steingar Posted February 27, 2016 Report Share Posted February 27, 2016 So getting my Mooney M20C started in cold Wx is a royal pain in the six. I have engine preheating nixed for the moment, but am still struggling with the battery. If I keep it on a tender it works fine, but putting the battery box together is very difficult for me. If I leave it without a tender for even a week I haven't the power to get started. I'd leave part of a tender hanging out the battery box, but I doubt there's enough room to get anything out of there. I used to have the exact same problem with my Cherokee, but the battery was under the back seat. The voltage drop was pretty big. That said leaving part of a tender hanging out was no big deal. The battery in the Mooney is in the engine bay, not a good place for anything to hang out. Is this normal? It was for Cherokees, what about vintage Mooneys? Is my battery kaput? Is there a trick to putting the battery box back together? Quote Link to comment Share on other sites More sharing options...
StinkBug Posted February 27, 2016 Report Share Posted February 27, 2016 My C has a battery tender lead with the little rubber 2 pin plug routed through a grommet in the side of the battery box and zip tied to a hose or wire or something right next to the little door in the cowl. I don't ever use it because I'm on a tie down in sunny so cal, but if I did it would just be a matter of popping the door open and plugging in. Quote Link to comment Share on other sites More sharing options...
takair Posted February 27, 2016 Report Share Posted February 27, 2016 If it won't last a week, you likely have a bad battery. What kind of battery and how old? Your mechanic can route some wires for the tender as Dallas describes. Just be sure it is fused... Quote Link to comment Share on other sites More sharing options...
Guest Posted February 27, 2016 Report Share Posted February 27, 2016 Your battery sounds like it's due for replacement. As for the battery tender, why not connect it to the "hot" side of the master relay with an inline fuse. Clarence Quote Link to comment Share on other sites More sharing options...
Hank Posted February 28, 2016 Report Share Posted February 28, 2016 (edited) I used live in the pointy part of Ohio, 45 Mooney minutes south of TZR. Winter starts were difficult to do unless I plugged in the engine heat for about an hour, or parked in a warm hangar. Had nothing to do with the battery and everything to do with firing. That was before I OHed the carb and the SoS. The colder the weather the more I had to pump the throttle, too. Be sure to give the cold fuel time to vaporize: pump throttle vigorously at least 5 times, then put on and adjust headset, wind and set the clock and the red hands, then crank. The Concord AGX with extra cranking amps really helps. When I put it in, I could've sworn it spun the prop fast enough to taxi. Just be sitting down when you check the price . . . If it helps, I put it back in Dec 2010, and still going strong at annual last month. P.S.--I never used a battery tender of any sort. But I did buy a cell switch, eliminated those snowy drives to the airport to unplug the engine heat when I couldn't fly. Overnight is wonderful, but realistically, for a breakfast run I'd call the switch when I got out of bed and always cranked immediately. Edited February 28, 2016 by Hank Quote Link to comment Share on other sites More sharing options...
Godfather Posted February 28, 2016 Report Share Posted February 28, 2016 Cold starts always take some planning... imo a battery minder is critical to keep the batteries fresh. I switch batteries (connected to the charger) after every flight. Flying out of a unheated hanger I find a two heater setup works best. A 750 watt heater is used inside the plane and another 750 watt heater is ducted to the air intake. This keeps everything inside and out at ~80 degrees. A pager box is used to turn the heater on and off but the battery charger stays on all the time. I think it would be a good idea to test the battery. Call the manufacturer to learn the proper procedure. I have a setup using a fluke meter to test the voltage, a inline amp meter, and a overhead projector bulb to provide a constant load (of the proper amperage) on the battery. If the battery last long enough (50 mins for the Gill I use) while staying above the min voltage (given by the batt man) you are good to go. Remember after the discharge you need to immediately put the battery on a low (3-4 amp) charger. Quote Link to comment Share on other sites More sharing options...
Shadrach Posted February 28, 2016 Report Share Posted February 28, 2016 As Clarence suggests, tender connected hot side of battery relay. the plug can be connected through the opening to the step. l've a Concord dry cell. Even in the coldest of cold it'll crank the high speed starter with ease even after being dormant for 6 weeks. I didn't even bother with the tender this year because the battery holds a charge above 12.5V or more at the bus even after sitting for weeks in sub freezing temps. Quote Link to comment Share on other sites More sharing options...
blaine beaven Posted February 28, 2016 Report Share Posted February 28, 2016 I imagine I'm in colder temps than most. I park outdoors and have an engine cover. I have a small car heater I put in through the cowl opening on my J, plus an oil pan heater. For the interior I have a large space heater. For the battery, I have an "intelligent" trickle charger that only charges if the battery is low. I use a cigarette lighter plug and it is plugged into the dash to feed the battery. The biggest issue I have away from home base is some of the northern airports can't support that much amperage on one breaker, with a 50' extension cord. Sent from my iPhone using Tapatalk Quote Link to comment Share on other sites More sharing options...
M20F Posted February 28, 2016 Report Share Posted February 28, 2016 25 minutes ago, blaine beaven said: The biggest issue I have away from home base is some of the northern airports can't support that much amperage on one breaker, with a 50' extension cord. I highly reccomend http://www.amazon.com/Yamaha-EF2000iS-Starting-Portable-Compliant/dp/B002RWK9N2/ref=sr_1_1?ie=UTF8&qid=1456677420&sr=8-1&keywords=yamaha+generator there are a few others around here using this model as well. For OP I park outside in a colder place than TZR and never have cranking issues even after 2-3 weeks sitting. It sounds like as suggested you need a new battery. 1 Quote Link to comment Share on other sites More sharing options...
Marauder Posted February 28, 2016 Report Share Posted February 28, 2016 25 minutes ago, blaine beaven said: The biggest issue I have away from home base is some of the northern airports can't support that much amperage on one breaker, with a 50' extension cord. I highly reccomend http://www.amazon.com/Yamaha-EF2000iS-Starting-Portable-Compliant/dp/B002RWK9N2/ref=sr_1_1?ie=UTF8&qid=1456677420&sr=8-1&keywords=yamaha+generator there are a few others around here using this model as well. For OP I park outside in a colder place than TZR and never have cranking issues even after 2-3 weeks sitting. It sounds like as suggested you need a new battery. I have the Yamaha unit as well. When I'm traveling in the winter, I carry it with me along with a ceramic heater. I put the unit under the wing and run a power cord to the engine (Reiff heater) and another cord for the ceramic heater in the cabin. I then chain it to the main gear. Sent from my iPad using Tapatalk 1 Quote Link to comment Share on other sites More sharing options...
kevinw Posted February 28, 2016 Report Share Posted February 28, 2016 Here's what I do in the cold Iowa winters and I've never had a problem with starting. I leave the engine plugged in 24/7, use a Kennon Cover, a battery minder and finally a portable heater kept on low to keep the cabin and avionics warm. For those of you that have TKS, the battery minder plug works well in the TKS door. I also installed a Concorde battery last year. My Gill wasn't very old but I wanted the extra cranking power and the Concorde is noticeably better. Quote Link to comment Share on other sites More sharing options...
Danb Posted February 28, 2016 Report Share Posted February 28, 2016 Kevin what kind of tug is that? Quote Link to comment Share on other sites More sharing options...
yvesg Posted February 28, 2016 Report Share Posted February 28, 2016 Hard to beat Canadian winters for cold weather operations... I installed many years ago a trailer connector the same way Clarence mentioned above. It is fused. I keep the battery topped up by connecting a low current solar panel to it. No need for electrical outlet power around. I will post picture later... now the aircraft is in annual. I also use a 35000 BTUs propane heater to warm-up the engine before startup. Pipe goes on the left side cowl flap opening. The coldest I flew was -30 C on ground. Wife has said... not anymore. Yves Quote Link to comment Share on other sites More sharing options...
Godfather Posted February 28, 2016 Report Share Posted February 28, 2016 (edited) I also use the tks fill door to attach the battery minder with the same plug type as Kevin (two of them, one for each battery). Edited February 28, 2016 by Godfather Quote Link to comment Share on other sites More sharing options...
M20F Posted February 28, 2016 Report Share Posted February 28, 2016 43 minutes ago, Danb said: Kevin what kind of tug is that? http://www.robotow.com/ 1 Quote Link to comment Share on other sites More sharing options...
ArtVandelay Posted February 28, 2016 Report Share Posted February 28, 2016 Doesn't connecting a plug to the battery require a approval of some kind? Quote Link to comment Share on other sites More sharing options...
kevinw Posted February 29, 2016 Report Share Posted February 29, 2016 Kevin what kind of tug is that? Sidewinder. Just got it a few weeks ago. Sent from my iPhone using Tapatalk Quote Link to comment Share on other sites More sharing options...
kevinw Posted February 29, 2016 Report Share Posted February 29, 2016 Doesn't connecting a plug to the battery require a approval of some kind? It's actually tied into the Tanis heater so it's only hot when the Tanis is plugged in. Sent from my iPhone using Tapatalk Quote Link to comment Share on other sites More sharing options...
Guest Posted February 29, 2016 Report Share Posted February 29, 2016 From school, I remember that a lead acid battery it 100% efficient at 80F. Therefore a battery warming blanket plus engine heating would be the next best solution to a hangar. Clarence Quote Link to comment Share on other sites More sharing options...
steingar Posted February 29, 2016 Author Report Share Posted February 29, 2016 Thanks for the replies guys, Mooneyspace is always a great source of info! I've got the take the bird in to address some squawks, I'll have the battery tested and start looking into connecting something to the battery relay (once I figure out where it is). This is a really stupid problem to have. I didn't think the battery issues would be so bad since there's not a big a voltage drop, the battery is in the front with the engine. I spent a fair bit of coin to get an engine heater that's on its own thermostat. It maintains the engine bay at about 70 degrees F, and doesn't get to hot to hold in your hand. Kind of expensive, but well worth it. I just keep cowl plugs in and cover the nose with some cheap moving blankets. If I can keep the battery charged up I have no problems at all starting on the coldest day. Quote Link to comment Share on other sites More sharing options...
Marauder Posted February 29, 2016 Report Share Posted February 29, 2016 From school, I remember that a lead acid battery it 100% efficient at 80F. Therefore a battery warming blanket plus engine heating would be the next best solution to a hangar. Clarence Doc -- I'm quoting you since I think I read on one of these threads you mentioning taking the charging lead out the step hole. Currently, if I know I won't be flying for the week, I will pull the avionics bay cover and hook up my BatteryMinder to the terminals. I think Brett (bnicolette) posted an set of instructions showing how to bring the leads up to the hat rack area. I would love to find a way to run the charging lead through the step area. My step was removed and I currently have metal foil tape covering the hole. Any pictures of mounting the leads this way? Sent from my iPad using Tapatalk Quote Link to comment Share on other sites More sharing options...
Guitarmaster Posted March 8, 2016 Report Share Posted March 8, 2016 (edited) On February 27, 2016 at 5:59 PM, M20Doc said: Your battery sounds like it's due for replacement. As for the battery tender, why not connect it to the "hot" side of the master relay with an inline fuse. Clarence That's exactly what I did. The only difference was I connected it to a 12V power outlet. This way, the kids can play their games in the back and when it sits, it charges through the outlet. It's rated for 10A, so pushing 3A through it is nothing. Two bird theory! P.S. You kind of have to ignore the 'porno red' carpet. Edited March 8, 2016 by Guitarmaster 1 Quote Link to comment Share on other sites More sharing options...
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