The batteries that weren't

Today was supposed to be the day that I sealed all the remaining rivet holes in the front of the bus. That's not quite what happened though. While I did cut a piece of aluminium with the idea of gluing one piece with a hole drilled in it, ready for a rivet to the inside of the area where I'd made the big hole for the wire from my old solar panel, I didn't get that far. The idea there was to glue the metal on the inside then after the glue had set to fill the space with Bondo and rivet another piece of aluminium to the other but from the outside so that it went aluminium, steel with a bondo filling, aluminium. 

Meanwhile a sign arrived that I'd bought online that said "State Pennitentiary". Yes. I put a spelling mistake in so I can't use that at the front over the windscreen. I'd hoped it would come with relief lettering too as it said on the website but it all came flat. That was pretty damned useless. It didn't cost the earth, thank goodness and I'm sure I can use it elsewhere even if only for the metal.

As I went to the bus I noticed the batteries I'd charged a few days ago. They claimed to be 16.18v or about 4.2v each which sounds about right for a fully charged 18650. Thus it was time to test their capacity. Their claim to be 5,600mah was completely unbelievable. Only a fool would believe that capacity, to be honest.

The test setup was very simple. The batteries should not be discharged below 2.75v each so I put a cheap and nasty Chinese charge controller on the battery and a 3 watt LED light as the load. To monitor everything I put my watt meter between the battery and the charge controller. If I'd put it after the charge controller, when the controller switched off, I'd have lost all my records. 

So at 1:30pm I set the whole lot going on the deck outside and waited. It was a pretty hot day but what with having to chase a neighbor's wandering cows away from my veggies, fairly uneventful. 

After about 90 minutes the LED bulb had done what LED bulbs do best - it had begun to fail. The one LED remained lit but the other two flashed on and off. Power consumption went up and down. That 3W LED used 9.7W, which was surprising. It was a new LED bulb in that it had never been used before. I'd bought a pack of 3 and tried one, finding it got surprisingly hot. That was why I had not used it before.

With the broken LED extending discharge time, the LED was replaced with a 10W halogen bulb which used 17.8W. That worked really well. Fairly soon thereafter the battery power level reached the 11v switch off stage and I could check the power usage.

Looking, it seems the 4 batteries (in series) came to 1.173Ah or 1,173mAh. That's quite a way off the claimed 5,600 mah. It's not even quarter of the claimed capacity. Clearly they're not going to be much good as part of a replacement for the twin 35ah lead-acid batteries on the bus. On the other hand they're pretty good for my drone project being both lightweight and having a decentish capacity.

I keep running into the LEDS are worthless problem. Like a smoker addicted to cigarettes or a serial killer obsessed with killing their next victim, I keep on buying the perishing things. The thinking process goes something like... LED light has failed, scratch armpit. Must buy new LED light. Instead I should be going more along the lines of... The LED has failed. LEDs keep failing. This is a dismally ineffective technology that costs a lot of money. Instead of spending $8 on packs of two or three LEDs, why not spend $5 on a pack of 10, ten watt halogen bulbs.

Well, I'm half way there. I have the ten 10 watt halogen bulbs that I bought for $5. What I need to do now is to rebuild my light fixtures to allow more space between them and the walls so I can actually use halogen bulbs throughout. I might also put some reflectors around the halogens.

It does not matter what LEDs I try, they all seem dismal failures. I have seen the LED lights on the work busses fail pretty regularly. It doesn't seem to matter what kind of LED is in use - they all seem to fail. I like the two pin mounts I chose for my lighting though. It's so easy just to put a two pin bulb in place.

In terms of power consumption, 18W isn't that terrible. Using two bulbs at 36W I would get 10 hours non stop light from my battery pack before needing to recharge the batteries. Who uses two lights for that long though? I tend to use a single light most of the time because I have lights in all the places I sit and switch them off when I leave the area.

Well, tomorrow I might get on and finish up the holes left after removing the vandalized solar panel. After that I need to get on with replacing the rusty roof vent.