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Sunday, January 26, 2020

There they are!

That's the new charge controller. It is heavy and big. I looked and it has three different ways of mounting it. On the back there are what look to be threaded screw holes so it can be mounted to brackets or something. There are also keyhole cutouts so it can be hung on something. There were also some small mounting brackets with threaded holes that allow me to mount it on a surface using my own screws. Measuring the holes allowed for screws, having mounted the brackets to the controller, it seemed they were 4.3 or 4.4mm in diameter. I suppose I could drill the hole bigger and use one of my 8-32 bolts. That would probably work best. I have a pile of 8-32 bolts somewhere and lock nuts too. 
Today being Sunday and a day when not much happens, I didn't do a lot. In fact aside from going to the store to pick up some food, nothing much did happen. There were the usual people dressed to the nines for church but that was about it. No knock-down drunken brawls or long walkup gunfights on Main Street. Even the meth heads were behaving themselves. In fact the most exciting thing to happen today was that a leaf fell off a tree.
This is the old charge controller. This was allegedly USA made which is why it cost me $30 rather than the usual $10 for a Chinese charge controller. Oh, I have a long history of Chinese charge controllers. They usually end up blowing themselves up after a few months.

I've been through several of the blue ones with the digital display and several of the black ones with LEDs. I've had them rated at 10A, 20A and 30A but curiously the connectors are not capable of taking wire of greater than 14 gauge. Even more interestingly, none has survived beyond about a 6amp load. They're probably good for charge controlling but not good at all for discharge controlling.

Notice that the battery says 65%. The batteries have been charging now for the whole day since there's nothing but sunshine. I even have the little fake 60watt panel that produces 10watts standing in the sunshine. Two 35AH batteries with virtually no load should charge rapidly. In fact, earlier in the day they were reading something like 86%. Now despite constant charging they read just 65%.

Looking at the space where the charge controller is located, I do have sufficient space to install the new controller though I'm going to have to go into the panel behind and dig out the spray foam I put in there a while back. That stuff is the worst nightmare for bus constructors! It promises so much yet yields so little and causes so many problems. Once that's done I'll be able to get in and bolt the new controller to the panel.

I'm really not sure whether it's the charge controller that's at fault or the batteries at this point. If I were a betting person I really wouldn't know which way to go. Having got the controller, the next step in logical sequence is to install it. This one comes with a temperature probe that's supposed to be sited near the batteries. That's no problem. Just siting it underneath the bus is good enough.

I looked up the cost of replacing the AGM batteries with LiFeP04 batteries and the price was outrageous. For 100AH they wanted $1,500. Even a 30AH was $250. For the same money I can get three Duracell 35AH AGM batteries. Even crazier, neither has much of a life span. 2-3 years max.

It looks like I have quite a few projects on the go. I'll have to get them done one at a time. I'll have to concentrate on finishing things rather than starting new ones:
1. Replace the roof vent.
2. Redo the panel on the bottom of the back door.
3. install the new charge controller.
4. Install the relay and solar power line so I can power the front and rear cameras when the bus isn't running.
5. Install the new solar array at the front, replacing the compromised plastic solar panel.
6. Continue to close up the other windows on the back of the bus.
7. Install security mesh over the side windows, each side.
8. Install new tyres.

Having done all that I should be free to use it for a summer jaunt.

While I was rooting through one of the boxes of screws and what not, I noticed my hands smelling of pee. Then I remembered a rat had been in the house where the box of screws and what not were stored. In fact, not just a rat as it turned out but a whole colony of rats. Everybody moved out of that house just in time! If I suspect a rat in my bus then I will have no hesitation in driving it to a remote location and fumigating it with hydrogen cyanide gas. It's relatively easy to make and will be my final solution to the rat problem. My extraction fans will clear the air relatively quickly.

So, at about 4:45 I disconnected the solar power and the battery from the charge controller. Nothing - absolutely nothing can be discharging the batteries now. When I did that, the controller was reading 56% or in reality 56% of the 50% I should regard as maximum discharge of a battery. In other words, 78% of where it should be.

Roughly an hour later, at 5:40 I reconnected the battery and the solar panels. The battery was reading 52% of capacity available. Interestingly, all three independent volt meters wired into the system read 12.7v. The solar power coming it was around 10.7v by then or basically no contribution with a PWM controller.

Interestingly, 52% of 50% is 26% and that would make for a 76% full battery. According to a table of values I found, a 75% full battery should read 12.6v and a total of three volt meters told me the battery voltage was 12.7v. A few minutes later after using some lighting to find something and setting the security camera going, the metered voltage had indeed on one meter dropped to 12.6 but another read 12.7 so it must have been close.

Though I'd like to point my grubby little index finger at the charge controller (because I have a new one and because it was cheaper than new batteries), I have to accept that it probably really is the batteries that are on their way out. Word has it that even deep cycle batteries just don't last too long. I think the Harbor Freight one could have been a little abused anyway. I'll have to add a battery tester to my next Harbor Freight trip. Now that won't be this month but could figure into a trip next month. I had an unplanned expense this month so I had to mortgage the pussy to pay for it.

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