The price of a Harley battery is hard to swallow, much less the Lit-ion..yikes.

BUT, my ATV uses a Gel battery because it sits on its side. $150 all day long and this Lit-ion is stronger CCA and almost the same price.

 

This is interesting as well. Again, from the FAQ:

Q. Should I use a battery tender?
A.The short answer is "only if you really need to". Most powersports enthusiasts have gotten used to hooking up a tender to their lead-acid batteries, all the time. Shorai LFX have much slower self-discharge than the best lead acid do (1/6 to 1/7, on average), they do not sulfate as capacity drops, and they are the ultimate "deep cycle" battery, which means that they can still crank your vehicle even if the remaining capacity is quite low. Therefore most riders will not need to use a tender at all. Even a charger or tender uses energy you have to pay for, and there is always the possibility that a charger or tender can fail in some way, so if not really needed the best practice is to not use one.
A fully charged LFX can sit for a year or more and still retain adequate starting capacity, without damaging the battery. As such, any vehicle which has no current flowing when the key is OFF should never need a tender. At most it should be charged every 6 to 12 months, depending on the average storage temperature (cool storage is much better for any battery). Many older vehicles and most dirtbike/atv fall into this category.
Newer vehicles may have a significant draw even when the key is OFF, to maintain clocks and computers, etc. In this case we expect that a few hours of riding per month will be all that is needed to avoid tending. If you know that you will go a number of weeks or months without riding, you can either attach a tender, or disconnect the negative cable from the battery. In any case, during storage you may use the voltage chart above and an accurate voltmeter, and consider recharging when the battery is around the 50% capacity remaining mark, or above.

 

With all the wires and mods cramped into my battery case, I would love to have a smaller lighter battery. But i wont buy one at that price.

 

Big difference in size;

The one recommended for 09 UC is; LFX27L3-BS12
Length 6.55 inch / 16.64 cm
Width 3.95 inch / 10.03 cm
Height 6.01 inch / 15.27 cm

Harley OEM 66010-97C:
Length: 6.65 inch
Width: 5.16
Height: 6.85 inch

 

Not knocking the lith ion but to say a LA battery should not be re charged untill 50% discharged is not correct. Once explained to me is when an LA battery is fully charged the H2SO4 (sulfuric acid) solution is broken down by absorbing SO3 into the lead plates. This leaves H2O (water) in battery. Any self discharge below 13.8v (I think) releases SO3 into the solution making it a stronger sulfuric acid causing sulfating of the lead plate surfaces. Prior to getting a tender I replaced seldom ridden batteries annually. After the tenders were put in use, a life of 8 to 10 years was not uncommon. Just sayin.

 

I agree, and they are also showing-up in electric cars. My HD battery is 1½ YO now and I hope to get another couple of years out of it. By that time maybe we'll see some evolution with alternative technology, especially in price reduction. Right now I would need to have a long warranty to justify the prices for these, much more than the two years that I see for one type on Ebay. Some get five years out of a Harley battery, so what's the advantage in the lithium types other than less weight?

 

I used a much-smaller, lighter Odessey battery in my old RK and I used styrofoam to pad it. The compartment is a fixed size, so I don't see much advantage in a smaller battery except for lighter weight and you might be able to remove the cables easier.

BTW, I ran a nylon strap under my HD battery, so when I need to remove it I can pull it up easily. That makes bolt-removal easier as well as removal of the battery from the compartment. It's a bitch to remove otherwise.

 

There is good reason to keep specific gravity (i.e. voltage) up to specs on a LA battery, but I'm not sure it's that important with these AGM's (e.g. HD). Does anyone know? I rotate all my batteries on a Tender, none of them off for more than a few days and always on after use, even the AGM HD battery. Even so, I only got 3½ years out of my original, somewhat lower than the norm I would think.

 

After looking back at post #12 I think the no tender needed is talking about the lithium battery and not refering to the LA. That makes more sense because lithiums won't sulfate. When I first read it I thought they were talking about tenders in general. I sure would like to get more than 3 years out of the HD battery. I used Jet Ski LA batteries in my shovel and they held up good. Not sure how much different the new HD AGM is than the Shovel head but when the time comes I will look into it. Probably won't get a battery from the dealer.

 

I will stick with regular battery. It is cheaper and a lot more practical. JMO