External battery pack for 940 - any ideas?

[spook51]

I've read recently about external battery packs for use with various TomToms but haven't seen the answer to my question: I'd like a low-cost external power supply for my 940 when used in my positive earth classic car.

A battery pack, rechargeable from the mains, seems to be the easiest option (a couple have been mentioned in the 'Planning Walking Routes' thread) but how do I connect to the 940 using the TomTom supplied screen mount?

[Saultee]

I have a 1974 AA map of Britain which would be more in keeping with your classic!

On a serious note, I don't know about battery packs but does your classic have a cigar lighter socket? If it does the easiest solution would be to get a 2 way splitter from Halfords and swap the polarity in the plug that goes in the cigar lighter which would make it correct for your TT. As the splitter is plastic, along with your TT then short circuits are very unlikely, put a fuse in line means that any shorts would be harmless anyway.
If you don't have a ciagr lighter, you could still use the splitter put connect it to the battery or ignition controlled feed.
To check the polarity is correct for your device you could use a multimeter to check that the center pin is positive in the splitter before you connect your device.
I would put a fuse in line regardless which will ensure any shorts just blow the fuse and nothing else!

[spook51]

It's not the directions, it's the camera warnings I need - cars from the 60s can reach camera trigger speeds you know!

I'd thought about the cigar lighter and may end up doing that (thanks for the suggestion); I could convert the car to negative earth too I suppose.

[Darren]

There are any number of USB output portable battery packs that would suffice. You could then use a USb cable to power the device.

e.g. This one.
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Darren Griffin

[spook51]

Thanks Darren, that's the sort of thing I had in mind.

[Darren]

[aj2052]

A couple of suitable diodes fitted in your Cigar lighter plug would make it universal to fit into either polarity socket, no worries in any vehicle then.
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Moto G5s Plus, Sygic 17.4.8

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