Bit of an outside chance this, as it is auto electrics rather than electronics
But could anyone suggest how to diagnose this problem?
I have a Nissan Vanette Cargo 2.3D built 1999. One of the great things about living in a climate where is almost never rains and the night minimum temperature never goes below 12C, is that vehicles don't rot away. In fact the version of an MOT here they don't even check for corrosion from what I have seen (or for other non-essential accessories like windscreen wipers or fog lights lol)
Anyway. Thursday afternoon all was fine with the van. On Friday morning I found the battery was completely absolutely totally flat, though nothing had been left switched on (lights). The battery is six months old.
The battery read 0.05V on the van and 4V once removed. I left it standing and after 30 mins it came back up to about 6V by itself. I then used a my bench power supply with constant current/constant voltage modes to gradually coax the battery back up to charge, never going over 4A charging current and mostly under 2A – it now reads 13V without the charger, after standing a while. Fully charged should read 12.9V apparently. I am not sure the battery is any good now though as the integrated green ‘charged' LED in the battery is not illuminated.
I thought I may as well try it anyway, but before fitting it, I measured the resistance from the big heavy +'ve battery cable on the van to chassis. It reads almost short circuit, around 0.3 ohms. So that probably explains what caused the battery to totally discharge.
I would have expected that sort of fault to blow a fuse somewhere, rather than draining the battery but obviously it hasn't as the short is still there according to my DMM.
I could prove that short further, and whether the battery really does have some charge in it, if I go get a 12V bulb and connect it between battery +'ve and the big battery connector cable, though that would mean me walking 45 mins round trip to the workshop and back to go get a bulb and a bit of wire.
Any suggestions?
But could anyone suggest how to diagnose this problem?
I have a Nissan Vanette Cargo 2.3D built 1999. One of the great things about living in a climate where is almost never rains and the night minimum temperature never goes below 12C, is that vehicles don't rot away. In fact the version of an MOT here they don't even check for corrosion from what I have seen (or for other non-essential accessories like windscreen wipers or fog lights lol)
Anyway. Thursday afternoon all was fine with the van. On Friday morning I found the battery was completely absolutely totally flat, though nothing had been left switched on (lights). The battery is six months old.
The battery read 0.05V on the van and 4V once removed. I left it standing and after 30 mins it came back up to about 6V by itself. I then used a my bench power supply with constant current/constant voltage modes to gradually coax the battery back up to charge, never going over 4A charging current and mostly under 2A – it now reads 13V without the charger, after standing a while. Fully charged should read 12.9V apparently. I am not sure the battery is any good now though as the integrated green ‘charged' LED in the battery is not illuminated.
I thought I may as well try it anyway, but before fitting it, I measured the resistance from the big heavy +'ve battery cable on the van to chassis. It reads almost short circuit, around 0.3 ohms. So that probably explains what caused the battery to totally discharge.
I would have expected that sort of fault to blow a fuse somewhere, rather than draining the battery but obviously it hasn't as the short is still there according to my DMM.
I could prove that short further, and whether the battery really does have some charge in it, if I go get a 12V bulb and connect it between battery +'ve and the big battery connector cable, though that would mean me walking 45 mins round trip to the workshop and back to go get a bulb and a bit of wire.
Any suggestions?
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