Why Are Lithium Batteries So Expensive?

Probably the fact that demand is rapidly outstripping supply. Practically everything rechargeable these days has a lithium battery. There's no way I'm paying 2-3 times the price for a lithium battery for the bike when the weight saving on a 200+ kg road bike is negligible.

 

Changing to a lithium battery is not quite straightforward as people may think, the charging system for one, the regulator/rectifier must be compatible for a lithium battery, otherwise overcharging can and does occur, this in turn can cause burned connecting plugs, and risk a wire failure and potential fire. People do fit lithium batteries to all sorts of machines and say "oh I haven't had any problems", that may be the case but this is pure luck if no issues arise, personally I only ever fit recommended batteries, there could be nothing worse than having your pride and joy go up in smoke, usually at the most awkward time. Regarding the weight saving, you would find it almost impossible to notice and difference riding on public roads from a machine fitted with a lithium battery as opposed to an OEM one. You would get 15 years of riding with replacing 3 OEM batteries as opposed to 1 Lithium battery, and for me the way lithium is extracted exploits both the people and countries producing it. However the main issue is safety. Ride safe all from an ageing Rocker.

 

This depends on the individual lithium battery. A drop in replacement should have a built in BMS which manages the supply from the vehicles charging system to match the charge profile of the lithium cells. What you shouldn't do is charge it off the bike with an "intelligent" charger designed for SLA batteries as these have sulfation and dead battery recovery modes which will confuse and possibly damage the battery's built in BMS and possibly the battery itself. What you get there is, effectively, a SLA BMS and a lithium BMS fighting each other. An "old fashioned" car battery charger that supplies straight DC at <14.4 volts should be OK as it replicates the charging system on the vehicle.
I still think they're an expensive "answer" to a non existent problem.

 

Here is an easy to read and short article regarding Lithium batteries.
Motorcycle electrics explained: Lithium batteries (bennetts.co.uk)

 

And don't forget about cold weather performance. If you would like the ability to ride in temperatures below 32 F then stick with lead-acid.

 

As has been said above, the weight saving virtue of LiFePO4 is sphericals. I defy anyone to be able to recognise whether a machine has a LiFePO4 or an AGM battery whilst riding it.

If the OE battery was LiFePO4 then fine, the electrical infrastructure on the machine will have been designed accordingly. Otherwise I would save my pennies and go AGM, even where the OE fit was a lead/acid unit that is open to the atmosphere.

Wikipedia is worth a read on the subject of Lithium in respect of how we get hold of the stuff and the environmental consequences of so doing. There are two methodologies, mining and the electrolysis of brine, the later appearing to be the dominant choice where nearly two million litres of brine will yield just one ton of Lithium, be it a short or long ton that’s a lot of water.

If you look after an AGM battery properly it will give an acceptable working life. One of my machines has an AGM battery that replaced the OE unit in 2010 and is still going strong, so my latest machine will follow suite when the time comes.

 

the great thing about li batteries is the size of them. they are significantly smaller than the equivalent lead acid/gfm batteries

 

Useful I suppose if you are building a custom bike but limited use on most machines. Another disadvantage is that you can't just jump start a LiIon battery from another battery if it gets drained for some reason.

 

i agree especially suited specials

 

i agree especially suited to specials