Its freezing cold at camps at night. Once the sun sets the temperatures dive as quickly as the setting sun, and with that all battery life starts to die. Yes, you read it. All battery life. Climbing up Kilimanjaro is one thing but be warned, it is not just yourself that needs to keep going. It’s all of those pesky little devices that we have all come to reply on so much too.
And you may be one of those people thinking – well I don’t need a phone or camera, but wait. You do need torch light and even those batteries, are at risk of giving in. And if you rely on a hearing aid, well add that to the list.
So let us have a look at the science of it. A battery relies on a chemical reactions to generate power and like all chemical reactions, it is affected by temperature.
Slight deviations in temperature, can bring about changes in the capacity and service life of the battery. Increased temperature increases the chemical metabolism and battery life increases. However when temperatures drop it reduces the chemical metabolism due to increase internal resistance and you guessed it, the capacity of the battery decreases. Batteries function best at normal room temperature so a battery running at 100% capacity at 27 degrees C will lose 50% of power at 18 degrees C, at freezing point to 20% capacity and at -20C, the battery stops working all together. When it comes to Lithium-ion, reduced temperatures result in a permanent reduction of capacity. The science is a little more complicated for Lithium batteries, but the latter will give you the idea.
This goes for devices with a small HDD as well such as IPOD’s. Anything over 3500m can result in the drives crashing, as the air pressure reduces the air cushion under the spinning rigid discs.
So how do you prevent this?
Well the answer is quite simple – snuggle up with all of your batteries at night or as soon as the temperatures drop. Packing a spare pair of warm thermal and mohair socks will go a long way to creating a nice warm package for all of your batteries.
The other thing you can do (assuming you don’t want to add on the whole solar charger route) is to lay them in the sun if you happen to stop en route for a break as this will help to increase the charge. And finally, always, carry spare batteries with you, especially headlamp batteries, as you don’t want to be stuck on the way to summit and land up in the dark.