I have managed to soak my DealExtreme 900 lumen battery pack and let the circuit board corrode. Having ripped it apart to discover this I have managed to bodge it back together sufficiently to drive the LED, but without the circuit board. What is the drawback? I am not brave enough to try charging it, though I guess that the charging protection circuitry is in the charger itself?
Is this a lost cause, or is it worth salvaging the cells and sealing them into a better housing?
Having broken a bar, got low-grade hypothermia, broken a brake lever and had the lights go out on successive rides, please tell me there is a silver lining!

My limited knowledge on this has lead me to believe the charge protection is built into that PCB. I would not be charging it or using it just now as you may be able to salvage the cells. Too much charge or discharge will knacker them.

I’d go to http://www.mtbbatteries.co.uk/ and drop an email to Smudge and see if he can help you out.

Thanks for the word up Rusty.
I have sent you an email Dave.

If you decide to replace rather than fix I got the new style waterproof battery from here. It arrived within a week and despite being rather bulky I no longer worry about getting it wet.

Thanks everyone. I will probably go with the new battery pack Smudge, but it crosses my mind that things might move on before I need it again in the autumn. What can we expect from next seasons lights and batteries?