Electrical issue after jump start

[busav8or]

The avionics guy that just did my ADS-B install left my master switch on and killed the battery. After jump starting from his truck, the ammeter indicated about a 30 AMP draw with RPM above about 1000 on the ground and the same in flight. After about 30 minutes in the air, the draw went to about 55 AMPS and stayed there! I tried my strobe lights for a second and the ammeter dropped to about 30 again but back to 55 when I turned the strobes off. Shouldn't the ammeter show an increase with a draw like the strobes? I have a 2 year old Gill sealed battery, a Zeftronics R1510L voltage regulator and a 65 AMP alternator. I put the battery on charge after I got home and it seems to holding but I haven't had a chance to fly again since Wednesday when this all happened.

Looking for ideas!

Thanks and Merry Christmas to everyone,
Joe

[Bruce Fenstermacher]

Wouldn't you just like to take it back to him and tell him to return it to you the way you left it with him as far as the battery condition and charging system.

My questions are these. Why would you try to turn something electrical on, increasing the load, in reaction to a high electrical load?

Why when you turned on your strobes the load went down and then back up with the strobes off makes no sense at all.

How did your battery recover after the charge you put in? Perhaps a charged battery will solve the unexplainable gremlins.

[busav8or]

Wouldn't you just like to take it back to him and tell him to return it to you the way you left it with him as far as the battery condition and charging system.

I would and I still might!

Why would you try to turn something electrical on, increasing the load, in reaction to a high electrical load?

Curiosity, I guess! I just did it for a second.

Why when you turned on your strobes the load went down and then back up with the strobes off makes no sense at all.

I agree; thus the post!

How did your battery recover after the charge you put in?

It seems to hold a charge, but I'm going to see what it's like after a few days out of town. (Me, not the battery )

I'm hoping that a good battery charge will solve my problems, too. I'm still scratching my head over the seemingly opposite reaction to the increased load. I'll let you all know what happens in about a week!

[N2625U]

I'm definitely no electrical genius but if the battery was discharged to the point it could not excite the alternator what would be the indications on the amp meter? I'm just remembering when I was a kid with a dead battery in a car that was alternator equipped that after a jump start the alternator would not charge the battery until dad & I put a charge on the battery.

[gfeher]

I can't say that I'm an expert on this, but based on my understanding of what the ammeter shows in our planes and how the battery charges, I think that what Joe saw was normal given the circumstance. So I'll throw this explanation into the ring for consideration.

I think Joe saw two things going on. First, he saw the charge rate increase (the amps increase from 30 to about 55 over the 30 minute period) as the battery heated up. (I bet it was a somewhat gradual rise over the 30 minute period, rather than a sudden one.) Then, he saw the charge rate decrease suddenly (amps decrease from 55 to 30) when he turned on the strobe, and increase suddenly (30 back to 55) when he turned off the strobe, because the alternator was at its limit (charging the battery) and the current to the strobe decreased the charge current to the battery.

My understanding is that the ammeter in our planes essentially shows the current flow to/from the battery. When the needle is pointing on the plus side, it shows current flow into the battery (i.e., a charge current into the battery). When the needle points on the negative side, the alternator (in Joe's case) is not keeping up with the demand (in other words, the current load is too high -- too many things are on) and the battery is being drained at the rate shown on the negative side to help meet the demand. So any time the battery is being charged by the system, you will see the needle deflected to the positive side to show the charge current to the battery. If the battery has been completely drained, like in Joe's case (and assuming a constant voltage charging system like in our planes), you will see a large charge rate (positive needle deflection) at the amperage the battery "accepts" for the charge at that particular instant. What the battery will "accept" for the charge at a particular instant depends on a number of things, one of which is battery temperature. The higher the battery temperature, the higher the charge rate (amps) the battery will "accept" to charge itself. Initially, I think Joe saw the charge rate increase from 30A to about 55A over the 30 min period because the battery was heating up as it was charging (and the engine compartment with the battery was heating up as well) and the battery was gradually "accepting" more charge as it was heating up. But then Joe turned on the strobe, which reduced the amount of current available to charge the battery (to about 30A) because the alternator was at its max output, causing the needle to swing down to + 30A. When Joe turned off the strobe, the full previous current was available to charge the battery and the needle swung back up to + 55A.

I hope that makes sense.

Merry Christmas to you Joe as well.

[canav8]

Wouldn't you just like to take it back to him and tell him to return it to you the way you left it with him as far as the battery condition and charging system.

I would and I still might!

Why would you try to turn something electrical on, increasing the load, in reaction to a high electrical load?

Curiosity, I guess! I just did it for a second.

Why when you turned on your strobes the load went down and then back up with the strobes off makes no sense at all.

I agree; thus the post!

How did your battery recover after the charge you put in?

It seems to hold a charge, but I'm going to see what it's like after a few days out of town. (Me, not the battery )

I'm hoping that a good battery charge will solve my problems, too. I'm still scratching my head over the seemingly opposite reaction to the increased load. I'll let you all know what happens in about a week!

BUSAV8R Do not charge this battery unattended. You may be sorry. It sounds like you may have welded plates in the battery. As a matter of fact, make sure you take the battery out of the plane before you charge it if you havent already.

[busav8or]

Thanks for the replies so far. Gene, I like your explanation of maybe why the ammeter was showing what it was. Doug, I've never heard of welded plates in the battery. What would cause that? Extreme heat from over charging maybe? FWIW, the battery was not particularly warm when I put the airplane back in the hangar after my return flight. Is there some way to test for this condition? Thanks for the warning, though!

Joe

[canav8]

Thanks for the replies so far. Gene, I like your explanation of maybe why the ammeter was showing what it was. Doug, I've never heard of welded plates in the battery. What would cause that? Extreme heat from over charging maybe? FWIW, the battery was not particularly warm when I put the airplane back in the hangar after my return flight. Is there some way to test for this condition? Thanks for the warning, though!

Joe

Joe welded plates is the oxides build up between the plates and short them out. It happens when lead acid batteries sit for a long time or are not kept up to full charge state. It increases the resistance in the battery. distortion occurs and batteries can explode with the increase resistance. smart chargers now have the ability to break down batteries solutions but it takes a lot of time and it is not the perfect solution with a high end charger. I have only seen the evidence of one battery explode in my life but its enough to throw out the caution. A battery short can cause the spike in the amperage also. Although I do not think that jumping a battery will cause these problems. It could like you said with the avionics on though.

[Bruce Fenstermacher]

Lots of things puzzle me.

Why did the load go from 30 to 55 amps with no increase in load? Shorted battery cells? I can't so no to this explanation. I give it 50/50.

Why did the load go down when a load was actually added? Then go back up when the load removed. There is no reasonable explanation I can think of. I'll through out reverse polarity but that is crazy and nothing would be working.

An alternator needs voltage to step it up or charge. If there is no voltage to excite it, it can not produce electricity. This is why some prefer a generator in the bush. A prop start and a method to energize the master relay and your generator is working. An alternator needs power to make power.

[busav8or]

Ok, sulfation I do know about! Could this happen on a less than 2 year old battery that's only been completely discharged this one time and sat dead for a week at the most?

[KS170A]

With a completely dead battery, an external power source was required to start. Presumably, the alternator field was excited prior to disconnecting the external power otherwise, as Bruce mentioned, the alternator could not have output any power. I have the standard generator/ammeter setup in my 170, but assuming your alternator ammeter is set up similarly (i.e. - it's purpose is to indicate the direction of current flow to (positive indication)/from (negative indication) the battery, I offer the following:

Not quite sure what you mean by "30 amp draw." If you mean your ammeter was deflected LEFT (discharge) 30 amps, I think this would clearly be an indication issue as once the external power was disconnected, where would 30 amps be coming from? Not your dead battery, which is where the ammeter is telling you it's coming from.

If you mean the ammeter was deflected RIGHT, then I would expect a dead battery to draw a large current draw for a while. A 30-amp deflection to the positive (right) side sounds reasonable. What does not sound right is turning on the strobes and having the ammeter increase 25 amps. Could be that turning on the strobes was enough short battery cells?

If it were me, I think I'd try a known good battery and see what the ammeter indicates. That would at least confirm or eliminate the battery. Perhaps the solid-state regulator didn't like being jumped to start the airplane at the shop? If connected properly, that shouldn't have been a problem, but you never know.

[Bruce Fenstermacher]

Josh, he said the initial load was 30 amps then went to 55 amps with no interaction on his part. If nothing further happened this would be a mystery. Why would the load have changed. If anything, given no increase in load, as the battery took on a charge, the load would decrease. And a load of 55 amps just to charge a battery is extremely high.

But the story as he told it gets even more weird. He said after the load went to 55 he turned on the strobes, which lowered the load back to 30 and it returned to 55 when he turned of the strobes.

We very likely will never be able to explain this. Hopefully with a good battery, he will never see this behavior again. And we will be relieved of trying to figure it out.

[hilltop170]

Ok, sulfation I do know about! Could this happen on a less than 2 year old battery that's only been completely discharged this one time and sat dead for a week at the most?

If it is a standard Gill battery, 2 years is about all you can expect out of them.

Get a new Absorbed Gas Mat (AGM) battery, that is of course AFTER you determine your charging system is functioning properly. The radio repair shop should be the one to troubleshoot and correct this problem since they had a big hand in causing it.

The Concord RG-25XC or equivalent should last at least 5-8 years. My Concord still shows 12.5v or above after 8 years.

http://www.concordebattery.com/flyer.php?id=36

[GAHorn]

Actually, this makes perfect sense ...if what he means by "draw" is actually a positive-side-of-the-ammeter indication (which we normally refer to as a "charge rate".

When a lead acid battery is constructed, it is made of two types of material: Lead plates and lead-peroxide plates which are separated and submerged in electrolyte, usually made of sulfuric acid (H2SO4).

When the new battery is fully charged the specific gravity of the electrolyte is about 12.7 to 12.9, indicating that it's about 70 percent water and 30% acid. When the battery discharges the peroxide effervesces hydrogen and coalesces sulfur-oxide, the sulfuroxide attaching itself to the battery plates (called sulfation) and the hydrogen excapes to atmosphere... (or in AGM-batteries it is absorbed by the glass mats for re-absorption later). The result is a sulfur coating on the battery plates and a loss of electrolyte specific gravity as it becomes more water and less sulfuric acid.

When the battery is re-charged the electron-migration drive the sulfur back off the plates and into the electrolyte, recreating a more-acidic electrolyte and removing the sulfur from the plates....now ready to provide full current again.

While discharged two things occur: 1) The plates have higher resistance to electrical-flow due to the sulfur on the plates and 2) the "watered-down" electrolyte is less capable of allowing the passage of the electrons. The result is that a fully-discharged battery has high resistance with watered-down electrolyte... therefore it will only allow a reduced flow of electrons (charge-rate is low.) As the battery-plates lose the sulfur they become more acceptant of electrons ...and the sulfur returns to the electrolyte ...recreating an acidic solution, which in itself also is better at allowing the electron flow. RESULT: A fully discharged battery will only begin a re-charge rate that is LOW...and as the battery recovers it will then allow an INCREASED rate of charge. As the battery then becomes fully recharged, the rate will then be reduced artificially by the REGULATOR, to provide a "finish" charge.

That's when everything works as designed. So when Joe "jumped" his airplane...(hopefully with the battery-Master ON)... then the alternator field was also powered, and when the engine started and the jumper cables removed the excited alternator went to work attempting to re-charge a battery with high-resistance ...so it only showed about 30 Amp charge rate even tho' his alternator was trying to send the full 55/65 it was capable of to the battery. As the battery regained it's health it began to accept a higher charge-rate and the ammeter reflected that showing 55 Amps. Then he added an electrical LOAD ...the strobes... and the alternator could not produce any MORE power than it's full amount so the electricity being used to power the strobes was subtracted from the charge-rate indicated on the ammeter...thereby reducing the indication down to 30 again. As the strobes were then turned OFF....the alternator was able to send the full 55 Amps to the battery again...and the ammeter showed that.

NOW THE PROBLEM IS that the battery likely suffered a bit of damage due to the deep discharge and will have a shortened life as the result. But Richard is correct, some folks only experience a 2-year life with ordinary flooded cell batteries.... while others, who have properly-calibrated voltage regulators and do not ever allow their batteries to be harmed by frequent/full discharges.... will experience many years of service from their ordinary flooded cell batteries.

Some folks, rather than spend time and money maintaining a system they and their mechanics do not understand.... will simply opt-out for an AGM or "gell cell" battery .... and some will even spend hundred$ on exotic batteries rather than attempt to understand and maintain what are actually very simple systems.... once they are understood and maintained.

At any rate, I hope this explanation helps.

George

[busav8or]

Thanks again to all the responses! Finally got back on the ground to read the thread! The ammeter was, indeed, showing a positive deflection of 30-55 amps during the flight. Sorry if my term "draw" caused confusion. I can see where it might. I did "jump" the airplane (maybe should have said used a Chevrolet 2500 external start unit! ) with the master switch on, and the ammeter showed an immediate positive indication.

So far, since returning home from the avionics shop, I have been able to charge the battery to what appears to be a full charge. Sometime next week I should be able to check if the charge remains after sitting for a while and go from there on deciding how to proceed. I'll post more when I know more!

Thanks again,
Joe