Houman Posted April 17, 2014 Report Share Posted April 17, 2014 Hi, Trying to test fly the M20K I'm looknig to buy, but plane has been in a hangar for 5 months without being flown, so battery is dead. I think the battry is in the back of the fuselage, but wondering beside a normal car battery charger, what would one do to charge the battery. The local AME want's to replace the battery, but I think just a recharge should be fine... any advice is welcomed. Quote Link to comment Share on other sites More sharing options...
MB65E Posted April 17, 2014 Report Share Posted April 17, 2014 What type of battery? How old? Manufacture and voltage? If the water levels are fine, I would remove the battery and put it on a slow 2amp( correct voltage) charger and watch the amperage during the day. If it takes a charge, a good 12v battery should be almost 13v on a volt meter. Batteries are funny, with out actually load testing them, they will give false impressions. Good luck, -Matt Quote Link to comment Share on other sites More sharing options...
1964-M20E Posted April 17, 2014 Report Share Posted April 17, 2014 Any battery charger should work fine assuming the system is 12V which I believe it is but double check. Connect the charger and let it charge at a low rate 2 to 4 amps and let it charge for a day or so. In 5 months the battery should not have discharge that terribly much unless it is getting old. Check the electrolyte level in the battery before charging make sure it is at the proper level. Quote Link to comment Share on other sites More sharing options...
N601RX Posted April 17, 2014 Report Share Posted April 17, 2014 Completely Discharging a battery, especially a older one and leaving it discharged for any length of this will permanently damage it. Let the current owner replace it now so you don't have to in a month or two. Quote Link to comment Share on other sites More sharing options...
DonMuncy Posted April 17, 2014 Report Share Posted April 17, 2014 Depends on whose nickel. If your aren't sure you are going to buy it, charge it, or borrow one from someone and temporarily swap it. After you buy it, replace the battery. Quote Link to comment Share on other sites More sharing options...
carusoam Posted April 17, 2014 Report Share Posted April 17, 2014 Higher the experts... The money spent, will be worth it. 1) don't know where the battery is... 2) don't know the voltage of the electrical system... 3) don't know how to charge a plane's battery... 4) current plane is a M20L.... Skynewbie, is that you? you're back under another name? A 231 is a complex, high performance aircraft, there is much to know after the engine starts... On a serious note.... Let the owner do the work... Or his mechanic. Mechanics are trained in charging and load testing batteries. Whatever you decide, charge or replace. There is too much responsibility assumed by doing it yourself. Anything that is dead or broken is best not to be caused by the potential buyer. Batteries die, leak acid, split open... A whole bunch of problems... In the end you will want a new Concord battery anyway. Who is going to fly the plane? The owner, while you ride shot gun? Best regards, -a- Quote Link to comment Share on other sites More sharing options...
larryb Posted April 17, 2014 Report Share Posted April 17, 2014 Most likely the battery needs to be replaced. Soon after I bought my plane I accidently knocked the interior light switch and killed the battery. It was only dead a few days, but would not hold a charge after that and had to be replaced. You may get it to charge enough to start the plane but the battery won't have the proper reserve capacity. That means the battery won't last long at all if the alternator has a problem. Quote Link to comment Share on other sites More sharing options...
chrisk Posted April 17, 2014 Report Share Posted April 17, 2014 Ok, who else has left the master on? I know I am not the only one. I did it once on my first plane, and now I am paranoid about checking it. On the topic of batteries. Let the current owner deal with the problem. If he wants to sell the plane, he will make sure it will start. For negotiations, you can get a new RG-35axc for $265 from Chief. And to perhaps start a debate, BatteryMinder sells a specific charger for aircraft batteries, that is about $50 more than the equivalent car charger. I just assumed this was marketing BS, but Aviation Consumer seems to think it is worth the extra dollars. And the newer chargers have a desulfator that may help a near dead battery (one that will not hold a charge well). Here is a video on a desulfator. https://www.youtube.com/watch?v=DX1OaMYp6Kw Quote Link to comment Share on other sites More sharing options...
DonMuncy Posted April 17, 2014 Report Share Posted April 17, 2014 If you leave your strobe switch on at all times, you will have a hard time leaving your master switch on without noticing it. If you use a timer like I designed an built for my plane, it is impossible to run the battery down by leaving the cabin and/or baggage area lights on. Quote Link to comment Share on other sites More sharing options...
Recommended Posts
Join the conversation
You can post now and register later. If you have an account, sign in now to post with your account.