The solar panel has been installed for three months now, probably the 'worst' period of the year for generating electricity (November through to January). Below is a table which slows how effective it is in keeping the batteries charged.
As a matter of routine I keep a record of the battery voltage and mostly record the figures each time I visit the boat. The table below shows the eleven visits prior to the solar panel being installed and the eleven afterwards. I've only shown the battery voltage at the start of each visit, before running the engine and only on the occasions when the boat had been moored, unattended, for at least 3 days.
At first glance there doesn't seem to be much difference, but for the eleven visits prior to the Solar Panel the batteries were lower than 12.7 volts on 8 occasions out of 11. After fitting the solar panel the batteries were higher than 12.7 volts on 9 occasions out of 11.
The average reading for the visits is also higher after fitting the panel, not by very much, but enough to show that despite there only being winter sun available the battery is kept topped up.
| Domestic Battery Voltage | |||
| Before | After | ||
| 12.82 | 12.73 | ||
| 12.64 | 12.85 | ||
| 12.62 | 12.73 | ||
| 12.67 | 12.80 | ||
| 12.71 | 13.05 | ||
| 12.57 | 12.53 | ||
| 12.67 | 12.89 | ||
| 12.74 | 12.70 | ||
| 12.76 | 12.95 | ||
| 12.20 | 12.85 | ||
| 12.44 | 12.88 | ||
| Average | 12.62 | 12.81 | |