12v battery to test mast nav lights

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dunedin

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Been a long time since I had a mast down over the winter, but it is this year so I want to test the nav light wiring before putting it back up.

When I last did this a decade ago I used a large 9v torch battery, which was good enough for old tech incandescent bulbs.
Now with all modern LED's they will likely be more voltage sensitive, so I need a 12v battery. But a long way from home (and the boat pre-launch) so need something 12v and portable. These 12v duracell are certainly portable, but will they have the grunt to test an AquaSignal Series 34 masthead light at the end of 25m of cable?
https://www.amazon.co.uk/Duracell-M...2?ie=UTF8&qid=1515949458&sr=8-2&keywords=mn21
 
This has come up before I believe. I keep an old but serviceable 7Ah burglar alarm lead acid battery for 12V testing. They are not very expensive new, but a local alarm company may have some they have exchanged with adequate life left.

Edit: but I have not got LEDS in that location, so cannot comment on the voltage per se.
 
Maybe you can borrow someone's 12v starter pack. That's what I used.

Look for someone with an old banger (car, I mean ;), they'll proobably have one. Or a battery from a golf trolley would be OK.
 
Thanks. Of course lead acid batteries (whether motorcycle batteries, old car batteries, alarm batteries etc) could work - but don’t want to lug them overseas.
Yes I could double up two 4xAA holders (advantage that have these batteries on board), or take 2 x 6v torch batteries.
Bit electrical theory wise, what reason would there be for a small 12v duracell not to work powering very briefly low wattage LEDs (I recognise I am a practical experience numpty here, but why not)?
 
An Aquasignal tricolour takes 1.5W per sector so 375mA @ 12v. Something like a 2Ah sealed alarm battery at ~£10 (or nick it out the house alarm) would do, Light is reverse polarity protected so no risk of wrong connection damage. A lithium celled battery would be lighter but whether airlines would be happy, I dinnae ken.
 
awol said:
A lithium celled battery would be lighter but whether airlines would be happy, I dinnae ken.
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There's a capacity limit in watt-hours for the size of unit (usually power-banks for portable electronics) that can be carried as personal effects without special arrangements. As long as the pack you choose is under that, I imagine it would be acceptable.

Pete
 
dunedin said:
Thanks. Of course lead acid batteries (whether motorcycle batteries, old car batteries, alarm batteries etc) could work - but don’t want to lug them overseas.
Yes I could double up two 4xAA holders (advantage that have these batteries on board), or take 2 x 6v torch batteries.
Bit electrical theory wise, what reason would there be for a small 12v duracell not to work powering very briefly low wattage LEDs (I recognise I am a practical experience numpty here, but why not)?
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These are very low power batteries. Usually specified for things like keyfobs giving out a few milliwatts in a short pulse.
They have a capacity of 50mAh. That's about the only spec they have so if you draw 400mA for a minute or two, you can't be sure the volts won't drop a fair amount.
So if the lights are dim, or don't light at all, you won't know if it's the battery or the lights.
LED navlights are not low power to electronics people, a lot of things work on microamps.

Even the AA's are a bit dodgy, they start off at 1.55V, but normally spend a lot of their working life at around 1.3V, which only just gives you about 10.4V. A lead acid battery or a mains PSU (perhaps one from a wifi router?) might be better.

There is nothing worse than testing things and not being able to trust the test equipment.
 
Different masthead light model, but my LED masthead anchor light ( I know it's not the best place ) lit happily from a 9v PP3 battery at the mast foot wires when mast down last winter. Try it....
 
jwilson said:
Different masthead light model, but my LED masthead anchor light ( I know it's not the best place ) lit happily from a 9v PP3 battery at the mast foot wires when mast down last winter. Try it....
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But if it hadn't, what would that have told you?
 
lw395 said:
But if it hadn't, what would that have told you?
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That I'd have had to run two wires from my car battery for a second test. Holding the two mast base wires to a PP3 was quicker and easier though. Masthead anchor light maybe not quite as bright as at 12v but it told me the wiring was still OK.
 
Lodesman77 said:
Why not just use a 10 slot version?

https://www.ebay.co.uk/itm/10AA-Bat...382798&hash=item1c89f7caad:g:5N4AAOSwDEtaTRqo

Works for me. Good way to carry spare charged batteries for torch/camera/etc when travelling...

.
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Because I don't happen to have a stack of them in my loft.
You are quite right, to be sure of getting over 12V, 10 cells is a good call.
10 NiCd or NimH will be a better 12V source than alkalines that drop 20% in the first half of their life.
 
I use an 18V drill battery, no problems. Many bulbs seem to be rated for 24V and engine alternators can produce up to 15V
 
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.
 
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