Ultra-light starting batteries
 

If a guy needed a battery anyways...maybe one of these Braille's would fit the bill. At a mere 6lbs and 'only' $139....worth the weight savings?
(I just fired them an email asking if there was any reason they couldn't be run on a factory charging system)

Scroll down a bit for specs.
https://www.brailleauto.com/productca...17&idproduct=2

That's pretty cool. Considering how small it is, that's not a terrible price either.

Don't do it
 

The problem is that you'll be buying a new one every year, if it lasts that long. The smaller the battery capacity, the larger percentage of that capacity you'll use for a single start. The percentage of total capacity used in a discharge cycle determines the total number of cycles you'll get, and the number of cycles decreases rapidly with deep discharges, e.g. leaving the lights on.

This battery has about 15 minutes of reserve, whereas a normal battery has around 90-100. So, you're draining the smaller battery's capacity about 6x as much as a normal battery's with every start. Not to mention that if you're coasting around with the lights on and engine off, it probably won't start at all unless you bump start it.

Dunno about you, but I don't think I'd make up a ~35 lb weight savings in gas cost at ~$140 a year.

Personally, I'd go the other way and get a D35 Yellow Top Optima...it'd last longer than a standard battery, weigh about the same and allow you to coast around in the dark as much as you'd want.

Just to be a spoiler here - note the electrical specs, from the "more details" page:
https://www.brailleauto.com/productca...duct=2#details

One might be able to buy a garden tractor battery of similar capacity for a lot less money. The Braille's 32 deg. F, cold cranking amps and reserve capacity are a lot lower than the numbers for typical automotive batteries. Suitability would probably depend on your local temperatures and how much reserve you like to have.

Pulse Cranking Amps: 527
Cranking Amps @ 32 F: 283
Cold Cranking Amps @ 0 F: 210
Reserve Capacity: 20 minutes
Capacity (C/20 rate): 11 amp hr

I've heard of people using lawn tractor batteries, a couple of the turbo mopar crowd have them to reduce race weight.

Is Canada warmer then I think it is? to quote their web site:
"Not Recommended For:
Cold Climates
Long Term Storage
Large Displacement Motors with High Compression"

the colder it gets the slower the chemical reaction inside the battery, reducing it's effective capasity, thus the cold cranking amps number, but that number is only 0-F as it gets even colder the number drops off even more.
Their next heavier battery MIGHT work if you live in that warm part of Canada, otherwise I would highly recomend going with their heavy duty battery of course at that point you are getting in to 15lb and 21lb batteries, but they do say that their largest will work when cold.

Having personal experience with the Hawker SBS lightweight battery, I'd shy away from this for the reasons Bruce pointed out. You won't get far if you do any amount of EOC'ing requiring the battery for restarts.

I don't anticipate doing much, if any, EOC'ing...but the battery cycle limitation makes sense. Good point.

As for winter...I'm not sure what would be ok at -20. Maybe 200 CCA would still spin a small 4cyl. (but it still comes back to the high percentage of drain I suppose)
My V8's always had 800-1000 CCA and even at -30, they'd spin the motor like a top.

Tractors eh?

I just put a 435cc garden tractor battery in my CRX. It turns it over without any problems. It cost me $25 at autozone and another $5 for the terminals.

In So Cal, I don't have to cold start issues and I've heard people running these for a couple years without any problems

Fuel is about 8 lbs / gallon. Leave the tank at half or less if weight saving is the issue.