Battery Tender® 12V, 800mA, Lead Acid/Lithium Selectable/ Shorai LFX18A1-12BS

I hooked this new charger up to my Mk3 Norton Shorai battery, 2 years old, LFX18A1-12BS) and obtained a full charge in 15 mins. with 14.3 volts at the end of charge.
I am using a convenient SAE plug in.
This Shorai battery has been charged off the OEM Mk3 charging system for 2 years. Never an issue.

Short term (2 days), I am happy with charger. $37 local Battery Mart

I bought a Chinese charger off Amazon that was supposed to do the same, but the battery never gets above 12.6V. Saved money and got what I paid for, not much. I'll look into this one. Thanks

I've had one for almost a year. It does the job and it's nice that one can choose between
lead acid and lithium. Not that I really need it as I've got a 3 phase alternator and LED lights,
so it seems that the lithium battery is always topped up.

"so it seems that the lithium battery is always topped up"

If it's a Shorai or other Lithium-Iron it probably isn't but in my experience it doesn't really matter from an operational point of view.

The standard Norton charging system - whether it's OEM, Podtronics, whatever - will only charge the Shorai battery to around 80-85% of it's capacity. It's easy enough to determine...check the voltage of the Shorai batt with the engine off after the bike has been sitting overnight. It will probably be in the mid/low 13's. A fully charged Shorai is 14.4vdc.

Interestingly, Shorai says that if static battery voltage drops below 12.86, only a dedicated (Shorai or equivalent) charger can "recover" the battery. In actual practice, I have seen my Shorai at voltages well below that with no issues at all and I have had the same Shorai batt in the bike since '10 or '11 (I can't remember when I first installed it but it was at least a year before I installed my Alton in '12).

The Shorai batteries have a socket to plug in their proprietary charger/maintainer. It monitors each cell separately to keep them all balanced. During storage mode I see 13.2 volts and after charge mode it'll bring it up to 14.4. That doesn't last long, under load the battery drops to 13.4 rather quickly. My system will charge to 14.2-14.5 as I ride even with the LED headlamp on except at idle.

The Shorai charger was $75 US though... this one looks like it'd do the job for less, but it's not as sophisticated.

I use a lead acid battery, but am curious what the difference is with charging a Shorai. I have a standard Battery Tender that most of the time is connected to my Sportster. The two Commandos don’t drain much while sitting.

Update on my Nov 2020 purchased Battery Tender® jr 800mA , as shown above.
- when the LiFePo4 charging cycle is selected the charger provides a 14.8 volt charge cycle
- when the Lead Acid charge cycle is selected the charger provides a 13.8 volt charge cycle

This charge rate is not mentioned in the charger specs, but simply my experience and digital volt meter readings.

This charger was not purchased based on expense. The purpose was to avoid me having to open the 3 bikes up (Norton , other British) , take out the tucked away battery to access the central Shorai charging point. This new charger will plug into a simple SAE, two prong connector.
The Norton Mk3 uses the 1975 stock Lucas system to recharge this Shorai LFX18A1-12BS, for two years, 5000 miles.
The other Brits use Alton dynamo/Podtronics to recharge same Shorai LFX18A1-12BS for 2 weeks, zero miles.