Will
Will SuperDork
1/9/15 10:46 a.m.

The Odyssey PC680 (14 pounds) in my 99 Z28 finally died. Since it's a dedicated autocross car, less weight is always good. I've used a Braille 14115 (10 pounds or so) in my Supercoupe since 2008, but that car has less displacement and compression than the Camaro. Still, that Braille is the same as the $75 Deka ETX14, which makes it tempting.

So how small can I go? The car sits on a tender when not in use, so as long as it will start the car 6-8 times at an autocross, that's good enough. The Deka ETX9 is the same price and lighter, but I'm not sure it's stout enough for the LS1. Lithium stuff like Shorai is interesting, but not sure it's up to the job.

Thoughts and recommendations?

rcutclif
rcutclif HalfDork
1/9/15 10:48 a.m.

If its really autox only and you are really want the small battery, have you thought about bringing a big battery (jump pack) and then going with the smallest possible?

clutchsmoke
clutchsmoke Dork
1/9/15 10:53 a.m.

For a 6 pound difference I think I would save the hassle and just go with the ETX14.

84FSP
84FSP Reader
1/9/15 11:00 a.m.

I have the 11lb Deka (don't remember the name) and it works pretty well for a non-daily that is primarily an autox toy. I tried the 6lb battery but even for a GTI with minimal draw it wasn't enough. I roll with a charger pack at all times and would absolutely not run anything under a factory Cranking Amps battery in a daily.

16vCorey
16vCorey PowerDork
1/9/15 11:07 a.m.

I've seen at least one car (online, not in person) that was using a lithium ion battery that was really, really small. We have a new lithium ion jumper pack at work that's really small and will jump start a car, but it's only good for a couple jumps before it's dead. I would think that would work as long as you're not starting and turning the car back off over and over in quick succession.

Keith Tanner
Keith Tanner MegaDork
1/9/15 12:01 p.m.

The lithium stuff from Braille is creepy light. Like "I think they forgot to put the battery in the case" light.

For a dedicated autox car, I like the jumper box idea.

bigev007
bigev007 Reader
1/9/15 12:53 p.m.

I've been curious about thisone for a while. Wondering how it would handle my 328. 1.76lbs jawdrop

Will
Will SuperDork
1/9/15 1:55 p.m.
rcutclif wrote: If its really autox only and you are really want the small battery, have you thought about bringing a big battery (jump pack) and then going with the smallest possible?

I don't think I want to have a battery that requires a jump pack. I drive this car to events, and I don't want to have to jump it every time I stop for gas.

That Battery Tender brand lithium one is interesting. It has more CCA than both my current Odyssey and Braille.

16vCorey
16vCorey PowerDork
1/9/15 1:58 p.m.

Here's a test of three different li-ion jumper boxes.

http://www.cnet.com/news/pocket-sized-jump-starters/

FWIW, the one we have at work is the PowerAll. While the review says it's good for 20 jump starts on a charge, that must be 20 cars that just barely don't have enough power to start on their own, because it will only start 2, maybe 3, if the batteries are totally dead.

bigev007
bigev007 Reader
1/9/15 2:02 p.m.
Will wrote:
rcutclif wrote: If its really autox only and you are really want the small battery, have you thought about bringing a big battery (jump pack) and then going with the smallest possible?

That Battery Tender brand lithium one is interesting. It has more CCA than both my current Odyssey and Braille.

They have bigger ones too, they're just way more money.

mad_machine
mad_machine MegaDork
1/9/15 3:45 p.m.

interesting thought. It takes more power to crank a cold car than a hot one. Get the smallest and lightest battery you can.. and just use the jump pack to start it from cold?

Once the engine is good and hot, it should not take more energy to restart it

Will
Will SuperDork
1/9/15 3:52 p.m.

Please remind me of the problem with charging/overcharging lithium batteries. Is that still a thing?

Kenny_McCormic
Kenny_McCormic PowerDork
1/9/15 4:03 p.m.

In reply to Will:

This is what "protected" lithium batteries aim to avoid, with a little circuit on each cell to cut the connection if voltage or current exceeds a limit. FWIW, lead acid is capable of thermal runaway as well.

mazdeuce
mazdeuce UberDork
1/9/15 5:37 p.m.

I ran a lithium battery that was something like 1.1 lbs in the Mazda2 for a bit. I never had a problem with it. Stayed cool, always started the car, never lit on fire. I ended up leaving in in the garage last winter and it probably froze. This spring is was noticeably puffy and quite dead, so I pitched it. I'm not sure how well it would have faired had I continued to use it off and on and treat it well. I never charged it with anything other than the alternator when it was in the car.

84FSP
84FSP Reader
1/9/15 5:42 p.m.

To clarify the times I've needed the jumper were all hot start related with long times cranking. The rabbit still starts much harder than it should and may end up needing a mod to the cold start setup.

carbon
carbon Dork
1/9/15 8:52 p.m.

Ive got 3 shorais, Had a couple for several years now, they all rock. Cant say enough good things about these batteries.

Will
Will SuperDork
1/10/15 8:54 a.m.

I think I'm inclined to try that Battery Tender lithium one posted earlier. If it somehow turns out that it won't work in my car, I'm sure I could sell it locally to a 4-cylinder owner.

chaparral
chaparral HalfDork
1/10/15 2:33 p.m.

Zippy LiFePO4 8400. $85, 1 kg, 250 CCA - but CCA above 12V so it'll start a Honda RC51 or a GM LS1. You will need to externally charge it once and balance charge it annually. Lithium Iron Phosphate batteries do not set themselves on fire - they may burn if torched. Mount it as close as you can to the starter, so that you don't end up with a battery cable that weighs more than the battery.

TIGMOTORSPORTS
TIGMOTORSPORTS Reader
1/11/15 6:20 a.m.

In reply to Will:

How did you like the Odyssey?

http://www.batterymart.com/p-odyssey-pc680-battery.html?gclid=CNPUm7H1i8MCFfLm7Aod1XgAcg

My 78 Camaro will be returning to some bracket race duty this spring, after sitting for several years. I've been looking at small batteries also (Dynabatt, Braille, etc)

mazdeuce
mazdeuce UberDork
1/11/15 7:26 a.m.
chaparral wrote: Zippy LiFePO4 8400. $85, 1 kg, 250 CCA - but CCA above 12V so it'll start a Honda RC51 or a GM LS1. You will need to externally charge it once and balance charge it annually. Lithium Iron Phosphate batteries do not set themselves on fire - they may burn if torched. Mount it as close as you can to the starter, so that you don't end up with a battery cable that weighs more than the battery.

What do you use for a charger/cell balancer? I didn't own mine long enough to get a proper charger. I'm planning on getting another one and would like to do it properly this time.

Will
Will SuperDork
1/11/15 7:43 a.m.
TIGMOTORSPORTS wrote: In reply to Will: How did you like the Odyssey?

Considering I bought it used for $20 from a friend who had it in his 944 road race car for years, and it lasted me over 3 years, I'd say I got my money out of it.

Admittedly, it was borderline for the car. One time we left a camera/data acquisition setup plugged in for several hours and it drained the battery to the point we had to push start the car. And this was a bit goofy, but after installing it, the trip odometer reset every time I started the car. Those were the only real problems I ever had with it, though.

Will
Will SuperDork
1/13/15 4:18 p.m.

This occurred to me: is there anything better to do with my old Odyssey than take it in for the typical $5 credit at Advance?

Will
Will SuperDork
1/14/15 8:23 p.m.
bigev007 wrote: I've been curious about thisone for a while. Wondering how it would handle my 328. 1.76lbs **jawdrop**

I just ordered this one. Amazon has them for under $110: http://www.amazon.com/gp/product/B00F9LPJ8S/ref=od_aui_detailpages00?ie=UTF8&psc=1

Ojala
Ojala HalfDork
1/14/15 11:26 p.m.

In reply to Will:

Some scrap yards will give you $10. Anyone you know have kids with Power Wheels? They do awesome plastic wheel melting burnouts.

I think I drove for 3 years on a garden tractor battery before I bothered to replace it with a lithium. Never have had a problem with either one.

Will
Will SuperDork
1/21/15 5:32 p.m.

My lithium battery showed up today and it's comically small. According to my scale, it's 1 lb 13.4 oz compared to 14 lb 3.4 oz for the old battery.

It started the Camaro with no hesitation. Current temp is 53°, so it's not as if I'm in the great white north, but still, I'm impressed. I basically started my car with an RC battery. Technology is cool.

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