Goldie
Well-known member
Advice please folk! My domestic battery bank does not appear to be charging effectively, whilst the engine battery does. The engine battery is approx 10 years old, the domestics (2 x 110 AH) approx 18 months. The problem manifested itself in low charge in the domestic bank despite several hours of motoring in a flat calm the previous day. The french electrician spoke no english and my french is very much of the long forgotten schoolboy level. After 3 hours of deliberations, including taking away what I believe to be the split charge relay to his workshop for testing (C'est bon apparently) he put it all back together again, pronounced himself mystified, collected his money and departed. However, whatever he did - intentionally or otherwise - seemed to work. The visual tell tale was the fridge. It's an Isotherm unit that senses when extra power (higher voltage?) is available and automatically switches to "freeze mode" to store "cold" for future use. The tell tale is that a red light comes on. After our French friend left, the red light came on when we ran the engine - it hadn't just before we experienced our low batteries. We now seem to be back to the same state again in that the domestic bank is low and the engine battery fully charged (voltages without engine running and after a rest period were 12.06v and 12.92v respectively). However, with the engine running, those voltages increased to 12.96v and 13.95v respectively. That to me indicates that some charge must be getting to the domestic bank. Does it?
The charging set up is a 70A alternator through a little green Lucas box (marked with the numbers 33 RA 12v NT and 3345 1B 1288 which I believe is the split charge relay) to 2 battery banks with independent isolator switches (no change over switch). An Adverc charge controller is also incorporated, sensing of the domestic bank and the indicator light suggests normal operation. In the hope of illuminating replies, please bear in mind that the "little green box" description is indicative of my abilities as an electrician - please phrase replies accordingly! Your wisdom is much appreciated.
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The charging set up is a 70A alternator through a little green Lucas box (marked with the numbers 33 RA 12v NT and 3345 1B 1288 which I believe is the split charge relay) to 2 battery banks with independent isolator switches (no change over switch). An Adverc charge controller is also incorporated, sensing of the domestic bank and the indicator light suggests normal operation. In the hope of illuminating replies, please bear in mind that the "little green box" description is indicative of my abilities as an electrician - please phrase replies accordingly! Your wisdom is much appreciated.
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