LiFePo4 Battery

Hi Fritz,

Unless you have the proper charging circuitry designed for Lithiumbatteries I wouldn't use it (assuming it isn't built in). Lithium batteries are/can be very unstable if not charged correctly and have a reputation for catching fire if misused. One common misuse is to discharge them too much which ruins them (not below 3V/cell from memory).

You can get sealed lead acid batteries designed for motorcycle use (higher discharge/charge rates) but again, these must be kept charged or they fail.

Jim

I was thinking of putting one in a total loss race bike (no alternator). Found that a LiFoPo4 battery gives less weight on bikes with starter motor as they can give good cranking amperage. But not more Ah per kilo compared to an ordinary lead battery. Maybe I have misunderstood data sheets for lithium batteries, but until proved wrong I'll stick to the old cheap lead batteries.

Mike

The one iin the pic is 36 watt hours = 3 amp hours at its12 volts. So it isn't all that big. And as Jim says... They need special chargers don't they? I'd be very nervous about fire...does the maker provide data?

Just my own experience - I cannot comment on the specific brand that you have but I have Shorai Li-Ion batteries in two of my machines. One is in a modern Sym Maxsym 400i 'superscooter' and the other is in my 2007 Enfield Electra X. I don't think that the Enfield charging system will be very sophisticated (nothing else on it is!) but the battery has been fine for the five years it's been fitted. The battery in the Sym was fitted about three years ago and has also been fine. In both cases the cranking capacity is excellent but, I suggest that if your machine has no electric starter, the only real advantage of these batteries is weight saving. I have one 'special' Shorai charger and each machine has a short 'fly-lead' that can be quickly and easily connected for mainteneance charging. The charger was circa £45.00

These batteries need to be charged with a voltage between 14 V and 15 V.

Any less than 14 volts and it will not charge. Any more than 15 V and you will irreversibly damage the battery.

Please check what voltage your system charges at.

As regards the danger of fire. If a Lithium-ion battery every catches fire then just walk away as it is near impossible to put it out even with a fire extinguisher. This is why it is now illegal to transport Lithium-ion batteries by air freight.

However, LiFePO4 (Lithium Iron Ferrous Phosphate) batteries are much less likely to catch fire, in fact nearly impossible.

So, use LiFePO4 batteries but check your charging system first.

Tony