxilliary is brand new].
I have an SC40.

Ron;

at a guess I would say , it sounds like you need to take your battery terminals off P38a and "Trickle charge" your battery with a battery charger , I did this to the Disco batteries as they were going flat regularly ,you're probably not doing long enough driving to fully recharge your battery.

hmmmmm.... interesting.

Mine is all melted and sides have split, from the heat in the engine bay i guess, thats why i don't think it will be going back in. I don't have one here, but could you not put it on a variable power supply and see when the changeover occurs? This is how you were meant to test the dual battery kit from Jaycar that I built once upon a time. I was under the impression that they are a oneway flow (charging only).

Stu

Originally Posted by p38arover

I've been having problems lately with suffering a flat battery in the P38A if not driven for 2-3 days.

I tried disconnecting my dual battery system and the problem ceased.

I connected it back up, and I had a flat battery again today after not driving the Rangie since Sunday.

I now need to work out if it really is the dual battery system and, if so, why it's not disconnecting the second battery when the voltage drops. I need to contact the manufacturer for advice.

Do you have a multi-meter? If so, leave both the batteries in and disconnect one of terminals from the auxillary battery and put your mm in line to test if there's any current draw when the vehicle is not running. You may have some sort of current leak...

Nathan

Hi Ron, how much driving time are you actually doing because it sounds more like a lack of charge in the first place, which is a very common problem.

The SC40 itself, while connecting the batteries together, will only draw about 130ma and less than 20ma once the batteries are isolated, so it’s not going to flatten your batteries if they fully charged in the first place.

If on the other hand, you have not been doing much driving then the batteries will self discharge very quickly.