Sterilising water system when in storage

I would think you will have no problem with powering the pump during the process, assuming your battery is in good shape.

 I use Puriclean, I fill the Aquaroll and add the Puriclean, then pump it into our on board tank, the water heater,  and the  pipework to all taps,  then  refill the Aquaroll and add more Puriclean.  

This then sits overnight before being pumped out and the whole system flushed with clean water.

To do that in our van our pump, which is onboard, would run for  30-40 minutes in total, and use around 30 watt hours out of the 650 watt hours safely available from our 110 amp hour battery.

Thank you for your advice.

You’ll be fine. 
I did exactly the same as @bove, albeit I left the purifying solution in the system for a few hours not overnight.

I also have an onboard tank so that means pumping the water twice. I did mine on my drive but not hooked up and battery coped no problem.

Thank you dunton 10.

Have never sterilised and still here to tell the tale. The pipe work uses drinking water (potable) spec material and the water on caravan sites comes out of a tap from the same sources as in the home. 

I also use puriclean. Don’t be tempted to use a cheaper all purpose steriliser; sure it will kill the bacteria, but won’t remove algae like puriclean will. This will affect the taste of your water. Also, regular disinfectants can contain chemicals which may be cause corrosion in your water heater. 

If you have drained water down, then to re start the system it is better to do with mains electric. I found this out thinking my battery would be suitable, but it seemed there was an airlock and couldn’t get a smooth water flow. I was advised to use mains which works better.