So, I needed to install a couple power receptacles (cigarette lighter plugs) in the bed and thought it would be prudent to install a second battery
After reading a bit on this forum, I ordered a Painless 40120 Digital Power Manager from Summit Racing. It arrived promptly and I was ready to start the installation yesterday after work. When I openned the box I noted that the only thing in the box was the module and the wire bundle. There was no hardware, connectors, bolts, heat shrink, or electrical insulating boots for the terminals.
So, in the interest of getting this project done this weekend, I headed to an autoparts store looking for these items. O'Reilley = no luck. Pep Boys = no luck. Electronics store = heat shrink & connectors, no boots. West Marine = boots and large connectors. 2 hrs and 20 miles of driving in rush hour in L.A. and the associated gas, I had my hardware. I figure I'm $8 in gas and about $20 in parts into this, plus the $200 "Painless" part.
Aux battery installation. I used a factory clamp and bolt $6-7 at the dealer.
I tied from the Painless module to the fuse block on the firewall, because it was more convenient than tieing directly to the battery.
Trimmed the fuse cover to allow for the cable out the top left.
The kit comes with enough wire to run 5 ft from the aux battery to the module then another 5 ft to of cable to the main battery. I wanted the module behind the main battery. That took 10 ft of cable from the aux battery. I decided I'd bump the cable gauge from 6 ga to 4 ga for a 10 ft run. $30 worth of cable at West Marine and some cable ends
My location for the green flashing light...for now. I was finding it a pain to find a firewall penetration to run the wire so I just put the light outside in the plastic corner trim of the windshield. Short wire run, easy to replace the corner trim.
So, it was almost $200 for the "Painless" module. About $125 for a DieHard online w/tax. Probably another $75 in cables, hardware, etc., plus the countless trips to stores. Call it another $100. So, maybe $400-425 for this installation.
I hope this Painless thing is trouble free and an works when needed. But, by its very nature of design, you will likely never know if you've drained your main battery and the aux battery provides an assist to starting the truck. This system is not supposed to let a slow current draw drain the aux. Normal slow current draw should drain the main battery, then, when a large (starting) load is encountered and the main is unable to provide all the current, the smart circuit in the Painless module is suppose to trip the relay to assist the start load. In normal running, the Painless circuit is supposed to let the main battery be charged up first, then allow the aux battery to get a charge next. Theoretically, the aux battery should always be there fully charged for assisting the main battery in the event it's needed to help start the engine. I may never find out if it works. I change batteries at 5 years as a matter of judgement to prevent being stranded on a hunting trip in the middle of timbuktu. That has worked well for me.
