itrdave

Not seen much information on light/motorcycle batteries being used on ITR's etc. They are commonly used on track cars for weight reduction. Thought I would post my recent installation of a Scorpion lithium iron phosphate battery (model 51913), which is part of a comprehensive weight reduction program for my R. The battery is 3.5 lb (24 lb weight reduction) and cost $149 shipped from batterystuff.com. It is sized for BMW K-Series motorcycles up to 1300 cc. Scorpion is made in China by a company that makes lithium batteries for other resellers. Scorpion is a brand specific to batterystuff.com. These are a good bit less expensive than competitive products from Shorai etc. Bstuff.com has been selling these for over 2 years and claims they have as good or better performance/life as Shorai (which they also sell). Granted, 2+ years is not all that long to draw conclusions... I found one post from a guy with this exact model in an S2000 that he ran without issue for one year, then he sold the car...

This battery is rated at 550 CA (crank amps, which is not the same as CCA, or cold crank amps). It has more than plenty of amps to start the R reliably at temperatures above 40 F. As you may know, lithium batteries have one major drawback compared with lead acid, which is cold start. Amperage drops off starting at about 40 F and is very low at 0 F. These are not recommended for anybody that will be starting the engine routinely in winter below +20 F. Also, to start the engine below 35 F, you need to run the headlights for a minute before hitting starter in order to warm the battery, which actually increases its amperage (kind of the opposite of lead acid in cold conditions).

Though these batteries have plenty of cranking amperage, they do not have the same amount of energy capacity (Ah) as the stock battery - about 25% of the stock battery. This means you cannot run a bunch of accessories (stereo, alarm system, lights etc) for as long with the engine off. If your car has a lot of 'current drain' with engine off (alarm system etc), then you may have to use a float-charger if the car will be sitting for a long time without being driven. Or you can just disconnect the battery in that case...

I installed the battery 1 week ago and it is performing just like stock battery so far. Will update down the road...

pogeeboy27

iTrader: (3)

Thanks for sharing. I've been looking around for an affordable lightweight battery for a while now. I'm picking this up as soon as my Odyssey kicks the bucket.

Klasse

x2, have been interested in this, seems like a good way to drop some weight without losing much usability. OEM tie down bracket works with the smaller battery?

pogeeboy27

iTrader: (3)

Looks like you just have to cut and thread the tie down rods. Simple to do.

FutureITR

iTrader: (1)

Nice, hope it works down the road. I don't see this being an issue.
I wonder how it'll work since I have a system and a sub in the car.

itrdave

Used shorter threaded rods from Advance for $4 that fit shorter battery height perfectly with stock clamp bracket.

Only other issue is battery terminals are 'motorcycle' type which is a u-shape piece of steel with hole through it. You can get battery posts and mount them with nuts, but that is extra weight and expense. I just got a longer screw for the positive end and used a few washers as spacers. On the negative end, turned the stock cable around and mounted the clamp end to the body with a few washer 'spacers' and longer screw. The loop end that was on the body fits perfectly on the battery terminal with a screw/nut. Cheap and light, but a little more effort to disconnect negative terminal joint than a clamp.

pogeeboy27

iTrader: (3)

Could you post a couple pictures of the terminals? I need a visual.

98R#460

I installed a Ballistic 12 cell Lithium Iron battery about a year and a half back. It weighs 2.44lbs. It worked fine for daily use. Now the car sits for long periods between events. I just keep it disconnected and it keeps a charge.

Seedc2

iTrader: (1)

Battery tender okay to use on lithium batteries?

98R#460

That's what I use to top mine off occasionally, but there's no need to leave it on there if you use the car every few days or disconn the battery.
A balance charger is recommended, but I've never used one.

itrdave

Here are pics of my battery terminal connections on the Scorpion lithium. Note the ground cable is stock and just turned around with washers under the clamp end to space it off the shock tower. I put blue loctite on clamp end bolt to keep it from loosening.

Regarding charging, if the batter does not have internal cell balancing, then it is recommended to use a charger that can do that job - at least every so often in order to prevent cell imbalance from degrading the performance/life of the lithium battery. Newer batteries are now coming with internal cell balancing - the Scorpion has that feature. Battery Tender now makes a lithium specific charger that has a slightly different charging algorithm than what is used for lead batteries, but you can probably get away with a lead battery charger because the car's charging system is designed for lead batteries and seems to work just fine...

tony_2018

Damn, those are some small *** batteries. Can't wait for my yellow top optima dies.

forbiddenera

Have you considered using super caps?

itrdave

Update

Been about 1 yr since installing Scorpion Li battery. Works flawlessly - never know it was 'different', except for more sluggish starting below . Only started below 40 once (around 38).

Great product for warmer climates.

Anybody else try Li battery yet ?

pogeeboy27

iTrader: (3)

Thanks for reporting back. I have a Ballistic LiFePO4 battery in my other car but it is rarely driven and hooked up to a battery charger while sitting. No problems with it so far. I'm waiting for my Odyssey battery to die then I'll grab one of these batteries and give it a shot.

redGSRguy

I run the same one you suggested, I bought the li battery charger too but I never hook it up, so far it is working just fine.

forbiddenera

I'd love to but it can get down to -40°c (which is also -40°f) here in the winter!

itrdave

Yeah, that's crazy cold ! Lithium definitely not for anybody that sees regular snowfall in the winter...