Log in

View Full Version : LiFePO4 batteries ?


Croustibat
01-11-2013, 07:21 AM
So ... my S13 battery died, again. My fault again for not using the car enough and not charge it ... But i need to remove the intercooler cold pipe to remove the battery, and that really is a pain. I decided to move on and get a very small battery, like an odissey one.

Then i came across these lithium batteries. They do look appealing; very lightweight, same price as an odissey battery, and seem to fit cars that dont get used so often, amongst other things.

I wonder if some people here are using them ? Please chime in if you do, or know something about these.


This is what i have learned so far:

Pros:
Weight/price ratio. Fancy a 200$ / 3lbs battery ?
supposedly 10x more life cycles than lead batteries.
Voltage does not drop until battery is out (like other. Empty battery is at around 12V, full is around 12.8/13V)

Safe, environment friendly and dry cells: no need for a battery box.
Very low internal resistance => very good at starting cars, and very low losses when not used. also, very fast at charging ... 30mins charge. Then you have to wait 30mins for it to cool... Way better than my 24h slow charger.

Small, and can be installed in any position.

Cons:
it needs some electronics, and not a lot of suppliers fit it on the battery.
Their ratings are fake. divide Ah by 3 to get the real rating.
PCA rating is a fake CCA too. Shorai started these fake ratings to compare the batteries to a lead one. Nearly everyone followed. If you see a 20AH battery for less than 600$, it means its a faked rating.
terminals are not car terminals.
mostly used on bikes, powerboats, skidoos. Not on cars.


Techs:
It looks like there are 2 types of cells mainly, cylindrical and prismatic ones. Prismatic is supposed to be better.

You can get your own cells and electronics from ebay, and build your own. That will still be chinese ebay stuff though ... i would not use that.


You really need that electronic board, called BMS, IN your battery. Some manufacturers sell their battery without, then put one in the charger. That is a bad idea really, as the battery is unprotected when used in the car. The BMS is not cheap, i think i saw 60$ on ebay. They protect from over and undervoltage, which both kill cells, and they balance cells. Some also limit the max discharge current. If you are getting that kind of battery, get a BMS that do all of that and have it fitted at the battery, not in the charger. Unless you like buying new batteries often.






Makes:

Ballistic:
Someone on sxoc was using an "Evo2" 16cells one. Seems to work. The 12cells are used to power kawasaki vulcan 1500cc custom bike. These dont include the electronics.

EarthX:
Seen some comments around, looks legit. Assembled in USA from chinese parts. They do however include the electronics (balancing, under/over voltage protection, current limiter). I may go for that brand. They do a 24AH (read 7.4AH) model which i think would suit my CA18DET. There also are 18 and 36AH versions. I still dont understand what the "C" or "D" at the end of their references means.

Shorai:
dont know much.

XSpower:
not the one that sells crap i believe. These ones have been the first, but their price range is unbelievably high.



If you feel i am missing something, please comment.

memphis180sx
01-11-2013, 08:01 AM
The smaller battery the less charge it will hold over time

fliprayzin240sx
01-11-2013, 04:21 PM
Why dont you just get an optima battery and get a relocation kit to the trunk? I got a drain small drain on my car and my car would die if i dont start it atleast once a week. After changing to an optima yellow top, I've had the car sit for almost 4 weeks on a charge and had no issues firing back up.

Croustibat
01-11-2013, 05:06 PM
Because i dont want to relocate the battery to the trunk, or anywhere else. It will stay under the hood. Maybe it will go where the ABS pump was but thats it, no wire hacking.
That and yellow top optimas are not meant for starting cars if i remember correctly, you want a red top for that (that is written on their website)

fliprayzin240sx
01-11-2013, 11:20 PM
Figured you're gonna say that...post up your engine bay, I'm curious how much space you have and how you got your current battery wedged in there.

Croustibat
01-12-2013, 06:43 AM
I would have posted if i had one, but this thread is about LiFePo4 batteries, not about my engine bay ;)
I have a euro S13, they come with a CA18DET as standard. fmic piping kits go through the battery tray, so i had to remove the windscreen washer filler, fit a small battery and push it to side. It is a pain to remove, and an optima or any regular battery would still cause the same problem.

OutToWinPAHC
01-12-2013, 07:02 AM
Why dont you just get an optima battery and get a relocation kit to the trunk? I got a drain small drain on my car and my car would die if i dont start it atleast once a week. After changing to an optima yellow top, I've had the car sit for almost 4 weeks on a charge and had no issues firing back up.

This I got a tiny battery in my All-trac and if it sits for a week it's dead, I keep a tender on it, but I wish I just relocated it

epedomic
01-12-2013, 08:30 AM
why not get a Braille battery and perhaps a voltage modulator?

They sell the standard ones (9lb-15lb) for around $150, while the carbon fiber ones (6lb-11lb) are around $220. A little pricey but they definitely go a long way considering that their specifically built for street or track use.

heck i wouldnt even throw a modulator on these, i have an nrg one on my duralast sitting in the truck but once i get the cash im getting a lightweight battery back to the front.
its best to reduce the weight on one side than to add weight on the other for balance.

KoukiMonsta
01-12-2013, 02:48 PM
I too have done a bit of research on these batteries as I am familiar with them in non automotive applications. Issue is there's not a lot of info out there since these are not common in cars, mayb it will catch on.

I've been debating running something of this sort in a weekend/track whatever I don't drive it often type car. They won't hold a charge for long, BUT you can let them die and charge them repeatedly, unlike your standard battery. I like this cuz that means I won't be buying a new one..mayb ever? Or for like 10 years type thing.

Ok so yea it dies often, I'm not talking in like a day or an hour though.. Say you wanna drive the car, throw the tender/charger on for a bit. Boom crank it up and alternator gets everything good to go in no time...

I'd like to see more input on LiPo and not.."get a Braille" blah blah. They really are a neat technology.

Croustibat
01-13-2013, 02:13 PM
This I got a tiny battery in my All-trac and if it sits for a week it's dead, I keep a tender on it, but I wish I just relocated it

why not get a Braille battery and perhaps a voltage modulator?
[...]

Please guys. Read the thread title. Does it read "find a battery solution for my S13" ? No. It reads "LiFePo4 batteries". For now i want info on these kind of batteries, and i will make a decision based on this. But i dont want to be selfish and keep that to myself, so i decided to create this thread, so that other people could make an informed decision when the time comes to change their battery.

I see no point in spending 200$ to relocate a battery (i wont do it ghetto style so that is the kind of money involved), and then get another battery for another 200$, hence the "i wont relocate it".

So please, post only about this kind of battery.


Kouki monsta > Lipos are Lithium polymers, aka lithium ions. Not lithium iron phosphate. It is yet another tech, these have a 3.2/3.3V per cell. Basically it is quite similar to lipos, but they just die if you under/over load them, they dont explode like lipos do. I already lost an R/C helicopter due to lipo failing, and i really dont want that in my car (basically my controlled helicopter suddenly became an uncontrolled fireball)


So back on the subject.
I have seen some golf kart batteries with these batteries, but not much more.

KoukiMonsta
01-13-2013, 02:22 PM
Please guys. Read the thread title. Does it read "find a battery solution for my S13" ? No. It reads "LiFePo4 batteries". For now i want info on these kind of batteries, and i will make a decision based on this. But i dont want to be selfish and keep that to myself, so i decided to create this thread, so that other people could make an informed decision when the time comes to change their battery.

I see no point in spending 200$ to relocate a battery (i wont do it ghetto style so that is the kind of money involved), and then get another battery for another 200$, hence the "i wont relocate it".

So please, post only about this kind of battery.


Kouki monsta > Lipos are Lithium polymers, aka lithium ions. Not lithium iron phosphate. It is yet another tech, these have a 3.2/3.3V per cell. Basically it is quite similar to lipos, but they just die if you under/over load them, they dont explode like lipos do. I already lost an R/C helicopter due to lipo failing, and i really dont want that in my car (basically my controlled helicopter suddenly became an uncontrolled fireball)


So back on the subject.
I have seen some golf kart batteries with these batteries, but not much more.

oh okay, my mistake. ill do some reading. i am familiar with the whole fireball thing and its quite scary!

dirtdiggler666
01-13-2013, 04:31 PM
I can give you a hint and say if you want one you have to build one yourself or pay around 1k the ones for motorcycles ect will not last.