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So I've been looking around to see what the latest and greatest in lithium battery technology is. I'm not too far from the 3,000 pound mark in my 08 C6 1LT, and I figured shaving 30# off of the Front end would just get me that much closer. I've looked at multiple options including Shorai, Odyssey, Braille, etc But I came across this that peaked my interest. Particularly because it has a built in safety for excessive discharge. This is ideal for me, as I typically drive the car every day, but don't want to have to lose sleep at night wondering if I left a door cracked, or an interior light on, or if onstar is phoning home and ruining my battery. Anyone used these on a C6 without issue?
2020 Corvette of the Year Finalist (track prepared)
C6 of Year Winner (track prepared) 2019
Originally Posted by Bigwebb
So I've been looking around to see what the latest and greatest in lithium battery technology is. I'm not too far from the 3,000 pound mark in my 08 C6 1LT, and I figured shaving 30# off of the Front end would just get me that much closer. I've looked at multiple options including Shorai, Odyssey, Braille, etc But I came across this that peaked my interest. Particularly because it has a built in safety for excessive discharge. This is ideal for me, as I typically drive the car every day, but don't want to have to lose sleep at night wondering if I left a door cracked, or an interior light on, or if onstar is phoning home and ruining my battery. Anyone used these on a C6 without issue?
Buy the Shorai - it's less than 6lbs and is around $300.
but if it draws down away from home, there you are. Plus if. Draws down to no charge, chances are it won’t recharge, so you’ll have to buy a new battery. One instance of this and you’re already at the price of the other battery I mentioned.
2020 Corvette of the Year Finalist (track prepared)
C6 of Year Winner (track prepared) 2019
Originally Posted by Bigwebb
but if it draws down away from home, there you are. Plus if. Draws down to no charge, chances are it won’t recharge, so you’ll have to buy a new battery. One instance of this and you’re already at the price of the other battery I mentioned.
I've accidentally run it down completely twice and after jump starting it it's been totally fine. I usually disconnect it while the car's in storage (it's a race car) but I've left it connected for up to two weeks without issue.
I've been using a 17# Deka for a few years in my '08 DD. They only have a 90 day warranty, since they're motorcycle batteries, but still strong enough to fire it up. $90 delivered. I do carry a jump starter anyway, although never needed it yet.
I've accidentally run it down completely twice and after jump starting it it's been totally fine. I usually disconnect it while the car's in storage (it's a race car) but I've left it connected for up to two weeks without issue.
I am going to install a Shorai LFX36L3-BS12 this week. I am waiting for the top posts to come in, then I will remove the factory battery and machine a direct bolt in aluminum plate so it will retain the factory style mounts...but better lol. This battery only weighs 4.55 lbs so its ultra light.
Agreed. I like the idea of the Shorai 4 pounder, because I daily the car. But I worry about it's reserve capacity, that first time I leave the dome light on.
Ok, so I had time at lunch to do the swap. Before I made any more mounts, I wanted to put the battery in and make sure it actually started fine and wasn't slow cranking or anything like that. After removing the factory battery, I weighed them both. As you can see, the Shorai saves 25 pounds, 9 ounces!!! Originally, I bought this battery for an off-road race car but I heard bad things about lithium batteries holding up to Baja style racing, so I never used it. This is why I already had the aluminum mount made. However, I ditched my aluminum mounts because the C6 hold down brackets are metal and I didn't want there to ever be a chance of arcing between the mount and the tie down posts. For now, I used high-density foam to make sure the battery was not sliding around. I will machine a delrin mount in the next few days to make sure everything is secure. I ordered some XS Power top post lugs for the battery from Amazon for $15. They sit a little low for the factory battery cable terminals so I made some 1/2" aluminum spacers and used longer bolts to put the lugs on. This puts the lugs on high enough to clear the battery. All I had was some 3/4" round bar so I will make some nicer 1" round spacers that match the diameter of the lugs for a cleaner look. The cables are tight in there so there is not much room to move around but I got it in and everything starts and seems to operate great! Time will tell as to the capacity of the Shorai vs the factory lead acid. Once I get the new mount done, I will post a final pic.
Last edited by k.miller959; 09-06-2018 at 05:39 PM.
Here are a couple of things from Shorai's FAQ's that makes me feel a bit better in regards to capacity. Obviously, time will tell. My car is a pleasure car but I also plan to use it on track so it will be the ultimate test for everyday user I suppose.
Q. How does the LFX "PBeq AHr" capacity rating compare to lead-acid Ahr ratings?
A. First, we need to understand that the primary job of a starter battery is to flow a large current (amperage) for a short time in order to start a vehicle. In order to do that efficiently, the battery must have low internal resistance. Holding all other considerations equal, the more capacity a battery has the lower its resistance will be -- thus it will be more able to crank a vehicle under high loads.
Lead-acid makers have therefore used AHr(capacity) ratings as shorthand to indicate cranking ability, rather than a real usable capacity. The lead-acid capacity rating itself is based on a complete discharge at a low discharge rate. Under actual cranking conditions they will deliver considerably less than spec capacity. And because lead-acid batteries begin sulfating when only a small percentage of the capacity has been used, and their internal resistance rises as they are discharged, the actual capacity which can be USED may be as little as 20% of the mfg. rating. Discharge in excess will not only damage the lead-acid battery, it may not allow proper starting as voltage sags.
Shorai LFX are based on a completely different chemistry. Not only do they have less than 1/3 the internal resistance per capacity than do lead-acid, they are also the ultimate "deep-cycle" battery. The internal "completely discharged" capacity of a Shorai LFX is 1/3 the rated "PBeq" capacity. For example, the LFX18 12V series have 6Ah cells internally. But the cells are capable of 80% discharge without damage and while retaining more cranking ability. As such, the USABLE capacity(or "reserve capacity") of an LFX18 12V battery is on or very near par with 18AHr-rated lead acid batteries, while providing superior cranking performance and a vast reduction in weight. The Shorai PBeq AHr (lead-acid equivalent) rating system therefore allows users to compare a very different technology from lead-acid, but on a close apples-to-apples basis when making a choice.
Q. How does the LFX "CCA" cold-cranking rating compare to lead-acid Ahr ratings?
A. CCA ratings another way that lead-acid makers have tried to convey starting power. Unfortunately, their typical spec is based on a "half-nominal-voltage" delivery. That is, at their CCA spec, you can expect 7.2V delivered, at best; and 7.2V isn't useful, as you won't start a vehicle with it...
In any case, CCA ratings aren't about actually drawing that much current from a battery. The typical vehicle which uses a 200A CCA-rated battery, for example, will only draw 45A~80A from the battery. What the CCA rating really intends to convey is how much voltage will be delivered. Higher CCA rated batteries will deliver more voltage at the same actual cranking current. Our LFX are CCA rated to deliver 9V for a 5-second crank at the CCA rated current. (in fact, our average voltage delivered will be even higher during a 30-second crank. But our CCA ratings are intended to indicate not only a measure of voltage at true cranking currents, but also proper usage, which lead-acid do not) At actual cranking currents - which are always well below CCA, LFX deliver up to two volts more than an equivalent-CCA-rated lead acid battery. Current alone won't start anything. It is the current multiplied by voltage that does the work (watts). In reality, this means that you can multiply the LFX CCA rating by 1.5x to compare to a Lead Acid battery CCA. For example, our 270A CCA LFX18 series provides about the same cranking voltage as a 405A-CCA-rated lead acid battery (from a quality lead-acid maker; some CCA specs we've tested on the cheapest lead acid seemed to be plucked from thin air).
3-year pro-rated warranty and your going to need it.
Hence lithium batteries loss charge each year, and life of one is only about three years to start with.
So the battery is kind of a scam to begin with, since your going to need to replace it in say 2 years, will only get created 1/3 of the cost since you used it, and the other 2/3's that you have to pay to replace it with other one, they are still making a profit on the battery.
So if you really want to lose the weight, then plenty of lithium batteries that will fit the bill for around $100, and when you do need to replace it in a few years, no big alligator tears like a school girl with a skinned knee come that time isntead.
3-year pro-rated warranty and your going to need it.
Hence lithium batteries loss charge each year, and life of one is only about three years to start with.
So the battery is kind of a scam to begin with, since your going to need to replace it in say 2 years, will only get created 1/3 of the cost since you used it, and the other 2/3's that you have to pay to replace it with other one, they are still making a profit on the battery.
So if you really want to lose the weight, then plenty of lithium batteries that will fit the bill for around $100, and when you do need to replace it in a few years, no big alligator tears like a school girl with a skinned knee come that time isntead.
I'd be happy with a lithium battery at the price point of the shorai that I knew I'd have to replace every two years. I bet the average length of corvette ownership is right at two years anyway. The problem is, that draw down to dead, and failure to charge back up, which is a risk from day one. Whether it's a boneheaded mistake, or parasitic draw, it's GOING to happen...
In the last 10 vehicles I have had, I don't think I have ever come out to a dead battery so I would not go as far as to say that it "is" going to happen. However, if the lithium batteries scare you then perhaps a good compromise would be an Odyssey PC 680 battery. It is a sealed AGM battery that comes in at about 15 pounds so you would have decent weight savings without the risk of not being able to jump your battery.
Well, I was going to make a mount out of delrin but I never got around to finding some. So I machined one from aluminum. Holds good and locates the battery square. You just have to use caution with the positive cable not touching the mount lol. I decided to keep the foam around the battery just in case.
Edit to add: So hard to tell from this photo, but the mount has a step on the underside that holds the battery square to the mount. On the front side of the battery, you can see a "notch". The bracket is stepped here as well to prevent the mount from sliding closer to the terminals.
Last edited by k.miller959; 09-19-2018 at 02:21 PM.
09-02-2018, 08:44 PM
Anyone Run the Antigravity RS-30 Lithium Battery
