sherff

Hello,

I just had my out of province inspection done on my 99 type R a few weeks ago and they told me that my battery was really shitty, and sure enough after i drove it home (800km) and let it sit for 2 days (with nothing on) it didnt have enough juice to start and it looked like some acid was coming up from the vents.

Normally i would just go pick up another battery, however since the ultimate goal i have for the car is to get the weight down to 1 ton (2200lbs) or less and i am thinking of doing some engine mods in the future (v mount intercooler after PFC, Injectors and boost controller) so a smaller and lighter battery would work wonders for me.
My Questions are:
-what are the specs for the stock battery (the stickers on mine are Japanese)?
-what specs should i be looking for on a Lithium battery for use in a car only driven in the summer?
-what thoughts you have about lithium ion batteries as a whole? and
-what brands/options are there?
-what price range should i look at to not be getting ripped off price wise or quality wise?-I have the number $600 in my head, would that be adequate to get a decent quality one that will last for a long time (battery will be removed and stored inside during winter)?

I have found a few on Jegs, and after a bit of research found a company called braille that makes lithium ion batteries(the braille ones are a bit on the expensive side of things) any other brands or places i can buy them? Canadian locations that ship would be great too since i am in fort mac which is 400+ km away from the rest of civilization.

Finally am i allowed to post this in multiple sections? i feel as though i would get a broader range of feedback if i also posted this in the audio/interior/exterior, general tech, canadian forum and 3rd gen specific forums aswell

misterstyx69

iTrader: (142)

Your post count is sufficient o post in other sections now,so you can freely do that if you desire to.(actually encouraged to,as NEW guys can only post Tech questions here until they gain sufficient posts to post elsewhere.)

Braille is the alternative to a smaller lightweight battery.,.also DEKA.

The downfall of a small battery though would be that if you have a hard time starting the car you can kiss the Cranking amp time goodbye as it only allows you so much power to start the car.After that you may as well push it or call a tow truck!

* I saw a "thing" on Capacitor type batteries on Youtube I believe..you may want to look at it.I found it very interesting.

ACR_RX-7

iTrader: (1)

I personally have little experience with LiIon batteries under the hood, but the benefits are that they are ultra light and have no "memory" like other batteries. (meaning they can handle a deep cycle) The LiIon batteries in auto use are ultra expensive, and IMO are not really anything you need for street use, even in the summer only. I wouldn't spend more than $300 on a battery and there are weight savings that can be found elsewhere.

That being said, I would install a smaller group size than what the RX-7 comes with, like a Group 51 out of a Honda. They produce around 450-550 CCA and can start an RX-7 fully charged. The reason the RX-7 battery is so big is because of cold start and longer cranking times. There is rather little actual peak current draw when cranking a rotary, it's more of the reserve capacity that you are looking for. I have had good luck with AGM batteries by Optima. I have heard GREAT things about the Braille batteries though.

It's not just Cold Cranking Amps you are shopping by either. Look for a battery with a very high reserve capacity. Reserve capacity is the amount of time a battery can handle a load. It is a time measurement that explains how long a fully-charged battery can deliver 25 amps of current in an 80°F-environment, before the battery is discharged down to 10.5 volts. (found on Optima's website)

I would ignore Pulse Cranking Amps. It's a made up value not recognized by the BCI, but it is a measure of how much amperage it can flow in a single pulse at full load. Between manufacturers, they will determine how they measure PCA.

I have a couple of batteries that I feel would be suitable:
$250
Braille Battery#147-B2317
Advanced AGM Lightweight Racing Battery
17 lbs
6.8'' L x 4.0'' W x 6.1'' H
Cold Cranking Amps: 475
Cranking Amps: 770
1191 (PCA) Pulse Cranking Amps
Left Side Positive
45 minute Reserve Capacity

$200
Optima Batteries 8073-167-FFP D51R YellowTop Dual Purpose Battery
12-Volt, 450 cold cranking Ampere
size: 9-5/16" x 5-1/16" x 8-15/16" tall,
weight: 26 pounds, SAE post
Reserve capacity of 66 minutes

$600
Braille Battery GU1R - Braille Green-Lite Lithium Ion Racing Battery
Full Charge Voltage: 13.2
Lithium Amp/Hour (LAH): 39
Reserve Capacity: 32 minutes
Maximum Constant Amps: 150
Pulse Cranking Amps (PCA): 947
Cranking Amp Replacement: Up to 800 CCA (Racing Use)
7.68'' L x 5.13'' W x 7.13'' H*

With ALL of these batteries, you will NEED a special charger capable of charging these. A regular battery charger WILL cook an AGM or LiIon Battery. AGM stands for Absorbed Glass Mat. Basically it's fiberglass impregnated with the electrolyte. Gel cell batteries are of a similar type, but Gel is a thick acid. Braille sells their own chargers. I do not know their restrictions on their LiIon batteries, so I would ask them.

sherff

Right on thanks for pointing me to that Braille one, I was browsing their site befor and had no clue as to what series I should be looking at or the specs I would need. Do you by chance know what's special about that charger, as in would I need to keep it hooked to it any time I'm not driving? Or is it just a charger that automatically shuts off once nominal voltage is hit?
I've heard that in the last couple of years optima quality has gone to **** so I've been avoiding them

BLUE TII

iTrader: (9)

I have the biggest Shorai motorcycle Lifepo battery in my ASP FD.

It weighs 4lbs and is quite small.

I recently pulled the battery out to put it on the Shorai charger as it had been sitting a little over a year and it charged for a couple minutes and went into storage mode.

Very little storage discharge.

It does have limited capacity.
I left my AC/ignition switch on to keep the radiator fans running on high with the car off in grid at one race and got caught up talking for about 15minutes and the battery was flat.
Duh, I should have just used the turbo timer!

misterstyx69

iTrader: (142)

punch this in on Bing:capacitor battery for car/youtube

Look at first video

sherff

Yeah I watched one where the dude had a bunch of chickens running around, is that the one? Anyway that is ******* insane and awesome, might try it just to **** around with if I can find somewhere to get super capacitors

misterstyx69

iTrader: (142)

Chickens were actually Hondas with feathers..lol!(that tends to happen once they get a "big *** wing" installed..then SEE a RX7 done up to the Nutz!)

rcpython59

Look into other types of lithium batteries like Lipo and life. Lipo is probably the best but will burn your children if you don't maintain it. Has to stay between 3.2 And 4.2 volts,avoid extreme temps,reverse polarity or shorting out as that is usually instant death. But the up sides are incredible amperage capabilities, best you can find without going to capacitors,light weight,very high energy density,don't get hot.

Life is another story, they are much safer,but a bit less energy dense,closer to nimh in terms of size,but still lighter. I am not sure of this,but I believe they have higher amperage capabilities too. You still have to take the same precautions as with Lipo,but when something bad happens it shortens the life,doesn't cause instant death. It also has an oddball voltage of nominal 3.3 vs 3.7 of Lipo and lion.

Also,don't be afraid of lipos from what I said, they're perfectly fine if you treat it with care,I've been using them since I was 12 and have yet to have anything go bad with them.

ACR_RX-7

iTrader: (1)

The chargers that are available for AGM batteries are really not that expensive. A good Battery Tender or a Marine Float charger should do the job. I personally have a Snap-On EEBM500 battery maintainer/charger that works extremely well. You are looking into the $50-150 range for a good maintainer/charger.

At my work, we have an awesome wheeled battery charger that can handle standard, AGM, and Gell Cell batteries. It's a PL3730 Solar Pro-Logix charger that retails for about $300. I personally would go with a float charger, like the Snap-on one that I have. It takes a long time to get a full chage (overnight) but is very well worth it. It has kept my motorcycle battery at full strength all year.

The Braille batteries that are LiIon are a different story. I don't have a tone of experience with LiIon batteries outside of power tools, but I would buy the charger that they sell. They range from $100-$400 and the price differences are due to charging amperage. The more you spend, the faster you can recharge.

sherff

Yeah my work has a charger that can do constant current or constant voltage 12 or 24 volt rangeing from 0.1 to 15 amps and has a built in timer so I'm sure Im good for that lol
I may try and make that super capacitor boost pack from the video just for fun aside from the actual battery too lol, we have mill at work so I could make a half decent case out of Teflon or something too

ACR_RX-7

iTrader: (1)

The thing to look for in a charger is that it has the capability to do AGM. It's not just about the amperage, it's the voltage being fed into the battery. Overcharging a battery, even at 15 amps can kill it. AGM chargers are micro-processor controller and don't only run off a timer.

sherff

yup thats what i said, the charger at work is an aircraft battery charger capable of doing constant current or constant voltage (constant voltage is what a alternator does), on constant voltage 14 volts is applied at whatever current, then as the battery approaches the voltage the amperage drops off till its even with the charger

ACR_RX-7

iTrader: (1)

Good stuff. I did look into the capacitor battery and I was very impressed. There is an EV project that was recently completed on an RX7 where this guy used individual LiIon cells. Here is a link to his battery build.

Zero Emission Vehicles Australia