Load Testing Battery

[MikeOH]

5 hours ago, GeeBee said:

Is the power to a light switch always on? Think about it. One wire to that switch is always hot AND there is the ground wire.

As to explosion of hydrogen gas with an AGM, unlikely if you understand the technology. The Battery Minder cannot generate enough amps to make it happen.

The power to the charger is always on, too.  Not sure what you are trying to say about a simple light switch that supports your claim that it is more dangerous than a battery charger!

It would seem Concorde fails to understand their technology as well as you do, shown below is an excerpt directly from page INTRO-2 of their own RG Series CMM. But, what would they know, right?

Finally, the charger most certainly has enough current to generate a spark necessary to ignite hydrogen.

 

[GeeBee]

33 minutes ago, MikeOH said:

The power to the charger is always on, too.  Not sure what you are trying to say about a simple light switch that supports your claim that it is more dangerous than a battery charger!

It would seem Concorde fails to understand their technology as well as you do, shown below is an excerpt directly from page INTRO-2 of their own RG Series CMM. But, what would they know, right?

Finally, the charger most certainly has enough current to generate a spark necessary to ignite hydrogen.

 

Because the charger has internal protections both in terms of heat and current capacity that protect it. A light switch is only protected at the breaker box, not at the switch itself like a Battery Minder. To create massive amounts of hydrogen gas with an AGM battery you must charge it at very high rates, well above what a Battery Minder delivers. A Battery Minder fuse is set to blow at 15 amps, its normal output is 4 amps which will not cause hydrogen gassing at that charge rate. To gas out an AGM you have to charge at rates above 30 amps which is waaay above what the transformer on a Battery Minder can even generate.

AGM batteries are "recombinant". From the Concorde web site.:

Flooded lead-acid batteries have excess acid in each cell that prevents recombination of gas during charge. The gases generated during charge (hydrogen and oxygen) must be vented from the cell to avoid pressure build-up. This gas generation depletes the electrolyte of water so periodic replenishment of the water is required. AGM batteries have a “starved” electrolyte condition in each cell that allows recombination of gas during charge. Therefore, replenishing the electrolyte with water is not required. 

"During storage, charging, or discharging, RG Series batteries will release a small amount of hydrogen gas. The hydrogen gas must be diluted to prevent the possibility of ignition and/or explosion. Because the rate of hydrogen emission is very low, only minimal airflow is needed to dilute the hydrogen to safe levels. Most aircraft battery compartments have sufficient natural airflow that a separate air ventilation system is unnecessary. When the natural airflow is not sufficient, RG Series batteries are available with vent tubes for connection to air ventilation systems. Contact Concorde if further assistance is needed to determine the airflow requirements."

All this adds up to if you keep the charger below the battery and outside the battery storage area, there is no explosion risk because hydrogen rises and there is no significant hydrogen build up with an AGM battery due to its recombinant design. What  little hydrogen there is, is quickly dissipated. 

[MikeOH]

5 hours ago, GeeBee said:

Because the charger has internal protections both in terms of heat and current capacity that protect it. A light switch is only protected at the breaker box, not at the switch itself like a Battery Minder. To create massive amounts of hydrogen gas with an AGM battery you must charge it at very high rates, well above what a Battery Minder delivers. A Battery Minder fuse is set to blow at 15 amps, its normal output is 4 amps which will not cause hydrogen gassing at that charge rate. To gas out an AGM you have to charge at rates above 30 amps which is waaay above what the transformer on a Battery Minder can even generate.

AGM batteries are "recombinant". From the Concorde web site.:

Flooded lead-acid batteries have excess acid in each cell that prevents recombination of gas during charge. The gases generated during charge (hydrogen and oxygen) must be vented from the cell to avoid pressure build-up. This gas generation depletes the electrolyte of water so periodic replenishment of the water is required. AGM batteries have a “starved” electrolyte condition in each cell that allows recombination of gas during charge. Therefore, replenishing the electrolyte with water is not required. 

"During storage, charging, or discharging, RG Series batteries will release a small amount of hydrogen gas. The hydrogen gas must be diluted to prevent the possibility of ignition and/or explosion. Because the rate of hydrogen emission is very low, only minimal airflow is needed to dilute the hydrogen to safe levels. Most aircraft battery compartments have sufficient natural airflow that a separate air ventilation system is unnecessary. When the natural airflow is not sufficient, RG Series batteries are available with vent tubes for connection to air ventilation systems. Contact Concorde if further assistance is needed to determine the airflow requirements."

All this adds up to if you keep the charger below the battery and outside the battery storage area, there is no explosion risk because hydrogen rises and there is no significant hydrogen build up with an AGM battery due to its recombinant design. What  little hydrogen there is, is quickly dissipated. 

Blah, blah, blah….

Me thinks you doth protest too much!

In all of your blather you admit that even RG batteries generate hydrogen. Your whole diatribe falls flat when looking at Concorde’s clear warning that I posted previously.

The battery minder is a relatively complex system subject to many failure  modes. I don’t trust all the ‘protection circuits’ to function flawlessly while unattended. I’ve decided that getting an extra year out of my battery just isn’t worth the risk of fire, even if small.

[GeeBee]

I've kept 3 AGM batteries on continuous charge for almost 25 years in my boat and 15 years in my planes. That's a combined 40 years and a combined 105 battery years. Indeed just about everyone in the marine world including the Navy Seals go fast boats charge their AGMs which sit in enclosed bilges, unattended. Never heard of an explosion from them. 

[Shadrach]

13 hours ago, MikeOH said:

Blah, blah, blah….

Me thinks you doth protest too much!

In all of your blather you admit that even RG batteries generate hydrogen. Your whole diatribe falls flat when looking at Concorde’s clear warning that I posted previously.

The battery minder is a relatively complex system subject to many failure  modes. I don’t trust all the ‘protection circuits’ to function flawlessly while unattended. I’ve decided that getting an extra year out of my battery just isn’t worth the risk of fire, even if small.

Do consider that Concorde’s warnings are written to limit product liability rather than limit practical product application.  It’s my understanding that AGM batteries release Hydrogen and Oxygen when being charged but release far less hydrogen than conventional lead acid batteries. I can’t say for sure but based on the aircraft with which I’m familiar, somewhere around 50% of hangared aircraft are on a smart charger when not in use. I would bet nearly 100% of marine batteries are on a smart charger for an extend part of their lives. If the theoretical danger were prevalent as practical danger, we would see it manifested in the form of property loss..

[LANCECASPER]

I started using a Battery Tender in 1993 on a lead acid battery in a Mooney 231 - it was always outside of the airplane on the floor of the hangar. Later when I bought a 24v Mooney (M20M) with lead acid batteries it wasn't so easy to find that type of thing. I went through Gill batteries every couple years.  As soon as Battery Minders came out I've used them for over 20 years and the unit(s) have always been outside of the airplane. Never an issue. As soon as AGM batteries became available that's what I have switched to in my airplane, with the appropriate Battery Minder. Every car, motorcycle and riding lawn mower that I keep in my hangar is on a battery maintenance device. Before batteries shot up in price they paid for themselves many times over. Now even more so.

[GeeBee]

2 hours ago, Shadrach said:

I would bet nearly 100% of marine batteries are on a smart charger for an extend part of their lives. If the theoretical danger were prevalent as practical danger, we would see it manifested in the form of property loss..

You got that right! Next time you fly over a marina, consider almost all of them have AGM batteries down in the bilge on a charger. Oh no!

[dkkim73]

52 minutes ago, GeeBee said:

You got that right! Next time you fly over a marina, consider almost all of them have AGM batteries down in the bilge on a charger. Oh no!

Well, I would guess the charge/discharge profile of a marine battery might be different. I think it might actually be worse in some cases (anchoring overnight). 

But, at least @GeeBee's post explains all the fires I see flying over marinas...

 

[MikeOH]

On an aviation forum, of all places, I'm fascinated that I am being ridiculed for making the lower risk choice.  Enjoy your massive $$$ savings.

[GeeBee]

5 minutes ago, dkkim73 said:

Well, I would guess the charge/discharge profile of a marine battery might be different. I think it might actually be worse in some cases (anchoring overnight). 

But, at least @GeeBee's post explains all the fires I see flying over marinas...

 

Flooded charge discharge profiles are different because many flooded marine batteries were what is known as "Deep Cycle" which has thicker plates that do not warp as readily when taken down low and hit with a bulk charge. AGM batteries because of the nature of their design do not have plate warpage problems and can be taken down lower than any flooded and bulk charged back. They also self discharge slower than flooded. There are so called "deep cycle" AGM's but they are really just have extra mat material. Interestingly the armed services like them because they can have holes blown in the case, easily handling 30 caliber hit, there is no leakage and the battery still functions.

[Shadrach]

43 minutes ago, MikeOH said:

On an aviation forum, of all places, I'm fascinated that I am being ridiculed for making the lower risk choice.  Enjoy your massive $$$ savings.

I’m not ridiculing you in any way.  I’m merely suggesting that decades of operations with few real world issues suggest that it’s likely statistically safer to store your plane with a smart charger on the battery than it is to fly the airplane.

I know of someone that will not leave a battery minder on a vehicle unless he is in the vicinity to monitor and manage any problems. I don’t ridicule him, but I do think that’s overly cautious.

[GeeBee]

My boat has a warning label that leaving it in the water can cause damage. No kidding.

[M20F-1968]

On 5/4/2024 at 3:06 AM, MikeOH said:

Since it's been 3 and a half years since I bought my Concorde RG35AXC, and I don't think it's ever been load tested, I decided to spring for an electronic load: Kunkin KP184 (photo below).

So, this is a PIREP on the Kunkin:  Given the cost was under $200 including tax and shipping the apparent quality is higher than I expected.  While it came with accessories, AC cord, voltage sense BNC-TWP adapter, load wires and lugs...assembly of the load wire to lugs is on you, as is obtaining your own TWP wire (twisted pair).

I topped off the battery with the BatteryMinder and then hooked up the KP184.  The unit went through a quick self test in a few seconds and was already to go in CC (constant current) mode.  Set load current to 33 Amps (Concorde's 1C amp-hour rate for the RG35) and pressed "ON" and started my timer.  Voltage is displayed constantly, as is power, and you can see the voltage 'count down' as the battery depletes.

Exactly 54 minutes later I hit 10.00 Volts (end point voltage for the test per Concorde).  So, 90% capacity (85% is the min).  I feel a lot more confident knowing my battery is still in decent shape.

Time will tell how the KP184 holds up, but for 1/5 of an AMU I'm a pretty happy camper.

 

So I take it that you would recommend the KP184 for capacitance testing of a 12V Concord battery?

John Breda

[MikeOH]

1 hour ago, M20F-1968 said:

So I take it that you would recommend the KP184 for capacitance testing of a 12V Concord battery?

John Breda

Yes, I would. It performed exactly as I had expected.

My only, so far unfounded, reservation is the low cost may imply some degree of low life/reliability; I've only used it once so I have no long term data to report.

[M20F-1968]

Just now, MikeOH said:

Yes, I would. It performed exactly as I had expected.

My only, so far unfounded, reservation is the low cost may imply some degree of low life/reliability; I've only used it once so I have no long term data to report.

I find it interesting that there are about 30 vendors on e-bay, all selling the same unit for $171.57.  Which vendor did you purchase it from.  I assume this is a Made in China product, or something similar.

John Breda

[MikeOH]

3 minutes ago, M20F-1968 said:

I find it interesting that there are about 30 vendors on e-bay, all selling the same unit for $171.57.  Which vendor did you purchase it from.  I assume this is a Made in China product, or something similar.

John Breda

LOL!  Yes, most definitely made in China.  I spent more time than I should figuring out which of the 30 vendors to go with.  Some include shipping, others it's extra. So, make sure to take that into account. I ended up using HUMuu.

[cliffy]

I know of one 172 in a hangar, stored for 2 years, unattended., on some kind of trickle charger that went bad and all the acid (flooded battery)

rolled down the firewall and back through the belly of the airplane. It wasn't a pretty sight. 

Don't know the make of charger so "you all be careful out there" (to quote a very long ago TV program) :-)