Lithium Batteries. Lithium batteries have 4 cells. Each cell is 3.2 Volts, each battery is rated 12.8 Volts. Half the weight of a lead-acid battery. A good Lithium battery will contain a BMS (Battery Management System). If not, run away from it as fast as you can. This BMS is a Circuit Board mounted in the top inside of the battery housing. It babysits this battery. It does not allow the Lithium battery to be in a state of overcharged or over-discharged by shutting the battery off. Or, if you will, go to SLEEP. In SLEEP Mode the battery will read 0 Volts. You think you have a bad battery but it just needs to be woke up. Later on waking it up. A lead-acid battery's Voltage will drop as it is used. A normal occurrence. A Lithium battery will give 13.2 Volts from full charge to the point when the BMS puts the battery (still at 13.2 Volts) into Sleep mode. The BMS will not let the Lithium battery over-discharge. What this means is: The X2 Lithium will discharge down to 1% left then the BMS puts the battery into Sleep mode. The batteries made and sold in Australia will put their batteries to Sleep at 10% left when the BMS puts it into Sleep mode. Each manufacturer does their BMS to their own specifications. So, you have full Voltage to the end, unlike the lead-acid batteries.
A lead-acid battery will self-discharge in storage down 10 to 30% of full capacity while a Lithium battery will self-discharge very little over the same time frame. If you prefer leaving your battery in your Harley while in storage and the battery cables hooked up to the Harley your Harley will put an extra drain on the battery. WHY? A funny thing known as FREDs with KAMs. That is Frustratingly Ridiculous Electronic Devices with Keep Alive Memory. Those pesky little critters are an alarm, a clock, an etc., etc., etc., they do put a drain on the old Voltage box. Maybe even to include your Telematic Control Unit. However, comma, if you keep your Battery Maintainer connected to your battery that no longer is a problem to be worried about.
A Lithium battery at 12.8 Volts needs to be charged. In storage, charge this battery every 6 months or when the Voltage is less than 12.8 Volts. Use a charger designed to charge a Lithium battery. WHY? Charging Voltage is 14.6 Volts standard with a maximum of 15.0 Volts. That is why. The algorithms for the Lithium charger are 360 degrees apart and totally incompatible the lead-acid chargers. One more detail, the Voltage in a lead-acid charger does go over the 15.0 Volt range which can seriously short circuit the BMS in a Lithium battery. That is spelled ruined battery with a KER-FRIGGIN-BOOM attached to it.
Lithium - super fast charging, up to 4 times faster charging than lead-acid. 100% maintenance-free. Maximum cycle life - over 2000 cycles. Multi-position mounting. Very low self-discharge-good form seasonal use. Active intelligent monitoring BMS. Lithium Iron Phosphate (LiFePO4) cell technology delivering max instantaneous discharge current. A new battery can be used immediately if the Voltage is above 13.0 Volts. The charging Voltage should NEVER be higher than 15.0 Volts. Remove battery from Harley, or vehicle, when placing a charger directly on battery terminals. Charge the battery with a lower current than the MAX charging current. Listed tomorrow in part II. If the battery seems hot to the touch, stop charging and allow battery to cool down before resuming. After charging, leave the battery for 1 to 2 hours before checking Voltage. If the Voltage is less than 12.4 Volts, additional charging is required.
Enough for tonight @ 0133, 1 September 2022. Will finish later today.

 

A good lithium battery has electronics as well as the cells to protect against under voltage discharge, over current and over charging together with cell balancing.

All batteries with multiple cells can go out of balance and one or more cells can become "lazy" such that other cells get over charged and discharge at a faster rate. Cell balancing ensures no cell gets over charged.

The electronics is going to be a good proportion of the cost but you have to make sure the lithium battery you buy has them called a BMS.

A lot of lead acid battery chargers have a desulfate stage and that is bad for lithium. Old lead acid battery chargers do not do constant current constant voltage charging which is how a lithium batter is charged. AGM batteries are charged to 14.6 to 14.8 volts which is too high for lithium that wants 14.4 volts.

 

FWIW Dept.
The Genius 3500 tender / charger works on Lithium and "regular" battery types 6 & 12V

 

3.2 volts is the nominal voltage of a LiFePO4 cell. The full charge voltage is 3.6 volts. Hot off a charger the lithium battery voltage will be nearer 14 volts.

To prolong the life of a lithium battery it is often considered good practice to knock 1 or 2 tenths off so the charging voltage would be 14.2 or 14.3 instead of 14.4 volts. This should all be handled by a good BMS.

 

Just get a battery tender and be done with it for $30. (NOT a trickle charger or anything else but a tender). You don't ride enough to justify anything else. The tender doesn't "charge" the battery constantly, it tends it - it is a smart device that constantly monitors voltage and adjusts the amount of amperage and voltage being fed to the battery. It doesn't constantly supply power to the battery either, only when it needs it - this is what extends the life of the battery. They do have a charge mode that applies maximum amperage to the battery to charge it, if the battery voltage is low.

I have a 10 year old battery in my zero turn mower and since I only have to use that mower for 2 hours a month for 9 months out of the year, I leave it on a tender in my garage 24/7/365 for it's life. Battery still going strong.

My 2017 Street Glide battery lasted 5 years. The first 4 years I rode the bike at least weekly. The last year the bike would sit a month without being started - battery died in a year. No tender on the battery. I now leave my bike on a tender when I'm not riding it.

 

I leave my FOB in the tour pact 90% of the time. No one steals anything out here. They are not that dumb.
It have never seemed to bother the battery in the bike or the FOB. I do change the Fob battery every year.
My 2017 RGU battery was 3 years old when bike was wrecked still good.

 

People don't lock bikes out here either. Not sure it is because criminals are smarter.

I just don't want a big huge fob especially when I got multiple bikes. But I suppose not my choice.

When I heard the bike might start with fob was nearby, but not at next time, it concerned me a little. I guess I would do same as you, and leave on bike

 

A year old battery died in my Bronco when Irma came through a few years ago, stone cold dead. Worked great just before. Lightning storms have taken out plenty of my electronics, many not even on.

I have often got 5-10 years on a battery, but 3-5 years is more common.

 

Looks like I may need to replace my battery, I was hoping for next Spring. But we have at least 2 more months of riding & it faltered a little today
I don't do short rides, today was a 15 mile ride, then dropped off masonry blades at home & added another 50 miles
I was low on gas - 30 miles to empty & hazards turned on as I was going into gas stations
I figured I hit the wrong button, shut them off
As I was filling the bike they went back on
If that is a warning of a low battery that is just plain stupid, Hey yer battery is low so we will drain it some more
Plan on going with an AGM battery, that is what I put in my last bike

And if you leave your FOB on the bike, excellent reason for an Insurance Co to deny your claim