How to Attach Battery Minder plane simply

[M20F-1968]

There have been some posts about this.  I recently found some electrical connectors that fit inside the external power connector box easily.  A fused harness can be made from Milspec wire, to come from the battery, through the space between the external power supply box and the aircraft skin, and be fitted with these connectors which are small, rated for the voltage/amperage needed, and allow easy closure of the connector-springed door.  

The maker of the connector is PowerWerx and can be found at https://powerwerx.com/

The connectors come in red and black and can be ordered pre-bonded together so it is just one click to connect to the airplane.  The same connector is placed on the wire from the Battery Minder.  They make an extension wire that has O ring connectors on one end and the automotive connector they use on the other end.  I used that cable to connect between the MIL Spec cable installed in the plane, to the Battery Minder itself.  That way you can leave the actual cable connected to the Barrery Minder unaltered.

[M20F]

If you are not flying enough for the battery to stay fresh, the battery will be will be the least of your issues. 

[Pinecone]

Your choice, but at the price and availability of aircraft batteries, a Battery Minder is a good idea.

[Andy95W]

4 hours ago, Pinecone said:

Your choice, but at the price and availability of aircraft batteries, a Battery Minder is a good idea.

Yes, but it’s also a way to fool yourself into thinking a marginal battery is still good.  It would suck to go on a trip, have your airplane sit on an FBO ramp for a week, and not start.

[Pinecone]

If you battery is so bad it has a hard time starting, it is well past needed to be replaced.  That is why you do capacity checks.

[DonMuncy]

11 hours ago, Andy95W said:

Yes, but it’s also a way to fool yourself into thinking a marginal battery is still good.  It would suck to go on a trip, have your airplane sit on an FBO ramp for a week, and not start.

I agree with that idea. It happened to me once. But I think Battery Minders are a good idea. My thought is that, periodically, you should disconnect the Battery Minder for a week and check to see if it will start the plane easily. (Is that a CB's battery capacity test?)

[M20F-1968]

Is there an affordable battery capacity tester?  At 12 volts, what should the load be to drain the battery how far?  The more the load, the more the capacity tester costs.  Is a 150 amp load for 1 hour equal to testing with a 50 amp load for three hours?

John Breda

[EricJ]

2 minutes ago, M20F-1968 said:

Is there an affordable battery capacity tester?  At 12 volts, what should the load be to drain the battery how far?  The more the load, the more the capacity tester costs.  Is a 150 amp load for 1 hour equal to testing with a 50 amp load for three hours?

John Breda

The instructions for how to do a capacity test are in the manuals for the various batteries.    The Concorde CMM says to drain it from a full charge (per the instructions) at the capacity rate (e.g., 35A for a 35Ah battery), until it reaches a particular voltage, 10V for a 12V battery or 20V for a 24V battery.   The amount of time it takes to do that determines the capacity.

How to charge it before the test, do the test, recharge it, or recondition it if it doesn't pass >90% are all in the Concorde Component Maintenance Manual.    Gill has a similar manual as well.

Some of us are using smaller controlled loads because a full 35A (for example) constant load is more difficult to get.   It is possible to adjust the results to compensate for the reduced load.

[Fritz1]

minder is a good idea, can't hurt, battery might just live longer, capacity test is part of annual

[M20F-1968]

33 minutes ago, EricJ said:

The instructions for how to do a capacity test are in the manuals for the various batteries.    The Concorde CMM says to drain it from a full charge (per the instructions) at the capacity rate (e.g., 35A for a 35Ah battery), until it reaches a particular voltage, 10V for a 12V battery or 20V for a 24V battery.   The amount of time it takes to do that determines the capacity.

How to charge it before the test, do the test, recharge it, or recondition it if it doesn't pass >90% are all in the Concorde Component Maintenance Manual.    Gill has a similar manual as well.

Some of us are using smaller controlled loads because a full 35A (for example) constant load is more difficult to get.   It is possible to adjust the results to compensate for the reduced load.

What is the mathematical calculation used to adjust the time, ending discharged amount, the resulting voltage used to determine the condition of the battery?  I ask this because 12V battery capacity testers are available which have a lower load maximum which also reflects in a lower cost.

John Breda

[tmo]

52 minutes ago, M20F-1968 said:

Is there an affordable battery capacity tester?  At 12 volts, what should the load be to drain the battery how far?  The more the load, the more the capacity tester costs.  Is a 150 amp load for 1 hour equal to testing with a 50 amp load for three hours?

John Breda

https://mooneyspace.com/topic/46793-battery-capacity-testing-review-of-dtl150-a-35-battery-capacity-tester

[FlyingDude]

Unlike automobiles fitted with immobilizers, door unlock stuff, etc. that drain their batteries constantly, aircraft batteries are not drained during resting periods thanks to the master solenoid.  There are no direct-battery loads except for few exceptions like electronic ignition units, whose leakage is really low.  Battery self discharge is also not so prevalent.  Maybe there are cases out there with corroded connections between the alternator and the battery such that the alternator voltage drops down to the battery voltage by the time it reaches the battery terminals.  In that case, even if you fly regularly, you won't be charging your battery and battery minder might be the only thing that keeps your battery charged.  Check your battery ammeter after engine start up (if you have an alternator) or after take off (if you have a generator) to see if the battery is receiving any juice...

[blaine beaven]

Living somewhere that sees below freezing temperatures nearly 50% of the year, if I didn’t use a battery minder I would be lucky to be able to start my plane in -20C, regardless of engine preheat. 

[Joshua Blackh4t]

I'll be fitting a quick plug to mine sometime soon.

Its not so much the minding, but doing short flights/joyflights and still having the generator.

I want to attach a small solar panel to my aircraft cover and then its just a few clicks and voila, its full next day even after the worst hot start followed by a short trip home.

The battery is in the back of mine so the plan is to put the plug on the hat rack, plug the charge controller there, then the panel will be on the cowling and attached via an extension running out the pilots vent.

It won't be left on all the time, but just when needed.

Much cheaper than an alternator conversion.

[Pinecone]

Just make sure the charge controller is doing the right thing for your AIRCRAFT battery.  

Most are designed for car batteries.

[FlyingDude]

1 hour ago, Pinecone said:

Just make sure the charge controller is doing the right thing for your AIRCRAFT battery.  

Most are designed for car batteries.

I've been curious.  What's the difference in technical terms?  (I'm aware of the marketing pitch.) 

Thanks.

[Andy95W]

7 hours ago, blaine beaven said:

Living somewhere that sees below freezing temperatures nearly 50% of the year, if I didn’t use a battery minder I would be lucky to be able to start my plane in -20C, regardless of engine preheat. 

I’ve flown my Mooney at -20°C (-4°F) way down here in Michigan and didn’t have a problem, and I’ve never had a battery minder.  I’m not saying I can compare my winter experience to yours, but we regularly see extended stretches when the temperature never gets above -12°C.

I do fly regularly (every 7-10 days), and I do preheat when it’s below freezing.

[PeteMc]

6 hours ago, Pinecone said:

Most are designed for car batteries.

I'd also be curious what the difference is.  I've now got power, so a battery minder may be in the future.  

Pending how much I fly, not sure if it would be worth it or not.  

 

[EricJ]

42 minutes ago, PeteMc said:

I'd also be curious what the difference is.  I've now got power, so a battery minder may be in the future.  

Pending how much I fly, not sure if it would be worth it or not.  

 

Gill and Concorde used to both do presentations at our local IA seminars, and they both would make the case for using an aircraft-specific minder compatible with their batteries as opposed to an automotive unit.    Aircraft batteries are made to handle faster changes in temperature and ambient pressure than automotive batteries have to deal with, so apparently the differences in construction and chemistry benefit from different maintenance strategies and techniques.    I can't find my notes from the seminars, which were about five years ago, but they were both pretty adamant about not using automotive minders.

[Fly Boomer]

4 hours ago, PeteMc said:

Pending how much I fly, not sure if it would be worth it or not.  

Compare the cost of a BatteryMINDer with the cost of a Concorde.

[PeteMc]

1 hour ago, Fly Boomer said:

Compare the cost of a BatteryMINDer with the cost of a Concorde.

Exactly, that's all part of the evaluation.  If I'm flying enough to keep the battery charged, which is also good for the engine, then why spend the money for the battery minder. 

One could also just add a descent battery trickle charger with a remote switch and in the winter turn it on in the morning if you were going to go flying.  It would warm the battery, which should already have a good charge, so you're good to go when you get there.  No need for the added cost of the "MINDER" part to constantly calculate if it should turn the charging function On or Off.

Edited October 26, 2023 by PeteMc

[EricJ]

1 hour ago, PeteMc said:

Exactly, that's all part of the evaluation.  If I'm flying enough to keep the battery charged, which is also good for the engine, then why spend the money for the battery minder. 

One could also just add a descent battery trickle charger with a remote switch and in the winter turn it on in the morning if you were going to go flying.  It would warm the battery, which should already have a good charge, so you're good to go when you get there.  No need for the added cost of the "MINDER" part to constantly calculate if it should turn the charging function On or Off.

Some of the main benefits of a proper minder are monitoring the condition of the battery and performing desulfating cycles, which won't happen during normal use or with a trickle charger.

[PeteMc]

6 hours ago, EricJ said:

and performing desulfating cycles

Okay... But there are also inexpensive de-sulfator pulse chargers.  I would need to do some research, but from memory I think if I turned one of those on every so often on a cold morning to warm the battery I would get the same result of a battery that was ready to crank, have some de-sulfator benefits and and still cost a lot less than a battery minder.  

[Joshua Blackh4t]

I can understand an aircraft battery needing a different system to keep them maintained. Maybe different amounts of lead needs different frequencies etc.

But what I want to do is simply charge it. As long as its not too fast, or too high, I can't see it hurting it. Certainly better than leaving it 3/4 charged and then draining it further to start the engine.

Besides, batteryMINDers don't have a solar power version. 

[Pinecone]

If you just want to charge a low battery, any charger will work, as long as you watch it and only leave it on long enough to charge the battery.

Battery Minder (and Battery Tender for automotive) to things to increase the useful life of the battery.  And the voltages used vary by the construction of the battery, thus the specific units for cars, Concorde and Gill.

Using a trickle charger to warm the battery and top it off will work fine.  Until you get busy, don't go flying and leave it on too long and kill your battery.

Your choice,  Not buying a Battery Minder is cheaper, until things go wrong and your system kills an $800 battery.  My chocie is to get the unit designed to do the right thing, and let it do what it does.