Shorai Battery

[Bruce of MN]

I searched for Shorai to see if these lithium-ion batteries had been discussed before, but no results. For those who might consider them, these FAQs may be helpful: http://www.shoraipower.com/t-faq.aspx

I use a conventional 6V battery from Fleet-Farm, so I have no experience with these new-fangled things.

[Blessyouboys]

Originally Posted by Bruce of MN

I searched for Shorai to see if these lithium-ion batteries had been discussed before, but no results. For those who might consider them, these FAQs may be helpful: http://www.shoraipower.com/t-faq.aspx

Those aren't lithium ion, they are lithium iron batteries.

[Chris in WNC]

plain old group 1 6volt batteries keep getting more & more pricey, so I'm not interested in the high-dollar options ........

[Bruce Adams]

Lithium Iron Phosphate is what their chemical composition seems to state.

LiFePO4

[1930artdeco]

I used a 6v Optima and it last for 10 yrs. The last L/A battery I had lasted for 5 yrs. but then she did not get driven that much. Now she WILL get driven.

Mike

[MikeK]

Sponsored Links (Register now to hide all advertisements)

Even the largest ($315 + shipping) 6V Shorai battery, rated by them at 36AH is a loser for a street vehicle. They are rating liars. Directly from the Q&A on their website:
"Shorai batteries are rating for starting purposes. If you draw power on one like a deep cycle battery, you‘ll find about 1/3 of the capacity. Therefore, the 18AH battery would have the perceived capacity of a 6 AH battery. We recommend not discharging a battery more than 50%, so that translates to 1 hour of safe runtime for the 18 AH Shorai battery under a 3 amp load."
So you get 3 useable amp-hours from a battery they rate 18AH, 1/6 of the rating!! An A with no operating generator or alternator at night will draw about 13A with the lights and ignition. That $315 36 AH Shorai battery will give you less than an hour. The standard $65 group 1 everybody uses is rated for 150 minutes at a 25A drain rate. You would have 6 hours of useable reserve, not one before damaging the battery. For five times the price, you get one-sixth the safety reserve.

They also have very poor cold voltage performance. Below 40F (4C) they state the engine may not have enough voltage to start on the first crank. You are supposed to crank for 2 seconds to discharge-warm the battery, wait, then try again.

Shorai also states you must have a voltage regulator. A genny and cutout will make $315 toast. I like manifold cookin' but not battery.

If you're racing, have no need for real reserve capacity, and need to save weight the price is justified.

[Doug in NJ]

You wouldn't want to connect a lithium-ion battery to an A's constant-current generator!
Read this (from http://batteryuniversity.com/learn/a...on_batteries):


Lithium-ion operates safely within the designated operating voltages; however, the battery becomes unstable if inadvertently charged to a higher than specified voltage. Prolonged charging above 4.30V forms plating of metallic lithium on the anode, while the cathode material becomes an oxidizing agent, loses stability and produces carbon dioxide (CO2). The cell pressure rises, and if charging is allowed to continue the current interrupt device (CID) responsible for cell safety disconnects the current at 1,380kPa (200psi).
Should the pressure rise further, a safety membrane bursts open at 3,450kPa (500psi) and the cell might eventually vent with flame. The thermal runaway moves lower when the battery is fully charged; for Li-cobalt this threshold is between 130–150C°C (266–302°F), nickel-manganese-cobalt (NMC) is 170–180°C (338–356°F), and manganese is 250°C (482°F). Li-phosphate enjoys similar and better temperature stabilities than manganese.