nathan96
Member
Hi all Can you help me diagnose this problem its a 100AH AGM from southsidebatteries.com.au. I'll post a long version and short version
SHORT
with engine running i get approx 14V across the leads in the tray that run to the aux battery.
However when i connect these leads to the flat aux battery it reads 11.9V across the terminals. Shouldn't this read 14V (i.e. alternator is charging the aux battery
LONG
ON a recent Birdsville trip a circuit breaker got acidently opened meaning the AUX battery wasn't receiving and charge from the alternator whilst driving.
This was only noticed when the fridge started throwing a low voltage fault light a few days later. It was deeply discharged at about 11.8V
I put it on the ctek when I get home and 24+ hours later I get a green light, all charged up and good to go
Fast forward to this weekend just gone, Overnight the fridge flattens the battery to 11.9V (unusual because the battery usually last 2-3night before needing a charge). So I go for an hour drive to get some charge in but the battery is still at 11.9V. Trouble shooting time
With engine running
Voltage across starting batt is approx 14V
voltage on aux side of redarc is approx 14v
voltage across aux battery is 11.9V
weird!. I thought it would also be approx 14V (maybe voltage drop?)
So disconnect aux battery and measure voltage across cables that run to aux battery, approx 14V! so no voltage drop.
connect aux battery again and were back to 11.9V. So, this is what i dont understand and need help with.
Also with the engine running and fridge connected to the aux battery it cant run. Shouldn't the fridge be powered by the engine alternator while the engine is running? (i.e. power comes to aux battery and some bypasses it and moves onto the fridge?)
SHORT
with engine running i get approx 14V across the leads in the tray that run to the aux battery.
However when i connect these leads to the flat aux battery it reads 11.9V across the terminals. Shouldn't this read 14V (i.e. alternator is charging the aux battery
LONG
ON a recent Birdsville trip a circuit breaker got acidently opened meaning the AUX battery wasn't receiving and charge from the alternator whilst driving.
This was only noticed when the fridge started throwing a low voltage fault light a few days later. It was deeply discharged at about 11.8V
I put it on the ctek when I get home and 24+ hours later I get a green light, all charged up and good to go
Fast forward to this weekend just gone, Overnight the fridge flattens the battery to 11.9V (unusual because the battery usually last 2-3night before needing a charge). So I go for an hour drive to get some charge in but the battery is still at 11.9V. Trouble shooting time
With engine running
Voltage across starting batt is approx 14V
voltage on aux side of redarc is approx 14v
voltage across aux battery is 11.9V
weird!. I thought it would also be approx 14V (maybe voltage drop?)
So disconnect aux battery and measure voltage across cables that run to aux battery, approx 14V! so no voltage drop.
connect aux battery again and were back to 11.9V. So, this is what i dont understand and need help with.
Also with the engine running and fridge connected to the aux battery it cant run. Shouldn't the fridge be powered by the engine alternator while the engine is running? (i.e. power comes to aux battery and some bypasses it and moves onto the fridge?)