So let me put this is all in context for everyone. There are several points in the batteries charge and discharge at which you will find resistance.
The only measurable internal resistance is the constructed internal resistance (CIR).
This you can measure with an analyzer. Generally the smaller the battery the higher resistance. Big batteries 100 amp hour or better usually have 0.1-3 milliohms where as a 4 amp hour battery can be as high as 12 milliohms.
This resistance is based on the capacity of the battery and often poor construction or formating causes a higher than usual resistance. So running things like cap dumpers, inductor dumpers, high frequency spike ect.. Can often lower this resistance by raising the capacity. Really all your doing is adding formatted space to the plates that otherwise wasn't utilized at the factory, or your clearing up damaged areas.
So the second resistance which I said earlier is dynamic. It shows up when your running loads. Under normal condition if you discharge a battery through a load you can calculate the ohmic loss across the load versus the current and then calculate the CIR and usually be pretty close to what your running. Until the battery gets way below nominal voltage (IE 10v - 11v or below) then you start to see a change in the current that can only be explained by internal resistance in the battery. I do not know what causes the low side event other than capacity at play. Never spent to much time worrying about this as I do not discharge that deep, but it happens and it measurable.
So on the other end of the spectrum you see a similar event. A measurable event. As a battery charges up (Conventionally) it sinks so much current into the plates and so much into heat from either the reaction or the CIR. But as the voltages get really high it will slows the current even more. Again you can measure this. At this point you are only making heat, and as the heat builds up so does the resistance. Now no matter what the potential is going into the battery you will see an Ohmic loss and your current will be reduced further than what the math tells should be happening. So you have to at that point blame the battery and assume heat is the issue.
So now we have to look at both event at the same time because of our Hybrid setup. And let me set that straight too while I am at it.
For any of these 3 battery setups we are making a mistake in the presumption that you are running a 24 volt serial bank down into a 12 volt bank for potential difference of the 2 banks. More Bull$hit from that thought alone than any other around this system. .... We are wiring a Hybrid Serial Parallel bank. This is ONE Battery. You always measure a battery or power source from Low to High and in this case we do not have a ground to measure. Period, no possible argument unless your goofy.
By setting it up this way we have the ability to control, at will, the position of the plates and the action we want those plates to perform. The entire thing could be in case an still work the same way.
Ok off my rant...Back to the case at hand. Like I said we have to consider both sides now. We have discharged batteries on top and charged batteries on the bottom. Do to both cases it becomes a real easy to measure event. If the load is 1 ohm our voltage on the battery should equal to our current. But adding an ammeter after the load will indicate a difference. Maybe you have 8 volt of potential but you only 7.9 amp of current. How is it even possible when Ohms law dictates that, that is not possible. I don't know I avoid the situation entirely but if you look for it you'll see it.
Maybe if your batteries are 10's of amp hours and your load is millamps up to a couple amps it gets hard see. But you go to push 100's amps you see it clearly. Its an anomaly, and I do not think its unique to this system. In engineering they look for heat loss in all batteries but that is a little more straight forward because of the ability to use a ground.
There are other anomalies too. Tinman from OU.com has video on youtube measuring an inverter under normal condition at about 60% efficient. Where as on the on the 3 battery setup the inverter is 80% roughly. And I could go on but this post is long already.
So back to the point I was stressing to Desa. Move the power, keep the batteries at their most efficient point without burning the power off. Thats the best and easiest thing to do. Don't allow the batteries or the system to eat power anymore than they have to, to function.
Now you know everything I know. It may not sound right its just what I have seen.
Matt
The only measurable internal resistance is the constructed internal resistance (CIR).
This you can measure with an analyzer. Generally the smaller the battery the higher resistance. Big batteries 100 amp hour or better usually have 0.1-3 milliohms where as a 4 amp hour battery can be as high as 12 milliohms.
This resistance is based on the capacity of the battery and often poor construction or formating causes a higher than usual resistance. So running things like cap dumpers, inductor dumpers, high frequency spike ect.. Can often lower this resistance by raising the capacity. Really all your doing is adding formatted space to the plates that otherwise wasn't utilized at the factory, or your clearing up damaged areas.
So the second resistance which I said earlier is dynamic. It shows up when your running loads. Under normal condition if you discharge a battery through a load you can calculate the ohmic loss across the load versus the current and then calculate the CIR and usually be pretty close to what your running. Until the battery gets way below nominal voltage (IE 10v - 11v or below) then you start to see a change in the current that can only be explained by internal resistance in the battery. I do not know what causes the low side event other than capacity at play. Never spent to much time worrying about this as I do not discharge that deep, but it happens and it measurable.
So on the other end of the spectrum you see a similar event. A measurable event. As a battery charges up (Conventionally) it sinks so much current into the plates and so much into heat from either the reaction or the CIR. But as the voltages get really high it will slows the current even more. Again you can measure this. At this point you are only making heat, and as the heat builds up so does the resistance. Now no matter what the potential is going into the battery you will see an Ohmic loss and your current will be reduced further than what the math tells should be happening. So you have to at that point blame the battery and assume heat is the issue.
So now we have to look at both event at the same time because of our Hybrid setup. And let me set that straight too while I am at it.
For any of these 3 battery setups we are making a mistake in the presumption that you are running a 24 volt serial bank down into a 12 volt bank for potential difference of the 2 banks. More Bull$hit from that thought alone than any other around this system. .... We are wiring a Hybrid Serial Parallel bank. This is ONE Battery. You always measure a battery or power source from Low to High and in this case we do not have a ground to measure. Period, no possible argument unless your goofy.
By setting it up this way we have the ability to control, at will, the position of the plates and the action we want those plates to perform. The entire thing could be in case an still work the same way.
Ok off my rant...Back to the case at hand. Like I said we have to consider both sides now. We have discharged batteries on top and charged batteries on the bottom. Do to both cases it becomes a real easy to measure event. If the load is 1 ohm our voltage on the battery should equal to our current. But adding an ammeter after the load will indicate a difference. Maybe you have 8 volt of potential but you only 7.9 amp of current. How is it even possible when Ohms law dictates that, that is not possible. I don't know I avoid the situation entirely but if you look for it you'll see it.
Maybe if your batteries are 10's of amp hours and your load is millamps up to a couple amps it gets hard see. But you go to push 100's amps you see it clearly. Its an anomaly, and I do not think its unique to this system. In engineering they look for heat loss in all batteries but that is a little more straight forward because of the ability to use a ground.
There are other anomalies too. Tinman from OU.com has video on youtube measuring an inverter under normal condition at about 60% efficient. Where as on the on the 3 battery setup the inverter is 80% roughly. And I could go on but this post is long already.
So back to the point I was stressing to Desa. Move the power, keep the batteries at their most efficient point without burning the power off. Thats the best and easiest thing to do. Don't allow the batteries or the system to eat power anymore than they have to, to function.
Now you know everything I know. It may not sound right its just what I have seen.
Matt
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