Suzie Too's Gas Alarm Tips

Suzie Too - Western Caribbean
David & Suzanne Chappell
Mon 1 Aug 2011 21:43
Hiya Gang – move on ladies
Over the years I have heard many sailors complain about their boat’s gas alarm. Usually it keeps going off, for “no reason” and often drives them so mad they disconnect it.
On our new Farr 57 it is the first time we have ever had one and here is my theory to all of you that complain about a “faulty alarm”
1) You have your battery charger running or it has been running recently, charging via the engine alternator will not produce the problem
2) You have lead acid batteries, either “sealed” or wet type
What seems to happen is the as the batteries charge they give off hydrogen, which is a gas and is correctly detected by the gas alarm, as all those hydrogen molecules float by its sensor – Propane is C3H8 and Butane is C4H10, so both very high concentrations of hydrogen
So I suspect the gas alarms are set to detect hydrogen and are correctly doing their job
My solution will be to change to AGM batteries, I was surprised when we got our new Suzie Too #3 that she had lead acid batteries, but they will have to last a bit longer as we need to replace 11 of them, so a major investment, plus they are a strange size, so we will have to re-work the battery locations to get 8D types to fit, hmm.. may look at the MasterVolt slimline series
From your roving technical reporter currently in Newport, RI