CHARGE QUERY

Most of our old klunkers are fitted with batteries, lead acid batteries, and these are magically kept charged by sophisticated devices that I was taught about at school. But now wizards produce lithium iron batteries and their virtues are extolled by the salesmen who hope to sell them to us. They appear to be better, especially if you use an electric leg rather than a leather boot. But are they better for the leather boot brigade, besides being lighter?

Then, if you buy a lithium iron battery, you’re told you must buy a special charger. What is different about the chargers? Cynical me thinks ‘is it a way of selling more chargers?’ And if we do need a special charger off the bike, does that mean we need to adapt the charging system on our bikes if we fit one? If not, why not?

If anyone out there has the answer(s) to this early hours, sleep-disturbing matter, please share it with me. I can then go back to dreaming of long, traffic-free, breakdown- free journeys without my charging system wrecking any lithium iron battery I might fit! Graham Lampkin, member 2894

Hmm. Do you mean ‘lithium iron’ or ‘lithium ion’? The former are typically used in electric vehicles and in solar-panel systems. The latter have become very popular recently on the custom bike scene, where most folk fit them because of their physical size; a small unit can provide very high current. A 12V/100Ah lithium-ion battery can be 75% smaller and 200% lighter than an equivalent lead-acid unit. Lithium-ion batteries also tend to be more efficient and maintain their voltage throughout their discharge cycle; trad batteries get ‘tired’ as they discharge. Lithium-ion batteries can also withstand many more discharge/ recharge cycles than lead-acid units. However, it’s worth noting that they are susceptible to ‘aging’ which means they typically fail after a certain shelf-life, whether used or not. We have a couple and just charge them with the usual charger… Rowena