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)
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.
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.
I've heard of people using lawn tractor batteries, a couple of the turbo mopar crowd have them to reduce race weight.
I remember The RoadWarrior..To understand who he was, you have to go back to another time..the world was powered by the black fuel & the desert sprouted great cities..Gone now, swept away..two mighty warrior tribes went to war & touched off a blaze which engulfed them all. Without fuel, they were nothing..thundering machines sputtered & stopped..Only those mobile enough to scavenge, brutal enough to pillage would survive. The gangs took over the highways, ready to wage war for a tank of juice
Is Canada warmer then I think it is? to quote their web site:
"Not Recommended For:
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.