Day: February 15, 2013

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So… The New Solenoid

This is what Harold Barre has to say about using an engine alternator to charge an RV house battery on page 112 of Managing 12 Volts:

… If your house batteries are discharged to at least 50 percent of charge, the standard alternator charges your battery with about 15-20 amps until the batteries approach full charger. … You want to run the engine until the alternator output drops to about 7 or 8 amps; at this point it does not produce enough amperage to make running the engine worth while.

Keeping that in mind as well as the fact that my batteries are at about 98% right now, I am quite satisfied that as soon as I turned on the engine to Miranda tonight, voltage in the house leaped from 12.55V to 14.04V and I had 6.5A coming in. 🙂

It definitely wouldn’t be worth running the engine for two hours a day to get 12A in, but on a grey day it would be worth running the engine that long to get the 14.04V to print, charge the computers, or do whatever AC I can and want to do through my inverter.

We’ve got a grey spell ahead, so I just may let my batteries get a little lower than comfortable to see if I do get more amps when my batteries are further discharged.

It will also be interesting to see how much charge my batteries get while I am driving.

For the curious, I’ve got about 12.27V showing and I have on two LED lights, the fridge (on propane, which still needs a little DC since a modern one *g*), the whole house inverter, the UPS in the study, and three external drives. Total amps going out: 3.85. Hours till the battery is fully discharged: 35, meaning I could run like this for 21 hours.

Last but not least, I get a slightly less (and I do mean slightly) jaw dropping voltage drop when I charge the computer through the factory-installed outlet in the living room, so I will be using that one until I can hard wire in a new one in the study.

I really was ready to throw in the electrical towel, but the profound satisfaction I feel tonight makes the frustration worthwhile.

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A Little Paint and a New Solenoid

I can’t believe I was hesitant about painting the new wall yellow. It now feels like a proper room in here!!!

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I definitely need another two coats on everything.

Now, the solenoid project. As a refresher, the solenoid is what allows an RV house battery to be charged by the RV truck alternator when the RV engine is running. Mine has worked intermittently but recently failed completely.

L and his buddy B came over this afternoon and I knew immediately that my rig was in good hands because it was obvious that they knew what they were doing!

We started by testing if the solenoid would click when the key was turned to the on position. Nope. It was time to get a look at the dang thing.

Pulling the battery and getting to the solenoid required three sizes of socket wrenches. It also took two strong men to pull the battery out. Definitely not a job for me. I don’t even own socket wrenches!

Once they could get to the solenoid, they jiggled some wires, connected the battery via my heavy duty super long jumper cables, and had me turn the engine on. Click. But nothing was happening in the house.

They decided to pull the solenoid to clean the contacts. That done, we hooked it up to the battery and tested it. Click.

Next test was to check the voltage coming in from the house to make sure the problem was not at the battery bank end. 13.8V.

Next test was to check the resistance in the solenoid. Ooh… massive amounts of it. But the more we made the thing click, the less resistance there was and we finally got resistance down to almost 0. There was no way that thing was going back into my RV, not with how iffy it was and hard to get to.

So I was sent to town with the old one to find a new one. I went to O’Reilly’s auto parts and the guy at the counter knew exactly what I needed and they had one in stock. I almost fainted when he told me the cost was $50.14. The budget’s really tight this month but you got to do what you got to do. The cashier laughed when I handed him exact change. “Not fifty, fifTEEN.” As in it was a $15.40 part. WOW!!!!!!!!!!!!!!

This is my old solenoid:

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The new one is identical except it’s shinier.

I got it home and made L test it before B installed it. Everything looks good on the engine side, but nothing’s happening on the house side. We think it’s because the alternator recognizes that the house batteries are full.

I am going to use a lot of power tonight once the solar cuts out (my rig needs vacuuming…) and then try the engine. If I don’t see any results, then all three of us are at a loss, and two of us are engineers! But we are optimistic!

I had to two regular Buds in the fridge and one Bud light, so we had a cold one once the hood was closed. Retired friends make for cheap labour! 😀

Croft, I know you’re waiting with bated breath for news of this project, so I will report ASAP once I do the test tonight. We’ve still got about two hours of daylight left.

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License to Kilz

I awoke to bright blue skies, a gentle sea breeze, and no pressing projects ahead of me for a few days. It was time to start work on repainting the front room!!!

Unfortunately, I had a lot less Kilz left than I thought I did, barely enough for the new wall and one side of the pocket door. I am going to need more, which sucks since I’m going to end up with leftovers.

The primer dried almost immediately, so I was able to put the first coat of yellow on the new wall. I’ll do a second coat this afternoon, then let the two cure for a day or two. That will give me time to wash down the other walls with TSP and then I’ll do two more coats over the entire room.

My boos are not happy about being locked in the rear part of the rig, which has the best view, with only food, water, the litter box, and several soft lounging spots for comfort. Must be tough being a cat.

L came over a moment ago to ask me if I wanted to work on the solenoid this afternoon. YES! So this is going to be a day for projects.