New 12 volt Battery , weighs just 3 pounds .

[TobyB]

Steve,

that's a very good idea.

I'd add a 10lb extinguisher

to the mix!

Let us know how it does.

t

[LimeySteve]

I just drove home , 25 minutes & all is well, battery cold to the touch inside the ammo box, no surprises , just the normal drive home , I'll keep an eye on the system & report any changes. I was so pleased to come up with the ammo box idea , I've had that one for about 5 years, it's so small I never thought I'd find a use for it.They are so cheap on ebay too , but it almost doubles the weight of the battery

[Pierre]

I have been using a Miata battery in my E36 318ti with S52 motor with great results. Yes, it's more like 13 pounds and not 3 but it's lead acid, predictable, cheaper and a lot lighter than the 40 lb stock battery.

In my case, it was a space issue more than a weight problem. If I was chasing to lose 10 pounds, I can find a lot of places where I could do so, starting with my mid-section.

[LimeySteve]

Follow up on my Lithium battery experience, All seemed great , easy start , bright lights etc etc , no explosions or burnt down car, then this morning after sitting for about 10 days the battery was dead , 2.2 volts !!!!!!!!!!!!!!!!

 

So for that reason I'm out , it was worth the try but for a daily driver or occasional driver , not yet in my opinion. If I had a dedicated race car & would disconnect it after each race etc then I'd be all over it , hopefully soon but not yet on my experience.

 

Luckily I kept my lead acid heavy weight in the trunk disconnected so recommision was easy & it still had 12 volts in it