Archive for the ‘Electrical’ Category

Solar Trickle Charger

Monday, July 4th, 2011

The bus has been parked for a year and a half due to a brake caliper seizing. For much of that time, the keys have been at Neighbor Dan’s shop and he’s been waiting to fit it into his repair schedule. That’s a topic for another day; but for now, let’s talk battery charging.

Car batteries left alone and unused tend to self-discharge, but the bus’s starting battery seems to discharge a little faster than I can account for just from disuse. I’ve kept my van battery topped off with a $15 solar trickle charger from Harbor Freight, and I recently modified one to use in the bus.

Bus battery with trickle charger wiring

The bus’s battery compartment is below and behind the driver and is accessible through a door in the bus’s apron. In the long term, I’ll be routing much heavier DC wiring throughout the interior; but for charging, I ran a 4′ section of 18-gauge two-conductor cable out the back of the battery compartment and up through a hole the previous owner had made in the floor.

I put a 1A fuse inline with the positive terminal connection, as the 120mA solar charger should never come near that much current and I would prefer the 18-gauge wire not become a fuse during a short-circuit. I can easily change the 1A fuse out for a larger one later.

Anderson Power Pole wiring in schoolbus RV conversion

The cable emerges from the floor behind the driver’s seat, where I terminated it in Anderson Power Poles. The battery is deeply discharged — less than 3V. This battery may not resuscitate, but at least the charger will be there and ready for the next one.

Solar trickle charger on bus dashboard

During the afternoon the dashboard was in shade, but the charger still read about 17V open-circuit. With it plugged in, I immediately measured over 5V at the battery. Although it obviously hasn’t charged the battery that much that fast, it’s a good sign.


Date Voltage
04-Jul (pm) 2.79
04-Jul 18:34 5.43
05-Jul 17:57 8.00
06-Jul 19:23 6.90 *
10-Jul 17:06 9.01
11-Jul 18:01 9.12

* The positive terminal cable clamp had been cracked and broke off from flexing on 06-Jul. Replaced 09-Jul.

Serious Paint Removal Attempt #1: Too Fast!

Saturday, June 13th, 2009

Stripping paint down to bare metal

I got a 4″ disc wire brush for my angle grinder, thinking it would strip paint a lot faster than the cordless drill. It did — it stripped down to bare metal when I barely touched it to the bus!

I suspect the original primer is a lot better than anything I can buy, and certainly better applied, so I really don’t want to remove it; I want to leave the primer and maybe even yellow paint to cover with my own paint job.

If I did want to strip to bare metal, the brush I was using in the angle grinder would be great. For this job, I’ll see if I can find a finer brush for the grinder.

Also I need to find one with a 5/8″ arbor. Drilling a 1/2″ arbor out to 5/8″ causes separation of the metal plates formerly holding the wire pieces together. Careful application of the angle grinder’s arbor plates gets the wires held pretty securely — and remarkably concentric on the first try — but that’s no way to really do it.

Bus with a few linear feet of purple paint stripped

I switched to the “wire brush on a stick” in my corded drill and got a few linear feet of above-the-rail stripped. Took over an hour and it really wasn’t worth the effort.

Battery Compartment and AC Wiring

Bus battery compartment and AC wiring

I hadn’t leaned down far enough to really look in, so Jonathan was the original discoverer of the AC wiring sticking into the battery compartment. I’m guessing the former owner had an inverter installed in there — which I just read is a bad idea, as the battery acid fumes can eat up the delicate inverter guts. Maybe I’ll put mine in a separate compartment.

But What Will the Neighbors Think?

My neighbors saw the bus this afternoon for the first time. The folks next door think it’s really cool and a great idea. The man of the house from two doors down came over to say that “The Landing Strip” (painted on the front of the bus) is a bar in Aggieville (Manhattan), which gives a clue as to the provenance and likely former owner of the bus.

The best reaction was from the young couple across the street. As they were halfway across, they were already calling out that their curiosity had got the better of them; and they gushed about how cool the bus is and asked all kinds of questions. They let their four young kids explore the inside of the bus, and didn’t mind at all that they were enthralled by the dead baby mice. They’re all very enthusiastic about the project and the prospects and think it’s great!

This was, of course, before I backed into their mailbox, as one of the part-time police officers I don’t know came driving down the street.