The boobytrapped meter?

Today my new multimeter arrived today. It looks good and seems to work. The message on the back is a little puzzling though.

"Wear ANSI approved safety goggles when changing battery". How puzzling! Does this mean that my meter has been boobytrapped by the Chinese sounding seller in Texas? Is it all part of some inscrutable Chinese plot to take over the world? Is the infamous Dr No involved?

Perhaps I should refer this to the NSA as being a suspect package? Maybe it's a former lover getting her revenge in a sneaky manner? Maybe it's the husband of a former partner, finding that he has quite something to live up to.

Now that I've seen such a dire warning, I just had to open the back to see just what diabolical mechanism was lying inside. Retreating to an open space at the back of the four acre lot, I pulled out a screwdriver. The good ladies of the trailer were warned to check for nuclear fallout should the resultant explosion decimate a substantial area of the potato patch.

I must admit to being bloody disappointed! After opening the back there was no explosion, no shrapnel, no flying springs nor sailing banshees. There weren't even flying pixies rushing out of the case. It was boringly mundane!

Perhaps the oddest thing was the name of the battery!

Power solutions

Today I saw the perfect solution to my power problem. Lithium ion batteries look perfect. Looking at microwave usage at 1000W power consumption plus 10% loss from the inverter I'm looking at needing 1100W. Dividing 1100W by 12 volts gives 91.7 amps.

There is a very nice battery available that weighs just 28lbs. The size is right. It'll give me 100A output which is excellent for a microwave. How much heat is lost and how long it'll run at 100W without temperature shutdown is unknown.

Being a dream battery, its also a fantasy price. $1300 does look ridiculous. On the other hand, if it fulfilled all of its promise then it might be worthwhile. To get 100AH one would need two lead acid 100AH batteries. To get 100A from lead acid batteries I'm not sure how many would be needed. My best guess is about 5. That would be around $500 plus the weight penalty. Each battery would be 55lbs for a total of 275lbs.

Clearly going down the lead acid battery route is a bit like using an abacus instead of a calculator. Knowing this better technology is available confirms my existing plans to use minimal 12v battery power.

I'm pretty sure that I'll use solar panels to power a dehumidifier directly and to power a ventilation fan directly. At night that isn't so important as its cooler and generally lower humidity.

I definitely need to charge some battery that can recharge my phone though. Perhaps a simple 6v lead acid battery. I'll have to give that some thought.

Walmart had a sale

In that sale there was a roll of foam bedroll for $8. Very useful stuff! I bought a roll and will use it to make a honeycomb to put in my drawers in order to protect my crockery. I prefer real crockery as its easier to get clean than plastic crockery - particularly when its handwashed!

Meanwhile, a tragedy struck a couple of days ago. My old Sonicare toothbrush died. The batteries in them degrade over time until they finally just won't hold a charge. As they're sealed unit batteries, nothing can be done. It's quite frustrating and I really didn't feel like spending $100 on a brand new unit. I liked the small head and the way it really worked.

The problem with the old unit was that the charger ran solely from mains voltage. That would have meant a big battery and an inverter in the bus. I'm not a fan of inverters as they waste power.

Bravo! It seems there's a Sonicare battery operated tooithbrush for $10. I got one. I'd been wondering how I was going to work around my toothbrush needing mains power. It takes two AA rechargeable batteries. Now those can be charged from solar power!

By now you'll have noticed two things. The first is that the sink unit isn't very clean. The second is the water dispenser. Underneath the sink is a bucket - just like the one destined for the bus. Yes, I do live in a low rent place!

Since batteries are expensive, the plan is to make a compartment that will carry two batteries. I might put a single battery just so that I can charge my phone etc overnight. As much as possible will be manual. This will be a low power consumption motorhome.

Progress this week was minimal

I'm waiting for things to arrive which is frustrating. I'm also waiting for my next paycheck before I buy anything extra. I cannot go over what I earn without reducing myself to such a low level that life would be intolerable.

Today got off to a slow start but I replaced the countertop on the bathroom vanity. It just seems more sense to have a countertop and a plastic bowl when I need to use water. The bowl can be tossed into the shower when its not in use.

Aside from trimming that top to shape (its not rectangular), I looked around and found a cigarette lighter plug. That can go into the cigarette lighter socket in the console with the other end connected to my solar panel. In theory that should put some charge into my bus batteries. With luck, more than is lost.

I looked at the welder instruction sheets and found a very useful information sheet on how to weld. It doesn't mention hitting the cooled welds with a hammer to check for failure but it looks very useful.

On the other side is a setup instruction sheet. That looks equally useful. I gather the handheld face mask probably isn't that convenient but unless I really need to use both hands, I'll use it. From a safety point of view, one hand employed holding the mask seems better.

I believe I mentioned yesterday reading the instructions for the welding rods. As can be seen below, they are very informative and useful. I wouldn't mind betting that people writing negative reviews of the Harbor Freight 70A welder haven't bought the right rods or used the right power supply.

Meanwhile, I'm definitely finding the cooler weather makes for a chilly experience, working outside. I must be getting soft in my old age!

An interesting day!

The primary goal of heading out today was to get my car serviced, which happened this week. Now I don't have to worry about it all. Sure, they were on about rotating tyres and the age of my battery and radiator flushes. My tyres rotate quite well as I drive down the road and anything else gets done when needed. In other words, the battery gets replaced when it stops starting right away.

Speaking of batteries, two of my purchases arrived today. The first was a 5A solar panel and the second was my enamelled copper wire. I'd have got on with making electro magnets had I not completely forgotten to purchase appropriate bolts.

With this wire, I should be able to make far better electro magnets than the Chinese supplied and make sure they work with my setup! I could have saved a lot of time by doing this from the start.

The solar panel is 12v, 5A and is intended for use as a battery keeper. A quick test using a 12v panel lamp proved the panel works well even out of direct light. Note that the panel is sitting on a shaded step on the bus with the lamp connected. The plan is to put a cigarette lighter socket plug on it, put the panel on the dashboard where sun will shine on it and to plug it into the electrical system. That should slowly trickle charge the battery and ensure it doesn't go flat.

Another thing I got was a 70A welder. Looking at the reviews, it seems most of the complaints come from people that can't read. Looking on the sides of the welding rod boxes, amp ranges are specified. A rod for 25-45A will work well as long as the power is turned down. A rod for 45-90A will work well. A rod for 90-135A will not work. I was pretty careful to read what it said on the boxes!

Now the next issue is the welder needs a 20A power supply. That doesn't exist right now. It will have to be installed on a separate pole outside. Fortunately I have a suitable box. The first task though was to hack my way through a jungle to get to the box.

Having reached the pole, I investigated the box. It's going to be "interesting" wiring it up with a potential 200A running through it all. Fortunately there are spaces where breakers have been removed and there's a hole in the bottom of the box. There's plenty conduit taken from the hillbilly installation that can be used.

As the conduit is a bit of a funky shape, there will need to be a separate pole for the new outlet. Clearly I'd have to buy more electric cable. It's all doable though it might be next weekend before I get started. Right now I have several projects all needing extra parts or preparation work. It's a little frustrating!

To add to the frustration, my multimeter has indeed died. It seems the needle is sticking. I have no idea why as it has been stored dry, never abused and not used a great deal! It worked a few months ago. Clearly I need to replace it as its now unreliable even if I did get it to work again.

It's probably had a reasonable innings since I bought it about a decade ago. I remember buying an inexpensive meter. EBay came up trumps. $4.99 got me a replacement with a digital display, shipped from Texas. I'm not in a great hurry for it so I can afford to wait a week. There's plenty else I can do without a meter.

My latest plan is to continue on with eliminating the handbasin in the bathroom, turning the vanity top into a straight countertop. That makes far more sense to me. I can use the counter for a gas cooker or for a plastic bowl to do my washing etc.

The Power Budget

The reason I'm putting in a 120V plugin is because solar and battery power are so horribly expensive. The reason I'm going with a bucket and Jerry can approach to water is based on cost also.

In my eagerness to proceed, I've forgotten my underlying principle of low cost. I've also allowed myself to be trapped by the hillbillies into following their ideas and plans. The electrical box the hillbillies put in was ludicrously large for just a cable compartment! It looks kinda sensible to use it for batteries.

The microwave would use 1200w at 120v. That's 10 amps! Without even considering the losses from using an inverter, running the microwave for 15 minutes would burn up a lot of power. Converting 1200w at 120v to 12v would be 100 amps. Given that a full battery holds just 105 amps, discharging it in 15 minutes would probably melt it!

While it would be possible to provide 100A at 12v, it could take quite a few batteries. Certainly more than the planned two! Thus, where the battery compartment is planned probably isn't the best location.

The big door put in by the hillbillies is a huge red herring, in my opinion. Far better to rivet the hillbilly battery door closed, make a smaller compartment and door for the 120v supply.

As far as electricity generation, solar panels seem quite pricey. As the roof is curved, flexible panels make the most sense. At $200 for a 100w panel, solar isn't cheap!

In terms of other power usage, I'd be charging my phone, batteries for my lanterns etc. No heavy usage save for possibly a fridge. If it was a Peltier fridge then the usage would be 5AH or 60W.

Although I don't like gas, it looks like being the sole solution for cooking unless the bus is plugged into a power supply. Refrigeration, small battery charging, ventilation etc could all be run straight off solar with a cool block in the fridge to maintain coolness at night. Perhaps a small 6v battery to maintain cellphone charging capability at night.

Looking up NiMH cells, it looks that once one goes beyond AA and AAA cells, prices rocket. That is rather frustrating!

Looking in another direction, generators have a place. A well installed 1800W generator could charge a single battery while providing power for a microwave. The trick there is to set the generator for remote start and remote stop.

Whichever electrical solution there is, looks like being several hundred dollars. The cheapest is gas and no electricity. There is, of course, no reason at all why gas couldn't be the initial solution then electricity later.

Meanwhile, I'm reconsidering welding. It might be fun to have a go at some welding.

More thoughts

The cheapest way forward would be to use a small camping gas stove and a small gas cylinder. Thinking about where to put the stove, the easiest place would probably be the bathroom countertop. Its also the safest as there will be no flammible curtains in the bathroom. Instead, squares of shower curtain will hang over the windows, attached by Velcro.

Do I really need to have a 12v electricity supply? Can I get by with just solar panels leading to USB charger sockets? That would keep my phone and tablet charged during the day. Maybe even my D and AA cells too.

I think my big question is whether I really need 24x7 electricity. There's no way batteries can produce sufficient power to run any form of cooker. No cooker I've ever encountered uses less than 1,200 watts. The lowest power consumption fridge uses 138 watts which seems quite high compared to a 60W Peltier cooler. Indeed, using all 12v equipment means I can eliminate the need for an inverter and its associated power loss and cost. It just makes life simpler.

60w at 12v is 5A. 24 hours at 5A is 120AH. Given that solar panels should produce power for at least 6 hours, the amount used should not exceed 18 hours or 90ah. That means the battery should be at least 180AH.

Looking at batteries, lead acid batteries are available but they're about $300. Lithium batteries are around $1200. That's pretty disappointing! To be brutally honest, the thought of hanging 200lbs under my bus makes me nervous, particularly when its in front of the rear wheels. That's where lithium batteries sound good as they're lighter.

Having looked around, the best seems to be to get a pair of 105ah 12v deep cycle batteries at $85 each. They're 55lbs each.

This is, of course, the time I'd really like advice but there's just nobody to ask. At one point I was on Facebook and there was a group that claimed to be building their own bus conversions but when it got to anything remotely technical, they didn't seem to have any ideas. Similarly on forums, nobody had a clue when it got remotely technical. I rather suspect few were really doing their own bus conversions. The really interesting thing was that the one person who was at the point where he was going to register his bus as a motorhome never reported back as to his success or failure.

Onward and upward. I'm hoping to have the conversion completed by January. Only a year behind schedule!