My truck batteries (2x group 27) have finally degraded so much that they cannot start the truck after sitting for a day. I can replace them for about $200, or I can eliminate the batteries entirely and run a supercapacitor.
Someone talk me out of spending
$319 on this! The auction is for 6 used 3000 F capacitors with balance circuits. I think I can get the parasitic drain on the truck to 5mA or less, and I have a solar charger in it already.
My only hesitation is that a powerful fuel lift pump runs when the ignition is switched on, and air intake heaters kick on at 180 amps for 8 seconds when it's very cold outside. After all that, the starter can draw up to 400 amps for 3 seconds.
Do you think the capacitors are up to the task of starting when it's cold out? Ideally I'd like to eliminate the battery altogether, but I suppose I could run a smaller battery if necessary.