Battery Replacement

[8233]

Anyone have any recommendations on what battery to use on a 120? I think mine is on it's last leg and I find the information out there confusing in terms of what is allowed and how involved you need to be with a mechanic to install it. STC, PMAs and so on.

Can someone share their experiences and battery used? I'm looking at a Concorde RG-25-XC. Is that the best option.

Thanks

[7509]

My 140 has had that type battery installed since 2008. I replaced it in 2017 as a precaution, but it was still holding a charge and extremely reliable. I would strongly recommend it. I still have the original 12 amp generator, but helping reduce the strain on the generator and battery was the replacement of all lights with LED, new avionics that draw a lot less amperage, and I do my best to fly at least twice a week to keep the battery charged.

[8233]

My 140 has had that type battery installed since 2008. I replaced it in 2017 as a precaution, but it was still holding a charge and extremely reliable. I would strongly recommend it. I still have the original 12 amp generator, but helping reduce the strain on the generator and battery was the replacement of all lights with LED, new avionics that draw a lot less amperage, and I do my best to fly at least twice a week to keep the battery charged.

I'm on a 20amp generator and just did the same thing with the LEDs. The battery still seemed to have limited capacity even though I have been flying it a lot. I went for a night flight and by the time I got to be ready for takeoff, it was evident the battery was running low.

I reviewed the log and the battery was replaced with a Gill in 2013. I suspect it's time for a new one and it wasn't probably a great battery to start with.

Thanks

[6643]

There have been a lot of reports of short life from Gill batteries. Both of my last two were 3 year batteries. I've heard much better reports from Concord owners.

When my last one went south I decided to replace it with an Odyssey battery. There is one that is PMA approved for use in several Piper models , the SBS J-16, and AC 43.13-2b has a section on battery installations. My IA and PMI both agreed that installation of that battery according to the procedures in AC43.13 constituted a minor modification and could be accomplished with nothing more than a log book entry.

[8233]

There have been a lot of reports of short life from Gill batteries. Both of my last two were 3 year batteries. I've heard much better reports from Concord owners.

When my last one went south I decided to replace it with an Odyssey battery. There is one that is PMA approved for use in several Piper models , the SBS J-16, and AC 43.13-2b has a section on battery installations. My IA and PMI both agreed that installation of that battery according to the procedures in AC43.13 constituted a minor modification and could be accomplished with nothing more than a log book entry.

I glanced through the AC and looked at the battery, I don't see the 120 and 140 called out and for the 170 and 195, they are saying it is a PMA as long as you have installed the STC'd battery box. Can you point me to the specific language in the AC that this was a minor mod? Just looking for how you got to that conclusion. I'm leaning toward the RG-25XC but reading some interesting things on the 170 forum that the XC version may not be a good idea with a generator less than 50amps (mine is a 20) although getting a alternator upgrade is on my short list.

Thanks

[6643]

Can you point me to the specific language in the AC that this was a minor mod? Just looking for how you got to that conclusion.

There is no specific language. Part 43 appendix A lists all major modifications and major repairs. By definition, if it is not listed, it is not major. So, unless changing the battery constitutes a change to the design of the electrical system, then it is minor. Both my IA and my PMI agreed that installation of this already-approved-for-some-aircraft battery did not rise to the level of a change to the design.

As far as the battery box, that is covered in AC43.13. One word of caution: do not use the Odyssey battery strap fastened to the back side of the existing battery box as this transfers the forces in a crash from the pushing on forward face of the box to pulling on the back, which is not nearly as strong. I used wooden spacers to transfer the force to the front and allow the lid to hold the battery down, as in the original design.

BTW, this reduced my weight by about 10 lbs and shifted my CG forward about 1/4". So, now I'm about 0.01 kts slower in cruise...

[8233]

Can you point me to the specific language in the AC that this was a minor mod? Just looking for how you got to that conclusion.

There is no specific language. Part 43 appendix A lists all major modifications and major repairs. By definition, if it is not listed, it is not major. So, unless changing the battery constitutes a change to the design of the electrical system, then it is minor. Both my IA and my PMI agreed that installation of this already-approved-for-some-aircraft battery did not rise to the level of a change to the design.

As far as the battery box, that is covered in AC43.13. One word of caution: do not use the Odyssey battery strap fastened to the back side of the existing battery box as this transfers the forces in a crash from the pushing on forward face of the box to pulling on the back, which is not nearly as strong. I used wooden spacers to transfer the force to the front and allow the lid to hold the battery down, as in the original design.

BTW, this reduced my weight by about 10 lbs and shifted my CG forward about 1/4". So, now I'm about 0.01 kts slower in cruise...

I wouldn’t mind seeing some pics of your installation if you are able to snap a few shots.

Thanks John.

[8233]

Well apparently my IA and PMI won’t agree with that approach so my IA insists on filing a 337 for the Concorde.

[6643]

A 337 is only required for a major repair or major alteration. Ask him to show you where it says changing brands of batteries is a major alteration.

Our PMI was also the inspector for our part 147 school. He always remarked about how many unnecessary 337s were filed. I guess the A&Ps look at it as CYA.

I suppose since Concorde has an STC, and STCs are approved data for major modifications, you could argue that a 337 is required... OTOH, if Concorde had a PMA for that battery to replace the original battery, then a log book entry would be sufficient.

[6298]

I have changed to Concord in several airplanes. They outlast the Gills and turn over faster. And, they fit in our battery boxes.