Saturday 27^th October 2012

When we are at anchor, the solar panels and wind generator do an excellent job of charging the batteries, with back-up from the generator when needed.  Over the last few weeks, though, because we’ve had days of little wind and lots of cloud (all thanks to hurricane Sandy further north), they haven’t been able to keep up and we’ve had to run the generator often.  So, as the generator produces enough power to support the battery charger twice over, we decided to fit another battery charger to charge the batteries twice as fast. 

As luck would have it, the local chandlery had just the charger we were looking for, so Steve set off on the courtesy bus to buy it and all the bits and pieces needed to fit it.  That was day 1.  On day 2 we fitted it (this is the royal ‘we’ really because Steve fitted it – but I was very handy at reading instructions (which Steve never does) and passing tools).  By the end of the day the new charger was fitted and working.  Great!  Except it wasn’t registering on the Battery Monitor.  So, a cold beer and a bit of head-scratching later, we realised we had by-passed the shunt which measures the current in and out of the batteries.  So, day 3 involved another trip to the chandlery to buy more cable and a bus bar (as there was no room for another cable at the shunt) which we then fitted.

Success!  The new charger was not only working but also registering on the battery monitor so we could see what was happening.  Basically, the monitor shows the net effect of the two battery chargers (one charges at up to 50 Amps and the new one at 60 Amps) plus any input from the solar panels and wind generator, minus any power being drawn by boat systems like the fridge, watermaker etc.  It also shows the percentage charge and voltage level of the batteries.  When we switched both battery chargers on, we were charging at over 100 Amps.

The battery monitor showing 101.2Amps going into the batteries.

We were very pleased with ourselves, and had a celebratory beer of course.  Then Steve checked the wiring and found it was getting warm.  Not good.  So we checked the instruction manual again and realised that we had probably misinterpreted the instructions on size of cabling for length of run to and from the battery.  So, day 4 involved yet another trip to the chandlery to buy thicker cable and new lugs to fit it, and the rest of the day re-running and fitting the new cable. 

The good news is that at the end of day 4 it was up and running and charging the batteries at full pelt.  Now ask us what we do with ourselves all day…