Ballistic Battery opinions/thoughts?

The problem I see is that they list the optimum full charge voltage as 3.6V per cell which is 14.4V for the four cell stack. The typical bike voltage regulator will charge to 14.0V, +/- maybe 0.3V ballpark.

That means the battery is going to be undercharged by typically 400 mV (about 2.8%) or as bad as about 5% at lowest charge voltage.

Here is the worry: on Lithium Ion batteries, charging to a value 1% below ideal actually undercharges the battery's energy by about 30%. That's why Sony and sanyo absolutely required we hold the charge voltage to better than 0.5% on our charge control IC's. Very slight changes in charge voltage meant very large differences in energy delivered to the battery.

Maybe Lithium Iron is more forgiving (?) maybe not, I see no data from the battery makers on this. I would like to know how the battery will perform if it is undercharged by 5% voltage due to bike voltage regulator tolerance.

bountyhunter wrote: The problem I see is that they list the optimum full charge voltage as 3.6V per cell which is 14.4V for the four cell stack. The typical bike voltage regulator will charge to 14.0V, +/- maybe 0.3V ballpark.

That means the battery is going to be undercharged by typically 400 mV (about 2.8%) or as bad as about 5% at lowest charge voltage.

Here is the worry: on Lithium Ion batteries, charging to a value 1% below ideal actually undercharges the battery's energy by about 30%. That's why Sony and sanyo absolutely required we hold the charge voltage to better than 0.5% on our charge control IC's. Very slight changes in charge voltage meant very large differences in energy delivered to the battery.

Maybe Lithium Iron is more forgiving (?) maybe not, I see no data from the battery makers on this. I would like to know how the battery will perform if it is undercharged by 5% voltage due to bike voltage regulator tolerance.

If the average voltage measured on the system is 14.3v (as is typical), ripple peaks will likely easily hit 14.4v, so the battery will likely see more than what it needs in terms of absolute/instantaneous voltage. The regulator is only regulating average voltage, so alternator ripples and ripples due to ignition duty cycle, and even turn signals, will get through. So it's really a matter of where the ripple peaks are, and the area under those peaks. Both of those values will vary greatly depending on RPM and other conditions.

If the Li-Fe battery needs a strictly DC, 14.4v value, there is no chance of getting that from a standard charging system. If it can deal with a varying duty cycle of peaks above that, then it may work.

The problem is a standard ignition is typically about 13.6 - 14.4V (room temperature set point) but voltage regulator devices for lead acid batteries have a tempco built in of about -20mV/degC to track the tempco of a lead acid battery. That means in the winter at freezing temps, the voltage set point goes up about 400 mV. At high temps it goes down.

Bottom line: if the battery needs 14.4V to fully charge it (as their spec says): how much does it get charged if you only apply 13.8V continuously? Or 13.6? I'll wager it's something like 60 - 70% at best, probably less.

BTW: the recommended charger they sell has the "balance" feature built in. Pricey but it says it doubles the life of the battery.

www.ballisticparts.com/products/Charger/chargerBalance.php


If I was putting one of these batteries in my bike, I would wire the battery terminals out and connect it to their battery charger each time I parked it so the battery would be properly charged for next use. The typical bike regulator is going to be pretty iffy. It will charge it some while you ride, my guess is way less than 100%. It still surprises me they have absolutely no data on that available.

Do you guys want to give them a try. i have an account with them. If you like we can do a group buy

Don't understand the need for them.
Have had very few battery issues in over 30 yrs.
yeah they wear out every so often, what doesn't :laugh:

Unless it's for racing, and hotter, crisper ignition,
just another fix for something not broken

My thoughts, but hell I'm a mechanical guy, what do I know :dry:

Personally i'm buying one to conceal more easily, i like the idea of keeping the electric start but its good to have the kicker there for backup! The STD battery is way too big to conceal, if i could run it & spare the expense I would. Reading all of the above form more knowledgeable members things dont look good for me though! lol. Time will tell, i didn't buy the special Shorai charger (yet) either

ezrider714 wrote: Unless it's for racing, and hotter, crisper ignition,
just another fix for something not broken

Excellent point, but it is smaller and lighter as well. Basically it would seem that each of us would need to decide for ourselves whether the pros outweigh the cons, and vice versa.

ezrider714 wrote: Don't understand the need for them.

Strictly for size and weight reduction.

bountyhunter wrote:

ezrider714 wrote: Don't understand the need for them.

Strictly for size and weight reduction.

Exactly.

There was no lead acid battery that would fit in the space I had, with the cranking amps to be useful for cranking the bike.

If I have issues with the battery, I will be sure to post it up. It won't be up and running until next season though.

I will probably end up getting the balancing charger for it as well.

I could think of 20 things to lighten up,before even considering the battery. Hell it's not big by any stretch of the imagination.
If the weight of the battery slows down your bike you have much bigger issues with it :dry:

ezrider714 wrote: I could think of 20 things to lighten up,before even considering the battery. Hell it's not big by any stretch of the imagination.
If the weight of the battery slows down your bike you have much bigger issues with it :dry:

My stock battery with fluid, which was already smaller than the stocker, weighed about 12 lbs, IIRC.

The ballistic weighs a bit over 1 lb. That's a pretty big difference in weight on a motorcycle.

Plus, for custom applications you can mount if however you need to(sideways, upside down), in a much smaller space.

Anyway, I got mine for space reasons, but I'm not going to complain about losing another ~10lbs off my bike in the process.

tachrev wrote:

ezrider714 wrote: I could think of 20 things to lighten up,before even considering the battery. Hell it's not big by any stretch of the imagination.
If the weight of the battery slows down your bike you have much bigger issues with it :dry:

My stock battery with fluid, which was already smaller than the stocker, weighed about 12 lbs, IIRC.

The ballistic weighs a bit over 1 lb. That's a pretty big difference in weight on a motorcycle.

Plus, for custom applications you can mount if however you need to(sideways, upside down), in a much smaller space.

Anyway, I got mine for space reasons, but I'm not going to complain about losing another ~10lbs off my bike in the process.

All excellent points for sure.
Now I'm going to have to weigh mine, as I would never have guessed that much.

For custom applications, I could see the reasons for it, along with an up to date charging system to handle the modern technology.
But I'm just not buying that a charging system built in the late 70's has the ability to deal with what, back then was probably just theory. :dry:

That's the fun of working on your own bike,you can make it how YOU want it.