There is something that worries me. We have a starter battery that is in good condition. And our four domestic batteries are new. We’ve been on landline all the time, and all five batteries were fully charged when we left the marina (starter battery was 12.6V, the domestic batteries were 13.0V). They should get charged while cruising, but when we stopped at the Saracen’s Head, the voltage had dropped (starter battery was down to 12.5V, domestic batteries down to 12.4V).

The next morning the batteries were even lower. The engine didn’t start, the first time (battery was down to 11.5V), and  the domestic batteries had dropped to 10.9V.
The only appliances we used during our stop, was two internal lights (0.2 Amp/h), the water pump (0,4 Amp/h), the reading light above the bed (0.1 Amp/h) and the fridge (85 Amp/h). With the batteries fully charged (90%) we should have 396 Amp/h. We used less than 90 Amp/h, so there should be about 300 Amp/h charge left.

I wonder if our electric system is adequate to sustain us while we’re cruising. I know the fridge is the biggest power eater on the boat, so any additional lights, won’t make a significant difference. But what happens if we have to switch the inverter on to watch TV? Will inverter (2 Amp/h) + TV (10 Amp/h) + aerial booster (11 Amp/h, all for two hour use), drain the batteries? It only adds 23 Amp/h to what we take out of the batteries for lights, water pump and fridge. Should we still be OK?

But why did the batteries drop while cruising to the Saracen’s Head? And why did they fully recharge (to 13.1 (starter battery) and 13.0 (domestic batteries)) when we came back?



And why is the Battery Management System sounding an alarm, when I switch it on, telling me that the batteries are low at the moment (as you can see), while we here, in the marina, on shore power?

Is the inverter/charger on it’s way out?

On it's way out?

On it’s way out?


Life on a narrowboat, moored in a marina, is fun, but life on a narrowboat while cruising will be:

  1. even more fun
  2. f***g hard
  3. next to impossible

(Select the best possible answer. Correct answer will be revealed in a future post.)

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