Posted: Fri Jun 01, 2012 4:28pm

I currently have a Stirling 1800 watt inverter off 4 x 135 amp lead acid leisure batteries, which is sufficient power for most things, however, it will not run our compact washing machine. The machine only requires 600 watts for the heating element but I presume the inverter gives an unacceptable type of wave because the washing machine doesn't even begin to do a wash. My question is - should I be considering a new (different) inverter or go with a 240 volt generator that fits on the engine like an alternator? (Isuzu 42hp 4 cyl diesel with twin alternators). I realise that using the latter method I will only be able to run the washine machine whilst the engine is running and don't really know which way to go. Maybe some of you have already made this decision and I would welcome your comments on the subject, Many thanks, Keith.

Posted: Fri Jun 01, 2012 5:09pm

I see that you do not tell us which type of wave form the inverter produces but you could well be correct. However it could also be that the starting surge demanded by the motor is too great for your inverter or the cables between battery and inverter are too thin. If its the inverter that cuts out it is likley to be a surge or cables and if it stays running it is probably the wave form. I also notice that you do not give us the specifications for your alternator. The 600 watt heating element will require about 60 amps @ 12V plus whatever the washing machine motor and electronics requires. If your second alternator is rated at more than 80 amps or so then a pure sine wave inverter of 1.5 to 2kW with a high surge capacity should be the cheapest way to meet your needs. Unless you want to shorten your battery life (I see that you have not given us the results of your power audit & charging calculations)you will still only be wise to use the washing machine whilst running the engine at sufficient speed to provide a charge to cover the inverter load. This is the way most people seem to run washing machines on cruising boats unless they specify a Travel Power from new. Tony Brooks