NiMh and Li-ion batteries

tnowak · Post by **tnowak** » Mon Jul 14, 2008 1:20 pm

Does anyone have any practical experience of using these battery packs? Seems they are popular with mountain bike enthuisasts and offer very good capacities at very low weights (when compared with Nicad batteries).

For example, a 14V, 6AH Li-ion battery weighs 670g. My 12V, 7AH Yuasa Nicad weighs 2.6Kg.
Info here:
http://www.lumicycle.com/Product/Produc ... p=86&pdep=
TN

Dave Hall · Post by **Dave Hall** » Mon Jul 14, 2008 10:17 pm

It's not just the total energy capacity but the peak current supplied - eg for electrical starting. Can Li-ion cells deliver the very large starter currents needed, albeit briefly?

Pete · Post by **Pete** » Tue Jul 15, 2008 12:49 am

Lithium Ion batteries seem to be more susceptible to exploding if over charged, so personally I would not like to use one with an a/c generator, but if you are using one to run your radio GPS etc that should be fine

From my experience, a 5v 1000mAh lion battery is 4mm x 25mm x 50mm ( ish ) 3 NiCad AA batteries give something like 1300mAh at 4.5 so lions are something like 3-4 times as compact ( I guess that's why they tend to explode, they get a lot hotter if over charged )

A further downside with lions is that you cannot instantly replace them with Duracells if you forget to charge them up.

tnowak · Post by **tnowak** » Tue Jul 15, 2008 8:29 am

Sorry, should have mentioned my aeroplane has no starter or alternator. Battery used for radio and GPS only. One day probably Mode S as well.
TN