Sharkey's blog

Now that I've gotten the EV Rabbit back on the road, I have some charging issues to address. The on-board charger on the car is a K&W BC-20, which is small, light, and powered by a normal 15 ampere 120 volt wall receptacle. While this is convenient for opportunity charging, and works fine when I am at home and have a lot of time to charge, the current output of the K&W leaves something to be desired when filling up the batteries fast is required. The K&W is rated at 20 amperes, but it will only do this from a solid 20 or 30 ampere circuit, then then only for a few minutes until it heats up and cuts back power to keep from cooking itself. Most of the time, I see 17 amps of line current, meaning about 14-15 amps into the batteries. I usually have to cut back on the power when charging from 15 and 20 ampere outlets to keep from overheating the cord and plug ends. Even the higher power outlet that I tacked into the radio station's sub panel restricted the charging current to about 10 amperes into the battery, meaning that I had to wait around for three hours to fill the batteries before heading home.

What with $5.00 a gallon diesel, I've been working towards getting my electric car back on the road so that I can save some moolah on my weekly trip to town.

Last time I took the EV into town, which was shortly after I moved here, I barely made it the 15 miles to the radio station where I work. The car was crawling by the time I made it to town. I then had to wait six hours while the car charged up from an exterior electrical outlet on the side of the studio building because I didn't want to turn up the charge current and risk blowing a circuit breaker that might be feeding something else important inside the building ("Aaaargh!, We're off the air!!!!")

Well, so after crowing about how safe my charging regime is, I just had my first mishap.

When I went into the garage about 30 milutes ago to check the progress, I found that the Mil-Spac cell (this one is a Gulton brand) was disgorging small amounts of electrolyte out it's vent cap. I had been watching the liquid level in the cell with some concern, as it seemed like the cell was getting overly full, as if it had been manufacturing it's own electrolyte. Had I known this was going to happen, I wouldn't have added some distilled water before beginning the charging process.

Anyhow, I dumped the small amount of KoH off the top of the cell into the bottom of a cut-off water bottle, hosed the top of the cell off with the garden hose, then gave it a swabbing with a rag soaked in vinegar to neutrilise any remaing base. I then use an eye dropper to remove some of the excess electrolyte, and put the call back on charge.

This might be normal. I read a series of posts on the Electric Vehicle Discussion List a few weeks back about someone who had acquired some Nickel-Iron batteries that were completely dry. The were sealed batteries, and the user was wondering what to do about this before charging. He ended up just putting the dry batteries on the charger, and as if my magic, liquid appeared in the cell, eventually filling it to capacity!

The next one of these cells I charge, I'm going to leave it alone after cleaning it and let it make it's own electrolyte.

I do wonder about one thing, though. NiCd cells are supposed to have a layer of mineral oil floating on top of the electrolyte to prevent contact with the air. Seems that atmospheric carbon dioxide can contaminate the electrolyte, and carbonate it to the point were it no longer works properly in the cell. None of these batteries I'm fooling with seem to have any oil at the top? More mystery...

I'm charging the cells individually instead of in a bank as a battery. It will take ten times a long, but be at least ten times safer. I can also better control the voltage on a single cell, and make sure that it remains within the manufacturers recommended guidelines. Charging a battery of multiple cells results in much greater swings in voltage and current as the cells begin to accept a charge.

Yesterday, I checked the AC voltage going into the chargers, and it's around 17 volts, so the chargers are loafing on this job, no heat to speak of. When I charged the original set of 20 UHP65's I used this technique, and didn't see any unusual behaviour. Yet another caution is that I put the new cells on to charge in the early morning, and watch them for the next 12 - 15 hours, adjusting the current as needed. By bedtime, I have a pretty good idea whether the charging is stabilised and if it's safe to leave it to go overnight unsupervised.

There's now three chargers and variacs, with the Mil-Spec batteries now on line and getting the treatment. Got to do something useful with all the excess solar electricity. Yesterday, my dump load (the electric water heater) came up to 150 degrees F, and the thermostat switched it off. That meant that any excess production was entering the utility grid and I was being charged for the privledge of sending power to my neighbor's homes. After finding this problem, I cobbled up a three-way thermostat so that when the tank is up to temp, the excess power is burned off in an electric space heater, but that's a waste in the middle of summer.

Today, the Academy of Battery Rejuvenation graduated it's first cell:

The cell on the left is sitting at 1.617 volts after being charged at 2.6 amperes for 48 hours. The cell on the left is 24 hours into it's initial charge.

Today's big news is that I had to go to the city for some business, and took along some Trojan T-105 deep cycle batteries to have the "combination" screw terminals cut off and "automotive" round posts cast in their place.

When I dropped off the batteries at the warehouse, I noticed a stack of Alcad brand Nickel-Cadmium batteries by the roll up door. I asked the guy who was working there what the story was with them and he told me that their employees are idiots. Apparently, when new batteries are delivered, they are supposed to pick up any old cells that they see, and these had been collected some time in the past. I asked him what they were going to do with them, and he indicated that they were "just old, dead batteries", and that they were a problem for them, because of the toxic pollution potential of the cells. The business didn't have any way to get rid of the batteries, so they had just left them to sit by the door.

Got the whole story today of Roger's visit with Eric last weekend, scanned some of the photos. Apparently, one of the rolls of film he took didn't come out (too dark), so we don't have as much to choose from.

Here's some of the images that did come out:

OK, so yesterday (Sunday), Roger went over to Sisters, Oregon to meet up with Eric and take the tour of the new/old Federal housetruck. Eric was down from Washington state to attend a function in Sisters, and since the Federal is his "RV", he had it along.

I haven't heard from Roger, but he took along his (antique, film) camera and was going to take a lot of photos. Of course, we'll all have to wait until the film is developed and the prints (or negatives) are scanned before we get to see them.

Lately, I've been putting some finishing touches on the solar power system. In spite of having many more important things I should be getting done, yesterday I spent pretty much the whole day building an upgrade to the kilowatt hour meter that monitors the alternating current output of my system.

The meter that has been installed in the system since the beginning is a standard utility-type kilowatt hours meter, the type with the rotating disc and little numeric dials with counter-rotating pointers to indicate the consumption (or production, in my case). The convention in reading these meter is that you ignore any readings in between the whole numbers, rounding down to the next whole number. Obviously, my system doesn't produce electricity in whole kilowatt units, I wanted a way to track production totals more accurately.

Progress on the WORT2 has been continuing apace, and I've been enjoying doing some guessing about how the new living space will look Rob has now posted a page of plans that shows the basic layout and floor plan:

http://www.robgray.com/graynomad/wothahellizat/wot2/plans/index.php

This takes away some of my fun at guessing what is where, but also make it much easier to understand how the new rig relates to the old.

Rob tells me that he is using galvanized steel for all of the framing, and that none of the old body's materials will be reused, excepting the applinaces, fixtures, etc. He would probably sell off the old structure cheap, if anyone is interested! Anyone want to build a motorhome?