astrnmrtom
New Member
- Joined
- Nov 21, 2022
- Messages
- 9
I have a real head scratcher starting back in Sept when I changed out my 4 failing 6v agms for 4, 100ah 12v lifepo4 batteries.
My system:
900 watts of solar - 3 pairs of 150 watt panels, each pair wired in series, then connected in parallel, feeding an epever Tracer 4210an, mppt charger with an MT-50 remote.
Go Power IC3000 psw inverter/charger with remote panel.
Renogy battery monitor with shunt, and a drok wireless monitor with hall effect sensor.
4, 100ah self heating Amperetime lifepo4 batteries wired in parallel.
The problem:
Starting in the am and continuing throughout the day, the inverter will randomly shut down, as if someone pushed the off switch. No warning, no errors, it just goes off. It can be immediately restarted and will run fine for a while before going off again. Batteries in the am are at 70% capacity according to both meters. I've even had a shutdown with batteries @97%. The bizarre thing is, this NEVER happens at night. It runs all night long without a hiccup, even when running more things, and after going to bed where the only appreciable load is the refer.
Loads: Main daytime load is a Fisher and Paykell residential refrigerator. Average draw from the batteries around 16amps. Occasional load is the water pump which draws about 8amps.
The history: After a bunch of troubleshooting and checking and cleaning every connection, I suspected the inverter. It important to note that when this started, I was using a different inverter with separate charger. I suspected a bad internal connection in the inverter because failures seemed to be happening as we drove down the road. Seemed to happen more on bumpy roads so I replaced that inverter with the ic3000. Tried the wiggle test on all cables and connections to no effect.
The batteries are wired correctly with new equal length cables, with the main positive and negative at opposite ends of the pack. All batteries were installed per instructions. Along with the batteries I purchased a dedicated lifepo4 charger from Amperetime. This was done for use with my small portable generator because the original, and new inverter/chargers draw too many amps for the small generator. As per the instructions, I charged each individual battery with the dedicated charger before connecting in series so they were all balanced. I've sat by the remotes to see if I could catch any anomaly prior to shutdown. I haven't been able to catch it in the act of shutting off, but I have looked at all the meters within a second or two of the shutdown and everything reads normal. Checking the inverter readout after restarting everything is normal, no errors codes. Even checked the inverter temperature readouts and they are in range. Except for the initial charge, all charging has been done with built in chargers while plugged into campground power. Batteries seem to accept the charge just fine. It's only when we unplug, that the solar takes over charging.
Although never say never. I cannot believe all four batteries are bad because they work fine all night long. I can even turn on my coffeepot which will draw 90 amps @12v and they handle it just fine.
Again, this only happens during the day. It may happen when a small load switches on because every once in a while when the water pump first cycles, the inverter drops out, but not every time. Because of this, I wonder if the other times it isn't when the refrigerator compressor starts up, but again not every time because I can tell when it's running by looking at the battery monitor.
Because it only happens when the sun is shining, I'm wondering if some how it's related to the solar charger. Is there some very fast transient spike that has the battery bms shut off? I never see any odd voltages on any of the meters. I've even had my wife cycle the water pump and watched the meters. Volts and amps change as expected with neither out of the ordinary. I've confirmed all the charger and inverter settings a million times.
(Yesterday afternoon) Just had another shutdown and this time I was watching the battery meter when it happened. Everything went dead, even the 12v side, which came back to life 2 or 3 seconds later. So, that tells me the bms didn't like something, and shut the batteries down. Only thing I can imagine is a transient spike in voltage too fast for the meters to register before the bms shuts off the power. Since this only happens during the day, I suspect something is going on with the solar controller. This may have been happening for an undetermined time going back prior to switching to lifepo4, except back then, lead acid batteries don't have a bms and an occasional spike in DC voltage would have no effect. It's also odd that with 4 batteries in parallel that the whole system could shut down over a transient voltage anomaly unless it becomes a cascading shutdown.
Solar controller has three factory settings, flooded, sealed, and gel, with a fourth user setting. In the user setting I can set all the recommended levels. I initially used the user setting, but have tried the others with the same results.
So, for the last hour of sun yesterday, I shut off my solar to see if I get another failure. Next step will be to disconnect a pair of panels because I am over panelled even though I've never seen the max our of my controller.
Sun is down now and no more failures since disconnecting the panels. Hummm.
More history: Between Sept and now, most failures were happening while going down the road from campground to campground. These were campsites with utilities. We've always run off the inverter going down the road. That's why I originally thought it was vibration induced. This is only the second time boondocking. Couldn't troubleshoot while driving down the road. We'll be boondocking for the next two weeks so this is the first time I've really been able to closely watch the system. All connections have been checked and checked again. Everything is clean and tight. Happens when sitting still.
Latest step. Let the system run off the inverter from an hour before sunset last night, till 9am this morning with the panels disconnected. Ran fine the whole time. At 9:am I started the generator and the batteries accepted a charge. I shut the generator off @70% soc, climbed up on the roof and unplugged a pair of panels. The remaining panels are only slightly over the controller rating - 600 watts. Reconnected the system. It charged for an hour at 21amps before it failed again. Exact same symptoms.
Batteries are in an open compartment on the shaded side of the motorhome with ambient temps in the upper 60s.
I've disconnected my panels again, and am completing the charge with the generator. Batteries seem to be accepting the charge just fine.
It appears there's something going on when charging by solar that the battery bms doesn't like. I'm stumped.
My system:
900 watts of solar - 3 pairs of 150 watt panels, each pair wired in series, then connected in parallel, feeding an epever Tracer 4210an, mppt charger with an MT-50 remote.
Go Power IC3000 psw inverter/charger with remote panel.
Renogy battery monitor with shunt, and a drok wireless monitor with hall effect sensor.
4, 100ah self heating Amperetime lifepo4 batteries wired in parallel.
The problem:
Starting in the am and continuing throughout the day, the inverter will randomly shut down, as if someone pushed the off switch. No warning, no errors, it just goes off. It can be immediately restarted and will run fine for a while before going off again. Batteries in the am are at 70% capacity according to both meters. I've even had a shutdown with batteries @97%. The bizarre thing is, this NEVER happens at night. It runs all night long without a hiccup, even when running more things, and after going to bed where the only appreciable load is the refer.
Loads: Main daytime load is a Fisher and Paykell residential refrigerator. Average draw from the batteries around 16amps. Occasional load is the water pump which draws about 8amps.
The history: After a bunch of troubleshooting and checking and cleaning every connection, I suspected the inverter. It important to note that when this started, I was using a different inverter with separate charger. I suspected a bad internal connection in the inverter because failures seemed to be happening as we drove down the road. Seemed to happen more on bumpy roads so I replaced that inverter with the ic3000. Tried the wiggle test on all cables and connections to no effect.
The batteries are wired correctly with new equal length cables, with the main positive and negative at opposite ends of the pack. All batteries were installed per instructions. Along with the batteries I purchased a dedicated lifepo4 charger from Amperetime. This was done for use with my small portable generator because the original, and new inverter/chargers draw too many amps for the small generator. As per the instructions, I charged each individual battery with the dedicated charger before connecting in series so they were all balanced. I've sat by the remotes to see if I could catch any anomaly prior to shutdown. I haven't been able to catch it in the act of shutting off, but I have looked at all the meters within a second or two of the shutdown and everything reads normal. Checking the inverter readout after restarting everything is normal, no errors codes. Even checked the inverter temperature readouts and they are in range. Except for the initial charge, all charging has been done with built in chargers while plugged into campground power. Batteries seem to accept the charge just fine. It's only when we unplug, that the solar takes over charging.
Although never say never. I cannot believe all four batteries are bad because they work fine all night long. I can even turn on my coffeepot which will draw 90 amps @12v and they handle it just fine.
Again, this only happens during the day. It may happen when a small load switches on because every once in a while when the water pump first cycles, the inverter drops out, but not every time. Because of this, I wonder if the other times it isn't when the refrigerator compressor starts up, but again not every time because I can tell when it's running by looking at the battery monitor.
Because it only happens when the sun is shining, I'm wondering if some how it's related to the solar charger. Is there some very fast transient spike that has the battery bms shut off? I never see any odd voltages on any of the meters. I've even had my wife cycle the water pump and watched the meters. Volts and amps change as expected with neither out of the ordinary. I've confirmed all the charger and inverter settings a million times.
(Yesterday afternoon) Just had another shutdown and this time I was watching the battery meter when it happened. Everything went dead, even the 12v side, which came back to life 2 or 3 seconds later. So, that tells me the bms didn't like something, and shut the batteries down. Only thing I can imagine is a transient spike in voltage too fast for the meters to register before the bms shuts off the power. Since this only happens during the day, I suspect something is going on with the solar controller. This may have been happening for an undetermined time going back prior to switching to lifepo4, except back then, lead acid batteries don't have a bms and an occasional spike in DC voltage would have no effect. It's also odd that with 4 batteries in parallel that the whole system could shut down over a transient voltage anomaly unless it becomes a cascading shutdown.
Solar controller has three factory settings, flooded, sealed, and gel, with a fourth user setting. In the user setting I can set all the recommended levels. I initially used the user setting, but have tried the others with the same results.
So, for the last hour of sun yesterday, I shut off my solar to see if I get another failure. Next step will be to disconnect a pair of panels because I am over panelled even though I've never seen the max our of my controller.
Sun is down now and no more failures since disconnecting the panels. Hummm.
More history: Between Sept and now, most failures were happening while going down the road from campground to campground. These were campsites with utilities. We've always run off the inverter going down the road. That's why I originally thought it was vibration induced. This is only the second time boondocking. Couldn't troubleshoot while driving down the road. We'll be boondocking for the next two weeks so this is the first time I've really been able to closely watch the system. All connections have been checked and checked again. Everything is clean and tight. Happens when sitting still.
Latest step. Let the system run off the inverter from an hour before sunset last night, till 9am this morning with the panels disconnected. Ran fine the whole time. At 9:am I started the generator and the batteries accepted a charge. I shut the generator off @70% soc, climbed up on the roof and unplugged a pair of panels. The remaining panels are only slightly over the controller rating - 600 watts. Reconnected the system. It charged for an hour at 21amps before it failed again. Exact same symptoms.
Batteries are in an open compartment on the shaded side of the motorhome with ambient temps in the upper 60s.
I've disconnected my panels again, and am completing the charge with the generator. Batteries seem to be accepting the charge just fine.
It appears there's something going on when charging by solar that the battery bms doesn't like. I'm stumped.
