Solar and Split Charging Relay

[MartynShaw]

Hi there

We have had solar installed this week in our Boxer 2017 PVC and have nearly new gel hab batteries. Today I went to fit a Battery Master and found the LED on the split charging relay was on. The hab batteries were at about 13.7V and so was the cab battery. The engine hasn't been on today.

I went out about 2 hours after dark, put the hab light on, and the LED was still on but went off as I measured the voltages at about 12.8V on the hab and then a bit less on the cab battery.

Is this normal? If it is then the solar will keep the cab battery charged without the Battery Master? It just doesn't seem quite right, I didn't think the split charger should work the 'wrong way around'.
Thanks for any ideas.
Martyn

 

[GeoffnDee]

Has a duel output solar controller been fitted that splits the solar charging between the starter and leisure batteries ? the battery master may still be useful as it also works when mains battery charging is in use (if the mains charger only normally charges the leisure battery)

 

[MartynShaw]

Has a duel output solar controller been fitted that splits the solar charging between the starter and leisure batteries ? the battery master may still be useful as it also works when mains battery charging is in use (if the mains charger only normally charges the leisure battery)

I don't think so. It's only wired to the leisure batteries.

 

[Boldly]

Hi there

We have had solar installed this week in our Boxer 2017 PVC and have nearly new gel hab batteries. Today I went to fit a Battery Master and found the LED on the split charging relay was on. The hab batteries were at about 13.7V and so was the cab battery. The engine hasn't been on today.

I went out about 2 hours after dark, put the hab light on, and the LED was still on but went off as I measured the voltages at about 12.8V on the hab and then a bit less on the cab battery.

Is this normal? If it is then the solar will keep the cab battery charged without the Battery Master? It just doesn't seem quite right, I didn't think the split charger should work the 'wrong way around'.
Thanks for any ideas.
MartynView attachment 1035976

I fitted similar on my van and was concerned as you are. On checking their website it seems that many of these simple voltage sensing relays are two way. Mine has kept all three batteries charged for three years now.

 

[CAB96]

Yes, sometimes the split relays work both ways.