Lightweight Battery Project

[inuvik]

A friend of mine had a Delorean with a fake flux capacitor along with a bunch of garbage bolted on the outside of the car. All it did was add wind resistance/weight and slow the car down.

Obviously the flux capacitor wasn’t producing 1.2 jigawatts. He could have cancelled the effect of the extra wind resistance by slapping some “turbo” decals on his Delorean. That’s a 50HP upgrade instantaneously. Which is why I haven’t done either mod. I can barely control my Mirage’s monstrous OEM 74HP. Anything more would just be downright dangerous.

[Eggman]

OMG this is absolutely nothing short of priceless in so many ways.

[AssassinTime14]

Hey guys what would be a recommendable battery size/wattage for winter & summer conditions then?

[poorman1]

Group 24 800 cca / 1000 mca

[Eggman]

Hey guys what would be a recommendable battery size/wattage for winter & summer conditions then?

For winter, the biggest you can fit. For summer, the same.

Another way to phrase it might be daily driver v. competition. And the answers would probably be similar
Daily Driver: stock size or biggest you can fit
Competition: smallest size you can fit and/or use a jump start!

Why would anyone want to go with a smaller battery for a daily driver? It would experience more stress on engine start, leading to an early demise and possibly getting stranded.

[Mark]

Hey guys what would be a recommendable battery size/wattage for winter & summer conditions then?

The standard size battery for the Mirage is a group 35. You can purchase various levels of group 35 batteries. More expensive ones are going to give you slightly more amps, CCA, & longer warranty.

The Mirage (1.2L engine) has a decent size battery for a small car. My 2011 Subaru Forester (2.5L engine) takes the same group size battery. Since I haven't had any battery issues with my Forester, I wouldn't expect to have any with my Mirage.

Since the Subaru Forester is quite common, these batteries are always in stock at most places. I'm sure a number of vehicles use this size battery, but I haven't researched that. I just known my two vehicles use the same one.

[stevedmc]

For winter, the biggest you can fit. For summer, the same.

Another way to phrase it might be daily driver v. competition. And the answers would probably be similar
Daily Driver: stock size or biggest you can fit
Competition: smallest size you can fit and/or use a jump start!

Why would anyone want to go with a smaller battery for a daily driver? It would experience more stress on engine start, leading to an early demise and possibly getting stranded.

Amen.

[Loren]

Short term (very) feedback:

I ordered this battery from Amazon. I never even checked the voltage on it, much less put it on a charger. I just built a bracket for it, and put it in the car.

Today, we put a new engine in the car. So, the first thing that battery had to do was spin the engine with the fuel injectors unplugged for probably about 45 seconds total in 5-10 second bursts. No idea how long it had been since the engine was last run, wanted to be sure there was oil pumping through it before starting.

Then we connected the injectors, and it fired right up. We hadn't put the radiator in yet, this was just a test start. So we shut it off after the oil pressure came up.

Then, after we had a celebratory lunch, we started the car again to let the clutch out, and run it through some gears before buttoning everything up. (would hate to find that we did something wrong with the clutch and have to take EVERYTHING back apart again) Didn't run it for more than a minute or so, still no radiator.

After buttoning everything up, we started it up and went for a brief test drive around the neighborhood.

Then we fixed some stuff, and went out for a longer drive.

Then, because there was a significant left/right camber mismatch, the steering wheel was way off-center. I didn't feel like taking the wheel off and readjusting the camber. (tires are dead, going to be replace very soon, so not worried about it, will fix it later) Wanted the wheel straight, so did a toe adjustment. Which inevitably means several toe adjustments to get it right. Another 4 starts with 2-block drives in between each one.

And lastly, I moved it out of the driveway to get my wife's car back in the garage.

We did the equivalent of maybe 16 starts today most with little or no recovery time for the alternator to charge the battery. The car cranked just like it always does every single time.

It's very rare that I abuse a battery that much in a single day. Usually, if I'm driving, I'm out for trips of at least 15 minutes... usually more like 30-45. Even on autocross days, there's not a lot of restarting without charge-time between starts.

So far, so good!

[Fummins]

Never heard of a BTTF. Is that like a flux capacitor?

[01-7700]

I used a 200 amp lawn mower battery in my Mirage for a week after I ran my battery down. Worked fine.