Choosing a lithium battery

for a time osh had tractor batteries 13lbs that ran my 348 racecar just fine @60 bucks!

 

Do I understand correctly that those batteries have a very small capacity?

I guess the battery could / would go flat very quickly indeed if one had any current draw or perhaps even just left parking lights on for a couple of hours?

 

lithium technology in a battery is about getting more service from the battery... that is they are designed to perform better in daily use whuile working harder... they stand up better to many more charge / discharge cycles than typical flooded cell batteries...

weight saving is a major benefit to those that track their cars especially in competition

lithium batteries are very expensive and very good... if used in the proper enviornment... and properly maintained...

in an occasionaly used car, not properly maintained, ( to full charge ), left ignored, they can be a very expensive nightmare. Their strength comes from being used, their weakness is being under used / not maintained. The typical Ferrari owner who is not a daily driver would get better service from more conventional battery options at significantly lower cost.

 

I have a Shorai in my motorcycle and it is easily the best mod I have done to it. It weighs next to nothing and cranks the heck out of the engine.

The chemistry is such that it functions better when cold, when the engine is harder to start, so you get more consistent performance. They sell a charger for this battery to ensure the cells are each equally charged. This supposedly optimizes battery performance, though I have not tried it.

I have had this battery for a year or so and have not touched it in any way- no issues starting at all.

I want to get one of these for my car, but I think I am going to wait until Shorai gets into this market...

 

Much of the cost of lithium cells comes from the complex control systems need to assure that you don't exceed the safe charge or discharge rates.

E-cigs all use small lithium batteries.
A couple of people have had their lithium batteries light off like rockets in the charger.
A number of people have taken to using fire-proof charging bags or boxes.

http://www.amazon.com/Racers-Edge-Li-Pouch-Resistant-Charging/dp/B001HT27SQ

 

lets hope Chile will stay as our buddy - keep the lithium coming.......

 

7.5lbs is the best I can do...same battery Risi competition is using.

 

Has any one tried the Shorai LFX36A3 Lithium-Iron battery? It it is only 5lbs.... with 540 CCA!
LFX36A3-BS12

 

Their CCA ratings are "equivalent" which are a bit misleading, since they only test for a 5 second crank, instead of the industry standard of 30 seconds.

 

Lots of these high performance battery manufactures tend to bend the truth once in a while. The Oddyesy PC680 is 520 PHCA for 5 seconds. I have been doing some research and found that several Corvette owners run the Shorai LFX36A3 for track and as daily drivers as well. I am still tempted to give this battery a try for track days. But first I will measure my 348’s cracking current this weekend.

 

I am using the Sears Platinum battery, which is simply a relabled/private label Oddysey PC1500. AGM construction...4 year free replacement warranty 850 CCA. Sealed, never needs water, and cannot leak electrolyte. But it is no lightweight...49.5lbs

 

I have one of these in my Lotus, it works great, as in I notice no difference other than it weighs a whole lot less in a part of the car(left rear) where weight loss is most desired.

If you read the blurb that comes with the battery its pretty clear that you should have the Shorai charger/maintainer that goes with it. This has a special cord that plugs into the battery and so its easy to just leave the cord in the battery and plug it into the charger whenever the car sits for more than a few days. My car can sit for a week or more easily.

BTW loti are notorious for draining thier batteries within a week my shorai has been left for 3-4 days with no issues.

I got mine from battery stuff .com and they were great. Price with charger around $430.

Not sure how strong this si to start a 355 but someone here mentioned they start vettes.

I wonder if it would start my boxer, that would be a serious weight saving.

 

How long have you had the Shorai in your car?
I saw that lots of Vett ownes were using them. A few of them are using two LFX24(s) in parallel, but most are using a single LFX36.
If anyone is interested, I just measured the cranking amps for the 348tb (I have the Delco alternator). The max current requirments I measued was 191 Amps. Most of the cranks required ~155 Amps. Also, I measured a maximum 33Amps charging current @14.03 Volts on a low battery with 15+ starts. As the battery becomes charged, the alternator output current should go down.

 

Here is one interesting Corvette link that addreses the use of the Shorai battery:
Need advice on a lightweight battery - Corvette Forum

 

This is why I am surprised to see people using CCA (cold cranking amps) as a measurement of "size", since CCA is really about whether you'll get your big diesel started at zero degrees. Any CCA value over what your starter actually draws is irrelevant.

When you're trying to trade battery capacity for weight you should be looking at its Amp-hour rating, or its "reserve capacity", since these tell you how long it will last sitting in the garage with a given drain, or how long you can drive with a dead alternator, or how long you can crank it when the engine is being difficult about starting. This is the parameter that is reduced when you look for a small and light-weight battery. In the case of the LFX36 the key figure is the 36, as in it will put out 36 amps for an hour, or 18 for two hours, etc. The main thing you need to decide is how low in capacity are you willing to go which is a trade-off against how much standby drain there is when parked, and how long you want to be able to drive with a dead alternator.

Sure, if you find a small enough battery the current output can be so low that it won't spin your starter fast enough when it's fully charged, but that's a really small battery.

 

Just had it two months, the lotus has sat for about 3 days maybe 4 with no prob. The stock lead acid dies in about 7 days. Its the weird alarm on the lotus, no idea why they fit them, but it cant be removed. On the track the Lotus eats its left rear tire quickest, which makes sense as most turns are to the right and 60% of the weight is in the rear and you sit on the left. So losing 40 lbs above the left reat tire made a lot of sense to me. My freinds with a Braille, have not found them to last and they weigh double what ashorai does and are not inexpensive.

My Boxer can sit for months and the lead acid is fine, the only current draw is the little elctric clock, which is close to nothing. But opening the front clam on the boxer is always an event, so attaching a charger each week does not really seem like a great plan. If the shorai can start a vette I imagine it can do a Boxer. If there is no current draw and these batteries do not self discharge I should be Ok.

I dont run the boxer with the spare tire or tool kit in the front, this lightens it up a bit, next step is a lighter battery, but if it cant sit for weeks then the convenience of a lead acid probably wins.

Ill see how it goes on the Lotus this year and then decide. My sense is that modern cars with alarms and all types of stuff are going to kill a shorai because thye bleed any battery down. On the other hand a modern lke a vette cranks for maybe 2 secs before firing, a boxer is a little longer.

How do you connect batteries in paralell?

 

Yeak and its not unknown to loose an alternator in a boxer or at least loose the skinny little belt, fortunatly there are two alternators. You can aslo have ashort somewhere which can dran the battery in 24 hrs or less, which means youa re out $350, which sounds like alot for a bttwery, but then everything on a ferrari is so expensive 350 doesent sound too bad.

So what is the amp hr rating on anormal lead acid?

 

To get the two in parallel you order an A3 version and an L3 version of the same type of battery. The only diference between the two batteries are the teminal are flipped. You install the two batteries face to face and install a small bus bar between the two positive and an other one between the two negatives terminals. The bonus of doing it this way is that it doubles the CCA, doubles the A/Hr and doubles the batteries Max charge rate form your alternator (form 24A to 48A).
On the down side I discovered that the Shorai's CCA and reserve capacity is much less then documnted.

 

Don't completely discount CCA. Your car will require higher cranking amps as temperatures dip and oil thickens. Also, batteries lose capacity with age and wear, so starting out with additional capacity is necessary to account for that...or you may have a battery that will no longer start your car after a year or two. This is why car manufacturers put batteries with triple the CCA required for the application.

 

Typically around 70 to 90 ah.

 

The Fiamm Ecoforce VR760 shipped in the CS is 70 AH, 760 CCA. It's an AGM battery.

 

when considering reserve capacity of a battery, not all of the rated number of amperes is useable... typically less than half of the rated capacity is usable before it goes out of spec... reserve capacity is a number at a constant drain expressed in hours... a 100AH battery could be capable of delivering 25 amperes for 4 hours or 5 amperes for 20 hours, but in reality less than 50 of those amperes will be useable and in spec... batteries cannot be discharged to empty like a fuel tank, batteries are considered discharged before they reach the 50% level of charge..

an out of spec battery can damage electronics and electric motors...

 

I'm not sure removing weight from the front of a Boxer will help handling as it will increase the already rear weight bias and make it even more tail happy.