Two-battery question

[scott_araujo]

Is this about the weight or just doing something different.  If it's weight I think you'd have a tough time beating the speedcell.

[ducatiz]

Its not just weight.  The speedcell is great for track and some road and if you stay in a warm climate.

I am thinking more along the lines of having a flexible battery system but also how to do it in a way that takes advantage of split weight.

If the batts are 6ah each and one dies, you can still start the bike on the remaining battery.

But that also allows you to put the batteries in different locations which might make weight dist better.

Speedcells are awesome but they are expensive and you still only have one battery

[suzyj]

Speedcells are awesome but they are expensive and you still only have one battery

Actually you generally don't.  The norm is to use two sets of 4 series cells connected in parallel, so it's actually two batteries.  Just two batteries in the one place.

The weight savings are considerable - eight A123 cells weigh 560g, whereas the standard Yuasa YT12B-BS lead acid battery weighs 4.1kg.  The Yuasa battery only has 180A CCA, whereas the A123 cells have 240A CCA.

The only issue I can see with the A123 cells is the potential for overcharging.  The recommended float voltage is 3.45V per cell (13.8V for the battery), which is commonly exceeded by the regulator circuit.  That said, there are plenty of examples of people using the cells successfully with the standard regulator with no problems.