With high-power mountain bike lights costing as much as £650 a set, it's important to look after them. After all, you don't want to be left in the dark next time you're out night riding or 24-hour racing. Here are some tips to keep your lights running at full power for longer.
The right charger
Modern high-power lights use two types of battery – NiMH or Li-Ion. They need different chargers – don’t mix them up, you’ll damage the batteries. Also, respect the manufacturer’s guidelines on pre-charging, however desperate you are to use the lamps.
The NiMH rules
These batteries don’t like being run ﬂ at, so recharge them when the lights begin to dim. You can recharge them from any state as they don’t suffer from the memory effect – the battery doesn’t forget where its maximum charge level is.
The Li-Ion rules
These batteries can be run totally ﬂat without harming their ability to perform. However, it’s good practice to avoid repeated runs to zero as this can cause long-term issues. Full discharge isn’t necessary between charges.
Predict battery life
Most NiMH and Li-Ion batteries will take about 300 full charge cycles. For regular riders, that’s about three years of use. Hardcore night riders will probably run spare batteries, extending that lifespan.
Do the maths
When not in use, NiMH batteries lose charge by 30 percent a month, Li-Ions by 10 percent. Post storage, Li-Ions can be used in any charge state; NiMHs should be fully charged and run to 50-75 percent before being charged to full again. After this, you can allow them to dim.
Store NiMH and Li-Ion batteries in a cool environment. NiMHs are ﬁne in a cool cupboard, but Li-Ions should be kept in the fridge – this slows their ageing process. Always allow Li-Ion batteries to return to room temperature prior to use.
Keep things clean
Taking care not to allow any moisture near the business end of the batteries, wipe them to keep them clean. Look out for mud or any other debris that may create a short circuit or cause the connections to become clogged.
The leads that connect your lights to their batteries are as important as the batteries themselves. Don’t pinch or kink them – this damages the inner wires. Also, a little dielectric grease on the connector ends can help keep water out.