Keeping You On The Water

Flat Battery – Road side assistance from Windcraft Commissioning Team

Most Hanse Group boats come with separate engine and house battery banks. The engine battery bank is generally a single 12 volt battery and it is only used to start the engine. The house battery bank may be a single, or multiple 12 volt batteries (depending on the model of boat) wired in parallel. This results in 12 volt output but with a high amp hour, or “storage” capacity. A typical example of batteries wired in parallel and series can be seen below.

The problem with the two separate battery banks, is that in the unforeseen, but possible situation, where one of the banks “fail” is that you have the other bank ready to go, but unable to be accessed.

Rather than have to use “jumper cables” to access the power of the bank that has not failed, most yachts commissioned by Team Windcraft are fitted with an “emergency parallel switch”.

By turning this switch “on” all battery banks are “linked” together.

So, if for some reason your engine battery failed, you can turn the emergency parallel switch on and start the engine off the house battery bank. On the other hand, if you happened to have a failure on the house battery bank, you can turn on the emergency parallel switch and the house power can access the engine battery bank.


Another situation where the emergency parallel switch comes in handy is if you happen to blow the ANL fuse that protects the house power. If this happens you will have no access to the house battery bank (think along the lines of “I can no longer flush that electric toilet….. ). To rectify this you can swap out the ANL fuse (see picture below) with a spare that you have on board, assuming you have a spare on board……If not, turn the parallel switch on and you’ll be able to flush that electric loo.


Please be aware that with the emergency parallel you have the potential to flatten all your batteries!  For this reason it is called an “emergency parallel switch” and should only be used to get yourself out of trouble in these uncommon situations.

On a Hanse yacht it is normally located near the house battery bank, under the port saloon seat or with the electrics under the nav table. The emergency parallel switch should not be left in the on position for normal everyday use and only used in “emergency” situations.

Understanding the battery setup on your Hanse, Moody or Dehler can ensure correct management of your power setup adding to your enjoyment afloat.

If you are unsure of how your boat is setup, need to purchase spare fuses or wish to explore options of further battery monitoring please  seek assistance from our in house marine electrician by contacting the Windcraft service centre at [email protected]

Posted By admin on January 29, 2016 at 5:04 pm