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Hot battery
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Paul, which inverter did you lower to 1 amp, #1 or #2? Or does it matter?
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Tom, switching my transfer switch to “shore” or “generator” bypasses the inverters completely. It is nice option if an inverter fails.
Jerry, I set inverter #1 to charge at 1 amp and inverter #2 to charge at 15 amps. On my coach, inverter #1 was the dominant charger. This created too high a load on one leg which caused breakers to trip. By forcing inverter #2 to be the primary charger, the loads are more evenly balanced. I am on day 4 at a resort in SW Florida with all 4 A/C units running in addition to other normal loads and have not tripped a breaker yet.
This my first trip where I haven’t tripped a breaker at some point so I am thrilled.
Paul
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As it turns out my inverters were overcharging battery, Nelson advised to disconnect Temp Comp sensor, did that and all good. Battery temps back to Normal ( within 20 degrees of ambient )
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Granvil,
I’m glad that worked for you, although it makes no sense when your batteries are each individually connected to a buss bar. It suggests that the single hot battery has a less resistive charging path than all other batteries in the bank. It also suggests the temperature sensor was attached to a cold battery. Even then, something else seems wrong. At 70 degrees the float charge voltage should be about 13.3V and this is typically the default when the temperature sensor is removed. The highest float charging volatge should be about 13.7V at 30 degrees. Even if you are in the artic circle enjoying freezing temperatures, 13.7V should not be high enough to cause the batteries to get hot.
If it was overcharging, then the charger would not have been in float charge mode. This is why it’s important for everyone to occassionally look at what charge state your charger is in. If it doesn’t go to float in the expected time frame or bounces in an out float, you need to look into why. As Granvil discovered, when the charger and batteries aren’t working in harmony they don’t always tell you so through an alarm.
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Paul, thanks, I’m going to try your suggestion and change one to 1 amp charge.
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Granvil,
I strongly advise against disconnecting temperature sensors and leaving them disconnected. The problem needs to be addressed for longevity of your house batteries. Check Menu 21 and find out if one has failed “low” or is open-circuit. To do so, put both inverters in menu 21 (go to menu 8, then hit red + green buttons at the EXACT same time, then scroll to the end of the setup menu (#20), then hit the red + green button again at EXACTLY the same time, you get the tech menus, #21 is temperatures. Using menu items down (far left button), scroll to battery temp counts. This is no the actual temperature, but a number between 0 and 255 that represents the temperature for the microprocessor. Do this and either give me a call or report back on here. An “open circuit” reading on one of the temp sensors would read 255. The actual number this time of year is usually between 100 and 115. If one reads 255, you might as well disconnect the other so the two inverters won’t be in charging value conflict, but it is NOT WISE to leave them disconnected. In hot climates, batteries WILL get overcharged if the inverters think it is only 70-degrees outside (which is what the inverter assumes if the temp sensors are not connected).
Hope this helps.
Ben Cummings
Parliament Motor Coach -
thanks Ben, I’m back in Fla and coach is in NC so the ambient temp is probably pretty close to 70. I will be back up there in a week or so and will do as you advise. Thanks for the advice,
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The only time I have evere heard of a sulphur smell with AGM or gel batteries is if the case popped or the relief valve let go, both conditions are a failed battery.
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So, if I load test it will that tell me whether it failed ?
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I am not sure if or how long a sealed battery that has vented to atmosphere will perform or if it will pass a load test.
I do know they are sealed and if you get the sulphur smell the case has cracked or the relief valve has opened. Someone that understands the technology might be able to explain if such a battery is useable, even if it passes a load test.
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Ben,
On the subject of Trace BTS sensors. When I look at page 21, the value that gets reported through the sensor seems to be inverse to the temp. Meaning the hotter the batteries get the lower this number is, and the colder they get the higher this number gets. When I look at the temp compensated battery voltage, when they batteries are hot the temp comp voltage is higher then the actual. So it would seem they are working right, just seems strange that they are inverse to the actual temp range.
I believe when my batteries are at 105-110 degrees or so, the 21 page shows around 55. I will have to check it again this weeked.
Can you confirm that to be correct?
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Michael,
Yes, you are correct. The Counts of 255 = 70 degrees, and the counts number goes down at the battery & ambient temperature go up. Sounds like you are seeing normal operation.
Ben @ Parliament Motor Coach
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Once one of the relief valves opens, the battery internal pressure will no longer be able to be maintained at the 4psia that is needed to keep/force the gases back in solution (the electrolyte), so the battery IS in effect a boat anchor after that happens. The physics of battery charging is that EVERY battery will produce hydrogen gas at the maximum voltage to completely be recharge, known as Total Gas Voltage (TGV). In an AMG battery, where the electrolyte is wicked up in a fiberglass matt, gassing is detrimental. So the design was to put the battery under pressure (around 4psi atmospheric) to keep the gasses in the electrolitic solution, much like a pressurized cooling system of your car keeps the coolant from boiling. Unlike a regular liquid lead acid battery, which has vent caps on top, the round “cap-like” items on an AGM or Gel battery are actually pressure relief valves. Once they open, to prevent the case from blowing out and/or splitting in the event of a failure, that is pretty much it for the battery. They will not truly reseal, and at that point the battery is at atmospheric pressure, so the battery will continue to gas when charged until there is no electrolyte left to complete the chemical exchange between positive and negative plates.
Hope that helps.
Ben Cummings
Parliament Motor Coach -
Ben,
Great explanation!
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I have been following the battery temp issue and just went out to the bus to check the sensor values, now that I know how to get into that menu…(g).
Menu 21 shows Battery temp on one inverter to be 00 and the other at 126. Ambient temp about 72 in the garage. No big loads going through inverters, all a/c shut down. Only housekeeping loads when I checked this. I went to the inverters and unplugged the sensor cable and got 255 at the one that was reading 00, so I assume the sensor is bad?
I also have my sensors on two different batteries, mounted on the sides as they should be, but not on the same battery.
Both seem to be the same temp when you touch them. I did not have my ir temp gun handy to check, but will do that in the future.
So, what does the brain trust think? Do I need a new sensor, and should I relocate them to the same battery when I get one?
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