12v battery to test mast nav lights

Visit the battery disposal skip in your local council tip and you will find a large selection of used batteries. Alarm companies change and dump their old 12v batteries regularly so there are usually plenty of still very usable ones for the taking.
Useful for any number of small jobs in your garage too.

You can't touch let alone remove anything from our local recycling dump, which is replete with CCTV and a manned control-hut!

To the OP: what's the problem with temporarily unstrapping your boat's existing 12v battery and moving it a few yards to where the mast is stored?
 
Thanks again for all the suggestions, and the electrical specifics about the amps draw of the lights etc. Very helpful

To the OP: what's the problem with temporarily unstrapping your boat's existing 12v battery and moving it a few yards to where the mast is stored?
Removing the engine crank battery, carrying up and down ladders and moving it 300m or so could be a fallback option. But seems a lot of time and heavy lifting work compared to the light weight 9v torch battery used for previous attempt (with old style bulbs).

The 10 x AA in a holder seems like the best pragmatic option. Light and easy, and minimal waste - as carry a store of AA batteries for other needs anyway. Alarm battery also looks good, though something extra to carry which has no other use.

If lights don’t light with the 10xAA, and all wiring has been double checked, then as last resort the heavy lifting of the crank battery is the fallback (less work than a mast climb or two).
Thanks again
 
Thanks again for all the suggestions, and the electrical specifics about the amps draw of the lights etc. Very helpful


Removing the engine crank battery, carrying up and down ladders and moving it 300m or so could be a fallback option. But seems a lot of time and heavy lifting work compared to the light weight 9v torch battery used for previous attempt (with old style bulbs).

The 10 x AA in a holder seems like the best pragmatic option. Light and easy, and minimal waste - as carry a store of AA batteries for other needs anyway. Alarm battery also looks good, though something extra to carry which has no other use.

If lights don’t light with the 10xAA, and all wiring has been double checked, then as last resort the heavy lifting of the crank battery is the fallback (less work than a mast climb or two).
Thanks again

If the lights don't work with 10 AA cells, then reach for a voltmeter. Are they putting 12V on the wires? Does the voltage drop from 15 open circuit to ??? with the light connected?
Those cheapo yellow meters are worth having.
 
20180118_162749.jpg

For reference - 10 x 2500 mAh batteries, fully charged. Alkalines would give a slightly higher voltage. lights up my masthead (non-led) tricolour - just tested...
 
Last edited:
Possibly been overthinking this (due to need to buy ahead and take everything with me).
Just received the new AquaSignal S34 LED single nav light - this tests fine with a single small 9v battery.
Clearly less resistance than a triple LED tricolour on the end of 25m cable, but happy that either the 9v or the 10xAA from boat stocks will do the job.
 
Possibly been overthinking this (due to need to buy ahead and take everything with me).
Just received the new AquaSignal S34 LED single nav light - this tests fine with a single small 9v battery.
Clearly less resistance than a triple LED tricolour on the end of 25m cable, but happy that either the 9v or the 10xAA from boat stocks will do the job.

That's good to know.
I tried a generic '12V' led bulb on 9V and it was just about visible in a dark room.
Doing your research before leaving home is never a bad idea.
 
Top