Shorai Battery & Sprax Alternator

Anyone know of any issues running a Sprax alternator with a Shoria lithium iron battery on a 75 MKIII. Also has a Power Arc ignition. I have it apart replacing, gues what. the sprag clutch. Lesson learned, see what the user group has to say before executing an upgrade.

I can't speak to the Sparx/Shorei compatibility, but can add something about the Shorei.

I installed a Shorai battery in my Ducati early last year and have had nothing but good results with it. It was FAR lighter than the YUASA it replaced and does a much better job starting the bike. Also, it doesn't seem to lose charge like conventional lead/acid batteries. I've left it without charging for six weeks and found that it spins the engine like it was just charged. So far a really amazing battery.

I doubt that there would be any problem using a Shorei with a Sparx system though. The Ducati has a modern charging and ignition system and works well with it. The fact that it seems to hold it's voltage well would also lead one to believe that it would work very well with any modern electronic ignition.

Saber13 said:

Anyone know of any issues running a Sprax alternator with a Shoria lithium iron battery on a 75 MKIII. Also has a Power Arc ignition. I have it apart replacing, gues what. the sprag clutch. Lesson learned, see what the user group has to say before executing an upgrade.

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Have several bikes running a SPARX 3-phase alternator with AGM batteries (not Shorai). Works great.

I have a 75' MKIII and I installed the sparx 3phase alternator the rectifier and also went with the Shorai battery and PowerArc. I replaced my sprag also but not because of the set-up it was worn. The 14amp hr battery is not big enough I feel. I replaced mine with the 18 amp hr and it is fine. Shorai had me test the 21 amp hr battery in my bike and it is the one they are going to recommend. It fits the stock battery box but is not as tall as the stock battery. It spins the motors like there is no compression in the motor! Check your engine sprocket for wear that will make the sprag slip.

Thank you gentlemen, and ladies if appropriate. Ed is prepped for upgrades, new starter wiring and ready to close as soon as the alternator get here. Will post pics soon. Thanks

dougmatson said:

I have a 75' MKIII and I installed the sparx 3phase alternator the rectifier and also went with the Shorai battery and PowerArc. I replaced my sprag also but not because of the set-up it was worn. The 14amp hr battery is not big enough I feel. I replaced mine with the 18 amp hr and it is fine. Shorai had me test the 21 amp hr battery in my bike and it is the one they are going to recommend. It fits the stock battery box but is not as tall as the stock battery. It spins the motors like there is no compression in the motor! Check your engine sprocket for wear that will make the sprag slip.

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Doug, I couldn't find the 21 amp on the Shorai website from the link you posted (in your previous thread): Can you provide a link straight to this battery? It sounds impressive.

Also is the Shorai an AGM battery and therfore needs its own special battery charger?

crusadersports said:

I couldn't find the 21 amp on the Shorai website

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http://www.shoraipower.com/c-1-batteries.aspx

LFX21A6-BS12 Sku: 4897034420692
LFX21L6-BS12 Sku: 4897034420708

crusadersports said:

Also is the Shorai an AGM battery and therfore needs its own special battery charger?

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Shorai are Lithium Iron batteries (LiFePO4) not AGM (absorbed glass mat)

http://www.shoraipower.com/t-faq.aspx

Q. Can I use Lead-Acid battery chargers or charger/tenders?A.Yes. HOWEVER, you may NOT use a charger/tender if it has an automatic "desulfation mode", which cannot be turned off. We have confirmed with Deltran, makers of the "Battery Tender" brand, that their products do NOT have a desulfation mode, and are therefore OK for use with Shorai LFX, for example. But the best possible charger/tender for Shorai LFX is the SHO-BMS01, which will be released on about March 15th 2011, we expect. It uses the 5-pin BMS port in the LFX batteries, in order to monitor, diagnose, and balance the individual cells during charge. And it also has an optimized storage mode that will give the longest possible service life to your LFX.

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My friend Wilson Pluck of American Indian Specialist just became a "dealer" of Shorai batteries and told me they are expanding the sizes & amps they make. He said you should be able to get even the 18 amp hr in the small 7 amp hr case because internaly they are very small.

I've got a 14 amp hr Shorai in my '74. So far, no issues. I do not have a Sparx alternator yet, but that will be installed in the next few weeks.

I chose this battery because of it's compact size and the fact that it can be installed laying on its side. That gave me plenty of room in the battery area to install dual Fiamm horns.

The battery was not charged for a few months when the engine was being rebuilt and worked fine after that without recharge. Overall, seems like a good choice. An added benefit is the incredibly light weight.

The 14 amp hr is fine for everything except 75's with electric staters.

dougmatson said:

The 14 amp hr is fine for everything except 75's with electric staters.

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You can easily get away with a lot less than 14AH in a kickstart Commando

Thats what I meant, 14 amp hr is overkill for a kickstart. Just don't use it for the MKIII.

dougmatson said:

Thats what I meant, 14 amp hr is overkill for a kickstart. Just don't use it for the MKIII.

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Slightly off topic but.....
a kickstart bike with a 14 ah batt and a single phase 200 stator and reg/rec unit you can run with your lights on all day and blow the horn to boot and not have to charge it for the next day.