This thing was in unedited and unfinished form and got sent by dwarves while I was sleeping. Damn dwarves.
So I'm cleaning it up just now and re-sending. Please ignore the earlier posting. Dwarves did it. One of Mark's pictures had a lithium battery in it and since batteries have been on my mind lately I thought I would recount my experiences lately. I left off with the previous email the dwarves got ahold of saying something about Ken Cottle having built my battery box on 335KC to hold a garden tractor battery. The reason for the bigger battery was because when he built the plane the starters that were available were not geared. They were direct drive and needed a lot of amps - that's what he told me about his reasons for using a larger battery. Motorcycle-sized batteries were the norm back then just as they are now for KR's. As for why he mounted it on the hat shelf, it wasn't for CG reasons as I suspected but rather simply because there was no room for such a large battery on the firewall. Having the larger-than-normal sized battery box has been a huge advantage once I started adding electrical loads to the plane. With the Diehl alternator/generator (I've been calling it an alternator but somebody just told me it's a generator because it uses magnets) not turning very fast, the battery has to carry the load of all the things that are on at night when coming in for landing with power at idle. The secondary ignition is 8 amps just by itself, at idle. The two landing/taxi lights are 50 watts each, the position lights draw a bunch of amps, plus transponder, strobes, radio & linear amplifier, beacon, all the panel stuff like GPS, instrument lights, fuel flow meter, etc. I calculated the load a long time ago and have it all noted in the logs but things have changed so need to do that again, especially now that I'm putting a new battery in. It's time for a fresh evaluation of my primary electrical system. I do have a secondary, back-up electrical system which (I thought) was completely separate from my primary system. I designed it that way but somehow I've accidentally got them linked since the last time I turned the secondary system on it engaged the solenoid on my primary system. Somehow along the way, over the years, I've connected something that compromised the isolation of each system so that whole thing needs to be re-thought and re-done and perhaps done away with entirely. The secondary system has it's own 20+ Ah battery that was intended just to drive a fuel pump and the artificial horizon. Since I put that system in I have learned that the engine will run just fine with the Ellison on top without any fuel pressure beyond siphon pressure. Fuel level in the header tank is below the level of the Ellison yet the engine will continue to run with the fuel pumps turned off . . . so darned if I know why it does. I didn't think it would, which is why I put in the secondary system. As for driving the horizon, there are better solutions available now than back when I put this electrical system together. That little Dynon D2 for instance. You can just about replace the whole panel with one of those and it'll run on its own built-in lithium-ion battery. Back when I was looking for the best battery I could find with the dimensions of a garden tractor battery, I found only one that was exceptional. It was the battery for the Mazda Miata 1991-2005. It was AGM, 32 Ah with 400 CCA at 32?. I think it was 2007 that I found that battery at Powerstride, a company that has a location here in San Diego. I paid about $185. The Miatas came from Japan with Panasonic AGM's installed but those batteries are unavailable here in the U.S. so dealers have been recommending one made by East Penn with pretty much the same specs as the one I've mentioned above from Powerstride. Since I bought mine, other suppliers like East Penn have brought their products to market so prices have dropped and variety has increased. This "Miata Battery" (which is how it is known and referred to in the battery world) now comes in both AGM and flooded cell designs. Length and width are standard for this battery but height varies in some cases. The battery I bought in 2007 has been slowly failing over the last year or two causing many and varied electrical gremlins. It always took a full charge and kept it so I haven't realized (until my trip to MMV and another trip to Big Bear immediately following) my electrical problems have been due to the battery. I've been chasing grounds and and looking for other possible sources of problems. I almost sent my TruTrak artificial horizon back to the shop since it was acting up intermittently but that would have been $400 wasted so I'm glad I didn't. When batteries start failing the results are all over the place. Very tricky. This will be the second time a failing battery has fooled me into thinking I had problems from sources other than the battery. The other instance was with a car. Since this Powerstride "Miata Battery" has served me so well my intention was to replace it with a duplicate and was at the point of doing that when I stumbled onto another battery Powerstride sells that has the same physical dimensions as the Miata. It's called an M44 and has amazing specs. And only nine dollars more. Links to both Powerstride's battery site and to some pictures I took of my new battery are below. This M44 is 3/4" higher than the Miata battery so I've had to so some cabling mods to get the wires to reach. They were at their limit with no slack so I've had to take some care in doing my extensions. But well worth the trouble. For nine dollars more I'm getting 55 Ah instead of 32 Ah. CCA at 32? is 570 (instead of 400) and reserve capacity is 59 minutes vs 45 for the Miata. I Googled J.I.S. and found out it stands for Japanese Industrial Standard, a quality control designation they use in Japan. I don't know why Powerstride carries this battery since it's not used on any vehicles in this country. I couldn't find any other sources for this battery except Powerstride. It's a pretty amazing battery considering it's got the same physical dimensions as an ordinary garden tractor size. In Japan this battery is used on three cars produced there - forgot which ones but they're not for export. It has "pencil terminals", but comes with lead shims that bring terminal diameter up to our U.S. standard. It also comes with a choice of positive on the left side or the right side as you face the battery. So it is designated as either M44L or M44R. It's important to know you have that choice in ordering. It weighs 28 lbs. wheras the Miata weighs 25. I'm curious what others are using to carry their electrical loads when flying at night and coming in for landing with power at idle. There's nothing in motorcycle sizes, lithium or not, that will carry a large load for more than a few minutes. The smart thing for me to do would be to replace my landing lights and position lights with LED's and reduce the stress. Finding LED landing/taxi lights would be easy but I don't think anyone makes LED bulbs for my existing position light fixtures. I need to look into it but meanwhile I do have a battery that will carry everything all by itself and do it with plenty of margin. Sure love that word when it comes to anything to do with flying. Margin. Margin. Margin. I need to do some calculations on just how long it can carry my full load of amperage but since the Miata 32 Ah battery would do it for a minimum of 20 minutes, this one will give me much longer. Link to Powerstride's M44 website: http://www.powerstridebattery.com/lawn-garden-batteries/m44-agm-j-i-s-bat tery Link to pictures of my new battery: http://1drv.ms/1P89PqH Mike KSEE ____________________________________________________________ Gravity + AOL ??? We???re just getting started Late last month, we celebrated one year since Gravity joined the AOL family, greatly accelerating AOL???s strategy to create more engaging, relevant and valuable experiences for its consumers, advertisers and publisher partners. http://thirdpartyoffers.juno.com/TGL3141/561b7a59d16b47a596d40st02vuc
