M20TN_Driver Posted November 2, 2022 Report Share Posted November 2, 2022 Hi all. I have not swapped batteries in my plane since I bought it a few years ago. I am not having any issues, but they are getting pretty old---one is almost 10 years old (#2). I was looking at possibly replacing the batteries in my plane as they are getting a bit old. When I looked in the logbook, I see entries for two different batteries being installed one battery (#2) is a Concorde RG24-15 and the other (#1) is a Concorde RG24-11. When I look in the POH the only thing it says is that the plane is equipped with "two 24v 10amp hour" batteries. However, when I look on Concorde's website it appears that both of these batteries are approved for my plane. So my questions are: Should they both be the same? Does it cause any issues if one is a bit different from the other? If I am replacing would it be OK to just purchase two of the RG24-15 given they are the same dimension, but with a bit more power (also slightly heavier)? Quote Link to comment Share on other sites More sharing options...
LANCECASPER Posted November 2, 2022 Report Share Posted November 2, 2022 2 hours ago, M20TN_Driver said: Hi all. I have not swapped batteries in my plane since I bought it a few years ago. I am not having any issues, but they are getting pretty old---one is almost 10 years old (#2). I was looking at possibly replacing the batteries in my plane as they are getting a bit old. When I looked in the logbook, I see entries for two different batteries being installed one battery (#2) is a Concorde RG24-15 and the other (#1) is a Concorde RG24-11. When I look in the POH the only thing it says is that the plane is equipped with "two 24v 10amp hour" batteries. However, when I look on Concorde's website it appears that both of these batteries are approved for my plane. So my questions are: Should they both be the same? Does it cause any issues if one is a bit different from the other? If I am replacing would it be OK to just purchase two of the RG24-15 given they are the same dimension, but with a bit more power (also slightly heavier)? No problems with an RG24-11 and an RG-24-15 in the same airplane. Since there's not much price difference definitely get the RG24-15 since you can never have too many amp hours (13 vs. 11). I have an account with Spruce and Textron. Textron has the best price now on the RG24-15, 681.28 each, free FedEx ground, but they do charge sales tax, like Spruce does. But the best price Spruce gives me is $759.50, with none in stock right now.. They are in stock at Textron. PM me if I can help out. Quote Link to comment Share on other sites More sharing options...
M20TN_Driver Posted November 2, 2022 Author Report Share Posted November 2, 2022 Much Appreciated. I have a buddy here who also has a textron account. Seems like they are the only ones that have stock. I can't find it anywhere, but I assume Starter is only tied into Battery #1 and Battery #2 is mostly to run backup, etc? Quote Link to comment Share on other sites More sharing options...
LANCECASPER Posted November 2, 2022 Report Share Posted November 2, 2022 3 hours ago, M20TN_Driver said: Much Appreciated. I have a buddy here who also has a textron account. Seems like they are the only ones that have stock. I can't find it anywhere, but I assume Starter is only tied into Battery #1 and Battery #2 is mostly to run backup, etc? Glad to hear you are hooked up with the batteries. I've said it before, but if we could have one thread on here where when we find who has the best deals on items, we could post, that could be a nice savings for the group. Either Battery 1 or 2 will start it and take care of everything else, but the GPU connection is on battery #1 and the panel switch has to be on Battery #1 if you are getting a GPU start. It's good to exercise both batteries but not good to switch batteries after start-up. On odd days I select Battery #1 on for start and use that day. On even days I use Battery #2. Quote Link to comment Share on other sites More sharing options...
M20TN_Driver Posted November 2, 2022 Author Report Share Posted November 2, 2022 Ah. Good advice. I’ll try that from now on. Quote Link to comment Share on other sites More sharing options...
EarthboundMisfit Posted November 3, 2022 Report Share Posted November 3, 2022 6 hours ago, LANCECASPER said: It's good to exercise both batteries but not good to switch batteries after start-up. On odd days I select Battery #1 on for start and use that day. On even days I use Battery #2. Curious what the concern is here? POH says to check positive charge for both BATs before takeoff, then choose the one you want to use for the flight: 1 Quote Link to comment Share on other sites More sharing options...
carusoam Posted November 3, 2022 Report Share Posted November 3, 2022 Dual battery systems are interesting… 1) In theory… they work perfectly… 2) In reality… things may be different… especially as everything ages… 3) If the two batteries are identical…. They both charge at the same time, the same way… one is trickle charging, while the other is at full charge… 4) They are connected together with a bridge… no digital electronics keeping them separate… a bunch of diodes… 5) If you use a BatteryMinder… you know the different battery chemistries charge differently… and you bought a charger specific to your battery… 6) Get to know your battery names… and how to best use them… 7) Battery +1 gets extra responsibilities… it is connected to the GPU, and the keep alive circuit…. 8) Use each battery evenly… odd/even days… or switch every flight… 9) The pre-flight check list rules the specific voltage test prior to flight… 10) Getting the batteries mixed and aged has a tendency to burn up a couple of diodes…. Not a common problem, but a pain when it happens… 11) If going with the extra capacity batteries… be sure to check the WnB… it may total a few extra pounds in the back… PP stuff I have heard around here… not a mechanic… Best regards, -a- Quote Link to comment Share on other sites More sharing options...
carusoam Posted November 3, 2022 Report Share Posted November 3, 2022 Saved the best for last… People have stopped changing batteries during the flight… for a few simple reasons… relays. The batteries are connected through a pair of relays… mechanical devices that are known to not wear with any precision or regularity… hitting the battery switch… it is supposed to have a delay mechanism… that closes one switch before opening the other… Switching technique matters… if you slowly push the switch… it cuts off both batteries as the switch moves through the middle… This system was designed prior to the instrument panel going full Digital… If your panel requires/likes electron flow…. Use the battery switch in flight when you need too… but, it is better to switch prior start.. PP thoughts only, not a mechanic or CFI… Best regards, -a- Quote Link to comment Share on other sites More sharing options...
LANCECASPER Posted November 3, 2022 Report Share Posted November 3, 2022 11 hours ago, EarthboundMisfit said: Curious what the concern is here? POH says to check positive charge for both BATs before takeoff, then choose the one you want to use for the flight: What @carusoam mentions. The people who write the POH aren't taking money out of their pockets to replace expensive relays. In practice, people who have replaced those relays find that it's better switch batteries when not under load. Quite a bit has been written on Mooneyspace about this. Quote Link to comment Share on other sites More sharing options...
M20TN_Driver Posted November 3, 2022 Author Report Share Posted November 3, 2022 Good Advice from all. I checked in with both TopGun Aviation out here (MSC) and Savvy. Both say that running two different types of battery isn't an issue, but then both said they would replace and make them both the same when the time comes ;-) Both also recommended the larger battery for replacement the RG24-15. Quote Link to comment Share on other sites More sharing options...
carusoam Posted November 3, 2022 Report Share Posted November 3, 2022 Definitely consider the XC extra capacity battery… 1) It weighs more 2) Has more amp-hours 3) Fits in the same foot print as the original battery 4) Why weighing more has an advantage… Long Bodies with the 310hp option have gotten heavier on the nose compared to the McCauley pulled variety… 5) More weight in the tail can offset the extra weight of the Hartzell hub… 6) Check out how much Charlie weight is in the tail still… you might need to trade useless weight for a more ‘useful’ weight… 7) Do the WnB math before ordering…. Batteries and their associated relays currently take months to arrive… getting different Charlie weights from the factory isn’t lightning fast either… 8) extra battery capacity and an E-bus make a great addition to the original LB design… PP thoughts only… work closely with your mechanic for WnB changes… Best regards, -a- Quote Link to comment Share on other sites More sharing options...
M20TN_Driver Posted November 3, 2022 Author Report Share Posted November 3, 2022 I pulled all of the power sources for my strobes and lights out of the tail when we did the LED install. I’m gonna call the 3-6 extra pounds a wash ;-) Quote Link to comment Share on other sites More sharing options...
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