Turn off the charger immediately you are killing those cells!Also….here is the current status of my BMS….idk if it helps or not…
As @Supervstech allready mentioned we need to know the locked rotor amp rating on the freezer?but I recently upgraded my freezer to an 18.5 cu. ft.
Can you start the freezer later in the day when the sun is higher in the sky? I assume that freezer is full and any left over space is filled with bottles of water or liquid sodium. I'm curious if you have done an analysis to determine state of charge of cells when the inverter powers up in the morning. What are you using for charge controller? Do you know for sure that charger is filling up cells during the day? I would think cells would be quite a bit above 25v for full charge.Hi all,
I have a fairly small system, running 8 3.2V LifePo4 280amp hour batteries. I’m only running a few lights a refrigerator and a freezer. Everything has been working great, but I recently upgraded my freezer to an 18.5 cu. ft. My inverter is 3000 watt. I have the freezer on a timer to shut off at night and save batteries. But in the morning when it try’s to kick on the inverter alarms.
Is it possible that I have an inverter with enough watts butt the surge is to much for it on the start up?
We havfilling ue one string of 3 of 280w panels, they reach around 25 volts, showing 100% on the charge controller soon after the sun is up. No issues running things as long as there is sun. But the startup in the morning of the freezer on the timer is when we have the issue.
When I bough the cells they were brand new and already balanced. I checked each one individually and they were all 3.3
- Did you top balance your battery per the guide before you deployed it?
- How long has it been in service.
I am completely off grid….this is my ONLY source of power….can you please help me figure out how to fix it?@ShaneT
Given that you have been operating your battery without a BMS (the black cable bypasses it and makes it as though the BMS isn't even present), there is a very real possibility that you have damaged your cells.
You have just shown that your BMS is desperately trying to protect the battery.
Recommend you do as @smoothJoey says and then REMOVE all charge sources from the system until you get this figured out.
When I bough the cells they were brand new and already balanced.
I checked each one individually and they were all 3.3
This set up has been in service now for a couple months. The change with the freezer has been about 2 weeks.
Unplug the fridge while the freezer starts. If your lucky the fridge will start while the freezer's running. Then all you'll need is another timer insuring the fridge is off while the freezer starts.
Okay, I have everything turned off. No charging sources. So I need to remove haha big black wire all together?Dude. Catch up. He's bypassed his BMS and is running cells as high as 3.9V. The fridge/freezer is no longer on the radar.
Okay, I have everything turned off. No charging sources. So I need to remove haha big black wire all together?
The (blue) BMS wires should be the only ones going to the negative terminal? Then the black wires from the BMS go up to the negative busbar?
So nice of you to help. I was thinking one of those Heltec active balancers could help him in the short run but that stuff takes a while to get.Shane and I spent about an hour on the phone. Many of the battery terminal and bus bar connections needed to be tightened. Proper torqueing still needs to occur, but at least things are good and "snug." Given the sheer number of connections that were tightened, I suspect that will address the issue with the freezer.
Charge controller has been set to a 27.6/27.2V absorp/float to lessen the impact of cell imbalance and hopefully lengthen the period where cells can balance. He's likely going to get lots of BMS OVP triggers, but hopefully over time, the cell delta will lessen.
Also have a plan to have him use resistors to bleed down individual cells if the BMS can't eventually bring things in line.