Often the problem is a bad ground/ corroded ground from the engine to the engine mount... A high resistance connection causing problems.
________________________________ From: Hartmut Beil <[email protected]> To: Techlist Ercoupe <[email protected]> Sent: Fri, June 18, 2010 3:23:38 AM Subject: RE: [ercoupe-tech] batteries Linda. My experience with batteries is that a battery that is dying can crank the starter fine for a few rotations, but is still source of trouble. A Generator/regulator that is loading the battery properly can create the same effect. When all 3 parts of the system are in good working order, you won't experience the problems you are describing. As a matter of fact, I was jump starting cars with my 12 Amp/h Motorcycle Battery with no problems. It is not the size of the battery that matters, it is the cranking power that it can develop. Understandable a battery with a dying cell will develop little cranking power, as are some batteries that are not designed for that purpose. A good 12 amp battery should be able to start your engine as well as the 24 amp one or the 35 amp one. If you have these intermittent problems , I am hesitating to come to fast conclusions that the battery is not big enough. This is the logic of the inexperienced. It is usually either the starter itself or the charging system. Of course one has to verify first that the battery itself is good. I am afraid you mechanic wants to fix a problem from the wrong side at your costs. Hartmut ________________________________ To: ercoupe-tech@ yahoogroups. com From: laspr...@cox. net Date: Thu, 17 Jun 2010 16:09:08 -0700 Subject: [ercoupe-tech] batteries What John wrote below helps a lot to understand the relationship of battery & generator. The problem I've had recently has not related to running enough electrical items in flight, rather, it has been battery capacity for cold starts: e.g. when my local A&P ran a bunch of "test starts," such as when he was adjusting the pull-starter he tried it out a bunch of times, or when he cleaned the spark plugs and was testing whether that smoothed-out how the engine was running. Then when I went to fly next, there was not enough power to start up. Yesterday, he had to give it a "jump start," but after I flew 45 min. to my destination, did 3-4 starts & run-ups there for the prop-balancing guy, and then it sat for 2-3 hrs. but still started fine for me to fly home. John (et al.), can you please address battery capacity for cold starts? Is it correct that a Concorde 35 will be better for this purpose than a 25? The A&P wants me to get a 35 (and, Hartmut: he says a field approval is no problem, and he'll measure the box for fit, before buying it.) Is a 35 better for my purposes than a 25? Other than the few lbs. extra weight, am I asking for any kind of additional problems if I get the 35? My 414-C has a C-85 and a generator, not an alternator. Linda N3437H (Sky Sprite) L.A. 1a. Re: batteries Posted by: "John Cooper" j...@skyportservice s.net Date: Wed Jun 16, 2010 6:16 am ((PDT)) On 6/14/2010 7:31 PM, Todd Fischer wrote: > Reading the Univair memo it sounded like the older generators just > couldn't handle charging the larger batteries and only approved the > RG25 batteries. > > This is a misconception. The larger battery has more capacity, so it will take longer to discharge, as well as longer to recharge, but, unless you continually discharge it, which means your constant electrical load exceeds the generator capacity, it will remain charged the same as a smaller battery. OTOH, if you are exceeding the capacity of the generator on a regular basis, the smaller battery will go flat faster. If the RG-35 battery is in good shape, and you charge it up (once), and you do not exceed the capacity of the generator with your electrical load, then the battery will work fine. As an aside, the constant load on the electrical system should not exceed 80% of the generator capacity. Constant load includes comm recievers, nav radios, transponders, nav lights, etc.; everything that is not intermittent, e.g. landing lights, flap motors, gear motors, comm transmitters, etc. -- John Cooper Skyport East www.skyportservices .net ________________________________ Your E-mail and More On-the-Go. Get Windows Live Hotmail Free. Sign up now. Often te
