It’s probably the quality of the cells as opposed to the quality of the battery boxes if you’re getting low capacity.

That’s odd, I guess not all battery boxes are created equal.

I use a plastic battery case and have not noticed any drain even switched off. However I do leave it disconnected from the light when I’m not using it.

I would be tempted to measure how much resistance the battery box adds however, I guess that could explain the reduces run time.

I use RC battery (iMax B6) charger as I like to charge my cells to 4.1v per cell as opposed to 4.2v which most normal chargers use. 4.1v gets the cells to around 90% full, so you get slightly reduced capacity, but the tradeoff is you get many more cycles. I charge them at 500mA per cell usually, but if I’m in a hurry I’ll use 1000mA.

You are right it’s worth paying for a good charger if you already pay for good cells. A nice feature is that it shows you how many mAh is going into the cells during charging, so you can see if a cell has reduced capacity if you keep an eye on things.

I have no experience with Torchys batteries btw, but measuring only the voltage doesn’t tell the whole story, you really need to measure the voltage with no load and also measure the voltage under load.

Good cells that read 4.1v fresh of the charger will stay over 4v under a 1A load, but a bad cell will drop below 3v under the same 1A load.

That’s odd, I guess not all battery boxes are created equal.[/quote]

They’re not.

There are (at least) two variants of the Solarstorm battery box that are outwardly the same.

It’s the USB power converter that draws current – on some boxes, the USB is powered at all times, and draws ~10mA from the batteries (i.e it will use ~50% of the capacity of a 4 cell, 2S2P, pack in ~10 days). On others, the USB is only powered when the LED battery level indicators are switched on, and draw very little current (microamps) otherwise.

The long, thin lead to the power connector also drops quite a bit of voltage when the light is drawing current – worth replacing it with a shorter, thicker, 2 core cable and ditching the USB connector (or fitting it to a separate connection).

The boxes don’t do any charge balancing or proper over discharge protection, so if the OP has been charging the cells in the box, they could be quite well out of balance by now, restricting run time.

More info here

Check whether the USB is powered all the time on yours, or only when the LEDs on the battery box are on. If the former, then
taking the batteries out is easiest. If you’re not afraid of fiddly soldering, you can disable the USB power, but then you will lose the LED indicators, too.

Replacing the cable is easier, but still needs some fiddly soldering.

^ While a washer may work, I think a disc magnet on the cell would be safer, I use them and they work well.

Ahh, thanks for clearing that up about the battery boxes.

I have no experience of the boxes with a USB power socket as my box only has the round threaded connector which goes straight to the lights. I remember getting it from fasttech I think, it was years ago when I bought it so I don’t know the exact model.