My $20 Custom 4-Battery Charger for Nikon batteries

[480sparky]

Same here. I'm far from an electrician, but I'd fear capacity issues with the wires lol.
I'd gladly carry a small power strip.

As stated, the chargers only draw, according to the label, 0.2 amps each. Four of 'em would still be less than one amp, and the cord is good for 10 times that easy.

 

[Ruidoso Bill]

What's wrong in using one of these (UK version)?

Edit: Should have read your post more carefully. You wanted something small. Fair enough...

View attachment 116062

I have the cords rolled up and also use a strip. works for me.