Friday, November 21, 2008

Battery testing and a good inexpensive charger

I have been testing a good number of batteries lately that have been coming out of UPS units where I work. I had 2 dozen sitting in my area last week. I am down now to half of that, but I have quite a few at home still that I need to check out (and a large pile that needs to be taken to the recyclers too).

In order to do this, I needed to be able to charge the batteries up in order to run them down with my tester (a CBA II). I found a really nice charger for a really good price - a Tempest BC-1250. I ordered 2 of them and so far, I really like them. They are well built (metal cases, sturdy cords) and the voltages they use are just right for the SLA batteries I use. If you have batteries sitting around going dead, don't wait - this charger is worth the $32.50 - you need to charge them up periodically so they don't sulfate and kill themselves. If you charge them up separately first, one of these chargers should be able to maintain several small/medium batteries connected in parallel.

Since I go through at least 2 charge/discharge cycles on most batteries, it has been nice to have a couple of extra chargers (I can drain them a lot faster than I can charge them). They have been perfect for the relatively small batteries I've been working with (mostly 7 & 12 Ah, but a few 18's also). For larger ones, I still have my other bigger charger.

For something that can maintain (or very slowly charge) a battery at the proper voltage, get one (or several) of these Float Chargers from Harbor Freight.

Tuesday, November 18, 2008

Getting APRS running again

I'm going to try to get my digipeater running again. I swapped the dual port TNC I was using for a single port that has APRS capable firmware. I won't be running an I-gate anymore, but there seem to be enough around here already. I just want it to provide extra coverage for the area.

This site in Finland is doing some really cool things with APRS. It's best to use your callsign as your username, but make something up if you don't have one, or don't want to give it.

So, the first thing I've got to do is get a USB to serial adapter to connect to the computer so I can program the settings in the TNC. Once I set it up, it can be disconnected from the computer (a major source of problems in the past) and run on its own.

The radio is a Phoenix SX 16 channel and puts out somewhere around 30 watts. The antenna is an 8 foot Diamond X200 clone installed on my roof about 30 feet up. Power is supplied by a home built power supply that float charges a 75 AH battery.

Wednesday, July 09, 2008

MPG in my RAV4

This past weekend, we took a trip to Idaho. It was about 250 miles in each direction and for the whole trip, I was able to average right about 23 miles per gallon while doing 80 MPH on the freeway. We were late leaving, so I may have even been pressing the speed limit a little further at times on the way up there. We had 5 people (4 adults and a 14 year-old in the 3rd row seat) and a bit of gear. I had fully inflated the tires to their maximum pressure (not the pressure listed on the car's sticker) of 44 PSI. I left my roof rack on top because it supports my ham radio antenna. I did not use any fuel saving methods (like pulse & glide or drafting a truck) or anything other than the tire pressure. Since this is our first really long trip in the RAV4, I wanted to get a baseline for the future. The 23 MPG number isn't that great (the EPA estimates on this vehicle are 19 city & 26 highway), but it's not bad considering the speed and load.

I do have some history with a trip we used to make quite often. It is a 30 mile drive with about 5 on city streets and the rest a single stretch of 65 MPH 4 lane freeway where people usually drive about 75 MPH. We mostly made the drive with just my wife and I in the car. I would usually get about 25 MPG on the way up, and 22 MPG on the way back (uphill vs. downhill + prevailing winds make the difference).

The other day, after filling the tires full and using some pulse & glide, some 3-car-length drafting for 10 miles of the trip, and keeping the speed down to around 70 MPH, I was able to get 34.4 MPG on the way up. Keeping the speed to 70, but without any other methods gave me 25 MPG on the trip home that day. I'd like to play more with Pulse and Glide, but it requires that I pay a lot more attention to driving (I guess that's good) and not to my wife (that's definately bad :(

Anyway, I thought it was interesting that there is such a difference in fuel economy just by changing a couple small things (additional tire pressure, and a 5 MPH speed reduction) gave me 13% improvement.

I'm glad I have my ScanGauge to use because I'm hardly ever able to tell by looking at the whole tank of gas what I kind of economy I got for a particular style of driving. There are many times when someone will sit in a parking lot with the engine running to keep the air conditioner running. While I still check the overall mileage, it's always disappointing that it is so much lower than what we get on these 30+ mile trips that I like to test with.

Tuesday, June 17, 2008

Getting the most out of the gas you have to buy

I've read lot's of stuff about saving gas (Hypermiling, etc.), but this article is one of the best I read yet. It has common sense and gives sound reasons and advice for most of the suggested items. One part that lacked some details (like why it works) was the pulse and glide section, but since they referred to it as an advanced technique, I'll forgive them. You can find more info about pulse and glide all over the net. Here's an article from Consumer Reports with a new way of looking at fuel economy.

It has been a goal of mine for the past 15 years or so to own an electric vehicle. I haven't managed it yet (practicality and economy have had to come first), but the day is getting closer...

Sunday, June 15, 2008

Update to Move/Copy Tool

I've posted an update to the multithreaded Move/Copy Tool (McTool). Not a huge deal, but some needed updates and minor enhancements were made.

Check my original post or my web page for the download link.