how to test lantern while mast is on the hard

[masthugg]

Do you have a power tool around 10-16 V? Use the battery to check your lantern.

[John_Trusty]

As noted above, you do not need much current for your test, or long-term capacity, only 12-volts. Two six-volt dry cells in series will do this, and are probably cheapest. Personally, I bought a small 12-volt sealed lead-acid battery used as a backup for home burglary alarms and such. My criteria at the hardware store were (1) 12-volt and (2) cheapest - cost about US$20. It only weighs about 250 grams, so much lighter than a full boat battery. I find I use it for several testing tasks around the house and boat where I need to light LED's or instruments.

[modernviking]

Thanks a lot all of you, with your help and inputs :-) I think i will go with the mulitmeter and try that (I'm going get one anyway at some point)
Masthugg i have a Dewalt 18v, but how would it work in reality, there's like different 7-9 "holes" where one can attach a wire to

[Emouchet]

You could test using a 9v battery. Light will turn on, may be a bit dimer than on 12v. But that should be sufficient to verify it is ok.