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Back up alternator

togaflyer

Well Known Member
When the time comes Im concidering installing e/p mags, and an all electrical panel. Instead of two batteries, I have been looking into the B and C back up alternator. Puts out a minimum of 15 amps at 2000 RPM. Adds around 7 pounds forward. It is gear driven and installs on one of the engines mag attachment points. Has anyone installed this set up. Are there issues. Thanks.
 
Mag hole?

Correct me if I am mistaken but isn't the back up alternator installed in the
Vacuum accessory hole?
I believe many have installed a back up alternator instead of 2 batteries.
I am a 2 battery kind of guy.
 
Lots of people using this setup, including me for the last 5 years. Actually the backup alt. installs on the vacuum pad. If you set the backup regulator 0.5 volts less than the primary regulator, it comes online after the primary alt. fails and battery voltage begins to drop. Happens with no pilot input. My all glass -10 will maintain adequate batt. voltage forever, as long as I don't need continuous pitot heat or landing lights. I have already had 2 primary alt. failures in 500 hrs.; both times I continued to my destination without difficulty.
 
You are right it goes on the vacuum pad. One of the electronic ignitions I looked at uses a mag slot. Got them confused. Did the added weight on the engine impact the cg at all. Also, when the stand by kick on, does it tie in with the battery or does it just support the buss bar. Or was that a dumb question to ask.
 
There are backup alternators that use the vacuum pad. One is from B&C and the other is from Plane Power. The B&C has been on the market for quite awhile. The plane power unit is relatively new to the market, but has a higher capacity.

I have the B&C primarily because the plane power wasn't on the market when I purchased it. It requires an external regulator.

Your question about what it connects to was a dumb question.😃 it really depends on how you wire it. It depends on your electrical design and if you have an ebus.

I would recommend you read two documents. The first is the AeroElectric Connection by Bob Nuckolls. The other is the installation manual for the Vertical Power VPX. Even you don't purchase a VPX, it will help you understand some of the questions you are asking. Vertical Power also have some how to guides on their site that you may find beneficial. If this is new to you and you find it frustrating, I would recommend taking a serious look at the vpx product. It will make your life much easier.

B&C also has their install manuals only, so,you can see how to wire their alternator.

Once you read these documents, you'll be better prepared to start planning your electrical design.
 
B&C Main & Standby

I have the 60 amp B&C as my main alternator and the Standby B&C mounted on the vacuum pad. Haven't touched them in 800 hours. I have the regulators mounted in the sub-panel away from the heat of the engine compartment.

When you look at the B&C website the pricing is a little confusing if you just click on standby alternators because of the expensive STC versions that they sell for Cessna, Piper, etc. Looks like Spruce currently sells the standby for $494 plus the regulator at $193.

Andy
 
Backup alternator

If your plan to use your 10 for IFR and it is all electric, then you should consider 2 batteries. Set up 2 electrical systems using a standby alternator as primary on the second circuit and install a cross-tie between them. This gives you great redundancy. It is in Nuckolls book.

The 10 uses a lot of current with everything being electric. The best value in having 2 batteries is the ability to keep going if you have a hard start and run down your battery. Close the cross-tie and you have more cranking amps. It has saved me a couple times.

The p-mag does not need a battery but don't count on it being available. If you go to 2 electronic ignitions then I would strongly advise a second battery.
 
I chose to go dual alternator/single battery setup (extra battery weights a lot!), B&C for both units, no problem with either unit in over 1500 hrs. I do replace the battery every 2-3 years.
 
Once again great information from great people. The plane will be set up for IFR. I have looked into the VPX. It looks like a great set up, but I have concern with my system depending on one box. Is there redundancy. What happens in that rare instance that unit fails. Do you loose your systems or ?

Right now Im preparing my shopping list for Sun n Fun and Oshkosh. Its gonna be an expensive year!
 
If your plan to use your 10 for IFR and it is all electric, then you should consider 2 batteries. Set up 2 electrical systems using a standby alternator as primary on the second circuit and install a cross-tie between them. This gives you great redundancy. It is in Nuckolls book.

The 10 uses a lot of current with everything being electric. The best value in having 2 batteries is the ability to keep going if you have a hard start and run down your battery. Close the cross-tie and you have more cranking amps. It has saved me a couple times.

Actually, if you read Nuckolls' postings of the past year or 2, he seems to be leaning towards 2 alternators and 1 well-maintained battery.

How close are you to flying? If it is a year or more, I would wait on making any panel purchases. Your expensive gear could be out of date before you get a chance to use it.
 
What's the benefit of two batteries over one larger battery of the equivalent size?

Bevan
 
What's the benefit of two batteries over one larger battery of the equivalent size?

Bevan

In my case, I can light up the panel on the aux battery, and start the engine off the main battery. The panel is up and running before the engine starts, I get instant readings for RPM, Oil pressure etc. no waiting while the EFIS warms up---and no brown out of the EFIS.

Also, as someone already mentioned, if I run down the main, there is a cross tie relay to send aux battery current to the starter.

Basically I have two parallel systems, Smaller battery and alternator to run the avionics buss directly, with above mentioned start cross tie. And big battery and big alternator to run starter, and all systems-----the big/main feeds through a Schottky diode to run the avionics, but everything else is fed directly from the main buss.

Works well for me, besides when I bought the project both alternators and both batteries were included-----------all I did was figure out a way to use them. Too cheap not to, when they were in hand.
 
What's the benefit of two batteries over one larger battery of the equivalent size?

Bevan

Separate batteries When properly bussed provide independence, and redundancy, which in the end increases the reliability of electrical power to flight critical systens.
 
Once again great information from great people. The plane will be set up for IFR. I have looked into the VPX. It looks like a great set up, but I have concern with my system depending on one box. Is there redundancy. What happens in that rare instance that unit fails. Do you loose your systems or ?

Right now Im preparing my shopping list for Sun n Fun and Oshkosh. Its gonna be an expensive year!

It depends on how you design your electrical system. I have a VPX, as well as a completely independent Ebus. Mine can fail and I can continue to fly without much of an impact.

I would recommend reading the install manual. It talks about dual alternators, dual batteries, ebus, backups, failures, etc. good information even if you don't decide to buy one.
 
My plan is to have the plane operational by end of this year. We sold our other plane, so we have the funds to complete the new one. After 20 plus years of owning planes, we are feeling the loss. A 50 minute flight compaired to a 6 hour drive to places we go has momma even cracking the whip to get the plane going. I want to lay plans for systems now so I can keep a good flow going. Back up alt will be a go, gonna check into the VPX and check out the manaul as Bob sugested too.
 
If your plan to use your 10 for IFR and it is all electric, then you should consider 2 batteries. Set up 2 electrical systems using a standby alternator as primary on the second circuit and install a cross-tie between them. This gives you great redundancy. It is in Nuckolls book.

The 10 uses a lot of current with everything being electric. The best value in having 2 batteries is the ability to keep going if you have a hard start and run down your battery. Close the cross-tie and you have more cranking amps. It has saved me a couple times.
I have the exact setup described above. It is known as a "Z-14" in Bob Nuckolls Aeroelectric forum. It is a well evolved design that you are invited to copy as I did. I use a B&C 40amp and the B&C standby with 2 regulators. SOP is to start with both batteries and busses linked, then to run with them unlinked for the rest of the flight. That way any sudden or slow motion failure like an alternator or battery can be detected, isolated and bypassed as needed.

I file and fly IFR almost exclusively and feel pretty much bullet proof with a 2 alternator, dual battery, dual bus installation though I do run 2 old school mags.
Actually, if you read Nuckolls' postings of the past year or 2, he seems to be leaning towards 2 alternators and 1 well-maintained battery.
That's true. He thinks his Z-14 is overkill in most applications.

I had a very specific desire to be able to run my (3) EFIS panel for extended periods on the ground before engine start without having to worry about having enough juice to start the engine when desired. The Z-14 lets me do that without concern.

I was surprised by just how much juice a fully electric, (3) EFIS panel needs and just how fast it will run a battery down below what is required for a say a cold engine, cold weather start. The light weight start shipped with my IO-540 doesn't help the situation either. What I thought was going to be a convenience that I would occasionally take advantage of turned out to be a necessity for my normal flying.

I also found that the EFISs and the G430 did not deal with the sag in power when the engine starts and that it often resulted in these units re-booting. An inconvenience at best requiring re-entry of flight plans, damaging at worse on early software versions of my EFIS that didn't respond well to being interrupted during its IPL. I added TCW's Intelligent Power Stabilizer to prevent re-boots during start.
What's the benefit of two batteries over one larger battery of the equivalent size?
Benefit 1: You can use and run down one battery while preserving the other for engine starts
Benefit 2: If you don't maintain your battery well or let it run until a cell starts to fail, you won't get stuck on some remote ramp. You have a backup.

I run (2) Odyssey 680s.
 
FS-14B

Has anyone had issues with the rear shroud cracking and falling off the alternator? I have had to replace two in past 280 hrs with no real explanation why. We thought possible vibration but had prop balanced early on and it calibrated close to original. Is it possible the alternator has internal vibration? Thanks in advance for you thoughts or ideas!
 
If you're worried about running your battery down while cranking, get an electronic ignition :)

I love the simplicity of a single, modern, reliable battery. I'm using the Concorde battery per plans, and it's still going strong after 4+ years.

-Rob
 
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