New 24V 200AH LiFePower4 - Current Overload

[jeremyee]

I have been running 4x AGM 12 volt 100 amp battery's for about 3 months with a Victron 1200 watt inverter with no issues. A couple days ago I switched to a 24 LifePower rack style battery and every night the battery has shut off going into an alarm. Tonight I was monitoring the BMS and the alarm was for over current. I am running my fridge an a couple of computers (shut off at night) and garden lights off the system. After the new LifePower Battery shut down I flipped the breaker and switched on the old AGM batterys and saw the inverter pull up to 50 amps for a few seconds and then drop back down to 4 amps.

I am new to the EG4 battery and am wondering if I have a faulty BMS or do I need a 2nd 24V 200a EG4 Battery due to the Power surge from the Fridge. Below is a graph from VIctron of the voltage & amp usage. Left of the line is the AGM battery's and to teh right is the EG4 Battery. Th black circle is where the event occurred. The left black circle should be over too the right where the amp drop is just next to the other black circle.

 

[BentleyJ]

I'm not specifically familiar with the EG4 battery but I've sure looked at lot of data. Here is my observation. According to their specifications the 24V, 200Ah model has a 100A BMS and there is nothing in the chart you posted to suggest the current draw ever exceeded even half that value. Is there a set up menu or DIP switches on the battery where the user can specify a custom over current protection value? Maybe yours is just set too low. Some BMS models even have a separate charge and discharge value that can be set by the user for their specific application. Otherwise the voltage on the EG4 looks very stable and exhibits the characteristic lower voltage drop while discharging compared to AGM.

 

[jeremyee]

Thank for the reply. Looks like the only to change the settings is via RS485 com to the BMS and it's password protected. I will try to get the settings later tonight. I think I am figuring out what is causing it and now to figure out why. I do have a 24 V Dc to 12V D/C Isolating transformer to run my Garden lights. I shut off the breaker to the 24V to 12V transformer and the BMS did not go into over current alarm all day or night. I am going connect the 120V A/C to 12V A/C transformer to the Inverter and feed the lights off that rather than the 12V D/C plant. All the lights are LED's and rated for A/C or D/C. Maybe I am getting some sort of surge from the lights. At least I will know if connecting the garden lights back up and it happens again where to focus my troubleshooting. I am hoping the caps in the inverter can handle the surge that seems to be causing this from the garden lights.

 

[BentleyJ]

You mentioned a 24V to 12V DCDC Isolating transformer. I'm not familiar with this terminology, it seems to be a bit of an "oxymoron" in the sense that a transformer only works with AC. Most DC DC converters are either Buck or Boost type converters that use high frequency PWM along with inductors and capacitors to raise or lower the DC voltage directly, without the use of an actual transformer. My understanding anyway.
Interestingly, I had a similar problem as you with a Schneider PWM charge controller attached to a 48V battery. Somehow it was producing high voltage transient spikes that the BMS interpreted as cell OVER voltage and would rapidly turn the contactor off and on. Also, LED's can be a really big source of electrical "noise" due to their switching power regulators. We have an Insteon home automation system that uses Power Line Modulation to communicate between devices. Certain types of LED's, especially the really cheap generic ones, produce so much high frequency pollution that the automation system fails completely.
It sounds like your are right on target with your troubleshooting. I suspect there will be NO problem with running the AC transformer directly off the Inverter.
If you do wish to go back to the DC DC converter perhaps you could try something like a TDK line filter, RSEV-2020. I'm using something similar inside a combiner box for a 3.0 KW Enphase microinverter system. The line filter prevents the Enphase power line modulation signal to the Envoy from polluting the rest of the electrical system and the aforementioned Insteon Automation System.
Let me know how it goes.

 

[jeremyee]

Not aware transformers are an A/C device only but could be wrong. To state the device as per the vendor it's a 24V to 12V DC to DC Isolating converter.

Going to try the power the garden lights via transformer for now until i get another battery. Even know I am only running a couple small circuits in the house, loosing power becomes irritating.

Interesting on the noise issue as I do run a UPB network on all my switches in the house. Once I start rolling over more of the circuits I am sure I will encounter some issues. lol

Thanks for all the advice

 

[Tony Moser]

Having the same problem, no fix yet waiting for a communication cable from Signature Solar. Back to my old
agm's until I can figure this out. Any updates? on your system.

 

[jeremyee]

Having the same problem, no fix yet waiting for a communication cable from Signature Solar. Back to my old
agm's until I can figure this out. Any updates? on your system.

I talked to the vendor and the only thing we could think of is a bad BMS but the only to prove it is to send the BMS back for testing. I just leave a pair of AGM batterys connected at night for now and that prevents the EG battery from going into over current protection. Going to buy for more battery's in a few weeks so I don't completely kill the amg battery.

It seems to me like a surge from the inverter when at 300 watts is being pulled and the fridge compressor starts up. The best I can tell is it hits a 20 amp surge for less than a second and that's what triggers the BMS to go into a over current protection mode.

I hope this is not a hardware problem since I will be buying 4 more (1x 24volt and 3x 48volt) battery's and also upgrading to a 3kw inverter.

Adding my batt data from the BMS

 

[jberger]

Is there anything in the HistoricalData tab that correlates with the Victron logging?
I am just going to assume that the victron log is smoothed out, given the time axis, and that's not allowing the real spikes to show up. Just wondering what you could see in the BMS logs and if there was a way to increase the log sampling rate to look for it.

 

[jeremyee]

Is there anything in the HistoricalData tab that correlates with the Victron logging?
I am just going to assume that the victron log is smoothed out, given the time axis, and that's not allowing the real spikes to show up. Just wondering what you could see in the BMS logs and if there was a way to increase the log sampling rate to look for it.

I don't have the password to access the history tab but you can log the data via PC. The BMS app shows -25 amps just before the disconnect. below is a capture of the csv export.

 

[Zachrey]

I am running into a similar problem with EG4 24V, 200AH battery that keeps shutting off from even the inrush current when you plug in a laptop charger. But the main problem is turning off at night the Outback VFX3524 inverter-charger and in the morning, when you turn the inverter back on, the battery immediately shuts off and STAYS off (which I think suggests "short circuit" protection mode). The ONLY way to bring the system back up is to shut off the PV and battery breakers for the Outback FM80 charge controller and the VFX3524 inverter and THEN cycle the power on the battery with the white circuit breaker and THEN, using a long skinny wire, bypass the circuit breaker that connects the battery to the FM80 controller and THEN flipping on the circuit breaker to the FM80. The long skinny wire apparently "pre-charges" the capacitor in the FM80 controller so the battery doesn't freak out when you flip on the breaker. After the controller is back up, turn on the PV and make sure you get at least a couple hundred watts coming in. Now you bypass the 250 Amp inverter breaker with the long skinny wire to pre-charge the capacitor inthe VFX3524 inverter and THEN flip up the 250Amp breaker. LORD willing, it should come up without killing the battery. But the ONLY bugaboo, so far, is if you plug in the laptop charger at the peak of the 60Hz sinewave and you get the audible snap from the outlet. That also will make the battery shut down.

When I used the software to check the battery, it said that the parameter for "SHORT CIRCUIT" is 500us (500 microseconds). so it appears that if you pull more than 250Amps for more than 500us, then it shuts down and STAYS down. If I could change that parameter to, say 1,000us or 5,000us, that might make the BMS calm down and not freak out from inrush currents from capacitive loads like the FM80, the VFX3524 and laptop power supplies. The toaster works just fine pulling about 50 Amps from the battery but it is neither a strongly inductive or capacitive load.

Does anyone know what the password for the software is?!

 

[Zachrey]

Here is a video demonstrating he problem.

The "solution" is to use the "long skinny wire" to bypass the breakers to limit the inrush current so you can turn stuff back on again.

 

[Tony Moser]

I have been running 4x AGM 12 volt 100 amp battery's for about 3 months with a Victron 1200 watt inverter with no issues. A couple days ago I switched to a 24 LifePower rack style battery and every night the battery has shut off going into an alarm. Tonight I was monitoring the BMS and the alarm was for over current. I am running my fridge an a couple of computers (shut off at night) and garden lights off the system. After the new LifePower Battery shut down I flipped the breaker and switched on the old AGM batterys and saw the inverter pull up to 50 amps for a few seconds and then drop back down to 4 amps.

I am new to the EG4 battery and am wondering if I have a faulty BMS or do I need a 2nd 24V 200a EG4 Battery due to the Power surge from the Fridge. Below is a graph from VIctron of the voltage & amp usage. Left of the line is the AGM battery's and to teh right is the EG4 Battery. Th black circle is where the event occurred. The left black circle should be over too the right where the amp drop is just next to the other black circle.

View attachment 79887

I've been working with the vendor for hours with this problem. Completely talking down my system and rebuilding it. My problem is a little similar, I have 2 3k 24v growatt's in split phase, when I have an in rush of 12 amps or more my battery shuts down. But when I set it up in parallel it's fine. This system has been running fine for 9 months with AGM's. After all the testing and working with the vendor I was told the settings are fine and to hire a master electrician because it was a wiring problem. So I guess I'm on my own to figure out their problem. Have not recieved my cable yet to use the software. Hopefully I can look into the settings and see what's going on. I'm off grid and live in the sticks, I would never be able get a Master Electrician out here. I will eventually figure it out I always do ....

 

[jeremyee]

I've been working with the vendor for hours with this problem. Completely talking down my system and rebuilding it. My problem is a little similar, I have 2 3k 24v growatt's in split phase, when I have an in rush of 12 amps or more my battery shuts down. But when I set it up in parallel it's fine. This system has been running fine for 9 months with AGM's. After all the testing and working with the vendor I was told the settings are fine and to hire a master electrician because it was a wiring problem. So I guess I'm on my own to figure out their problem. Have not recieved my cable yet to use the software. Hopefully I can look into the settings and see what's going on. I'm off grid and live in the sticks, I would never be able get a Master Electrician out here. I will eventually figure it out I always do ....

I personally think its a BMS issue but I am waiting for another 24V 200amp battery for testing. My plan is to convert to 48V and will take 2x 24v in series to make 48V and add more 48V going forward after I upgrade the inverter to 48V.

I hope to get in another 24V battery in the next 6 weeks for more testing.

 

[Zachrey]

Using the software, I noticed the settings for the BMS do NOT match the battery. The software sez I have a 48V, 50AH battery when it is actually a 24V, 200AH battery (or at least it is supposed to be). This might be WHY the battery is so sensitive to capacitive loads. A 50AH, 48V bank should not be able to deliver the same amount of inrush current as a 24V, 200AH bank and maybe triggers the BMS to freak out and shutdown.

I am hoping and praying that I can get the password for the software so I can change the parameters to match the battery and see if that solves the problem.

ANYBODY KNOW THE PASSWORD?

 

[jberger]

Did you use the READ command to pull the current settings from the battery?
The on screen references to 48V look like the defaults from the tools software, you need to read in the current settings to get them on the display.
The active battery screen shows 24V as expected.

 

[jeremyee]

The BMS setting look good on the one I have to the knowledge. Looks like the over current disconnect is 130 amps and the full_batt_cap is 199.

 

[Zachrey]

OHHHHH! I didn't dare click in the "Read" button for "Protect Params Operation (whole)". I can stop by their place tomorrow and see what happens when I click on it. Hopefully it won't insist on a password!!

 

[Tony Moser]

My 24 V 100 ah SOK battery arrived today. I connected to my system without the 200 ah EG4 connected, it ran the system perfect no faults with the current rush at all. The EG4 will not take a 11 amp surge, I knew it was the battery and not me.........

 

[Zachrey]

OK I clicked on the "Read" button for "Protect Params Operation (whole)" and for alarms and it came back with text in the box below the button all returning an "OK!" status. I guess I have to trigger the fault by plugging in a laptop power supply at the peak of the 60Hz sinewave and see if the battery shuts down again. Or I could cycle the power to the inverter and then click on the "Read" button for "Protect Params Operation (whole)" and see what it says, then. I'd be willing to bet it will be ShortCircuit_Delay, though..