Renogy Battery Monitor Problem

[padredw]

Report on running Air Conditioner -- 15000 btu with ezy start

ran about 5 minutes before causing trip and shut down. (Phone/camera was plugged in at house so no photo. My best recording.)

while running - 1.3 Kw - 103 A 195 Ah remaining
--------
@ tripped 0% % shown, 0:00 Ahrs, 0:00 (time) 12.5 v-4.34 A display blinking.
-------
reset not long then still showing 0% capacity and 0.00 Ah remaining -- same as with microwave.

I'm sorry about lack of actual display. My recording is not so good.
I am now convinced about tripping.

 

[GXMnow]

In the 5 minutes before it tripped, did the display show a decent capacity?
I suspect, once it trips, it goes dumb.
What brand are the batteries? Are they both identical, brand, age etc.? Are they internal BMS like a Battle Born? I wonder if they are just going into an overload condition. Can you measure the voltage right after the trip and see where it goes dead? If you still have voltage at the battery terminals, the trip is happening external. If the batteries are shutting off, that would answer all the questions. And they can't take all of the current. Do you have a load of about 400 to 800 watts you can test with? Maybe just try one battery at a time, maybe one is actually not working and the other is shutting down at 100 amps? If both batteries will run 50 amps on their own, then we know they are both good. This also puts half load on the inverter, so it should stay working without a problem.

 

[padredw]

What brand are the batteries? Are they both identical, brand, age etc.? Are they internal BMS like a Battle Born?

ExpertPower 12V 100Ah Lithium LiFePO4 Deep Cycle Rechargeable Battery | 2500-7000 Life Cycles & 10-Year lifetime | Built-in BMS​

Two of these wired in parallel to produce 12v.
These are identical batteries and only a few months old. Let me say that the batteries have always tested with multimeter at same voltage as displayed: note the image below. The capacity and % are wrong but the voltage is still 13.2 and the batteries had a multimeter reading consistent with the display.

In the 5 minutes before it tripped, did the display show a decent capacity?

Yes, I recorded (on paper towel, hope it's right) 13.2 just at tripping. 13.2v - 4.34 A

I suspect the inverter, but I am not an electrician. I must admit that I tried to limit my cost at the inverter.

WZRELB 2000W 12VDC 120VAC Pure Sine Wave Power Inverter ​

 

[GXMnow]

The basic rule on this forum seems to be a 50% rating factor on the cheaper Chinese inverters. So the 2,000 watt inverter will probably be fine at 1,000 watts. Trying to push 1,600 watts??? It could be the weak link.

 

[padredw]

This is what I have begun to suspect. Is there any way to confirm this?

 

[padredw]

Just emailed the installer of the system. He says they did not install any thermal:

We didn't add any thermal breakers in the system so it must be in the inverter. I'm sure it has some kind of thermal overload protection.

While I'm on. I tested for reset of the power and of the monitor display. Power within a minute. Display seems to be related to battery capacity.
Photo 1 below. Charging has been on several minutes, showing incorrectly, I believe, 1% and 2.3 Ah.






Photo 2 as near as I could capture the moment of reset of the display

 

[padredw]

From the Amazon web site:

About WZRELB Professional manufacturer for pure sine wave power inverter for 10 years provide prompt reply friendly customer service and 18-month Product details DC input 12V DC input range 10V-15V Efficiency 85%-90% AC output 120v Frequency 60Hz Socket Dual US type Low Voltage Alarm 9 5V-10 5V Low Voltage Shut Down 9V-10V Over Load shut off recover manually Over Voltage Shut Down 15 5V Cooling Ways Cooling Fan will run when the temp is over 50 degree Celsius Precautions 1 Please do not connect the inverter with the grid power and a reverse connection of positive and negative is also forbidden 2 Please do not overload If your applications are inductive loads please choose the inverters whose continuous power is 3-7 times higher than the watts of your appliances If you want to power up a refrigerator we suggest you use 10 times higher power inverter 3 Please turn off the load first then turn off the inverter And as there is a soft start function please turn on the inverter first then turn on your loads or the output may not stable at the first seconds 4 For a red light flashing it remind that the input voltage is a bit high 5 Please use the set of standard battery cables we sent or a full output may not be There are build-in fuse for safety concern the fuse come with package are just spare parts

 

[GXMnow]

The pictures make sense.
The first one looks like the battery was quite low. The charger was pushing 42.6 amps in, and since it had only been running a few minutes, it put 2.3 amp hours into the battery. By the math, it was charging about 3.2 minutes. The time looks like an estimate until full at this point. 4 hours and 37 minutes at this charge rate. That looks about right.
In the second picture, the charge current has fallen to 32.9 amps, the battery is very close to full. Estimating another 32 minutes until done charging.

Got to love those English translations. A microwave oven is a fairly inductive load as it uses a transformer to produce the high voltage for the magnatron. So by their own rules, you need a 5,000 watt inverter to run your oven that draws 1,600 watts. Ouch. My Schneider XW-Pro is a 6,800 watt inverter, it weights 125 pounds. It is built to a very different use case.

 

[padredw]

Thank you, GXMnow, for hearing me out on this. I believe I do not have an inverter capable of running this microwave oven so I'm not going to worry about that for now. Your analysis of my many photos and descriptions has helped me to reach that conclusion. I started with a monitor display problem--and I still have that problem as well--but it looks like the fundamental problem is the inverter. I think I'll put this one to bed with one final question. Do you think an upgrade of inverter will be supported by my system* or should I stick with limitation of no use of microwave?

*
2 lithium 100 Ah batteries
2 100 w solar panels
Victron Energy BlueSolar MPPT 100/30 Charge Controller
Victron VE. Direct Bluetooth Smart Dongle
Renogy RBM500-G1 500A Battery Monito

 

[GXMnow]

I pulled up the spec page on those batteries, and each one says it can output 70 amps continuous, and up to 100 amps for 10 seconds. With the 2 in parallel, I would say 105 amps continuous should be safe, with a surge to 150 amps. That is my 50% more power when you double the battery.

105 x 13 volts = 1,365 watts safely. 1,950 watts for short term. If the two batteries balance very well, you may get away with a bit more, but as a design goal, I think a 2,000 watt inverter is all it will support without more battery. A better quality 2,000 watt inverter might do the trick, but you are running into the battery limits. If all the cables were exactly the same resistance, and the internal cells were perfectly matched, the long term power, is still just 140 amps x 13 volts = 1,820 watts. And at 90% efficiency, that is only 1,638 watts. If you need the microwave, it may need a third battery and a 3,000 watt inverter.

 

[padredw]

A very hearty thanks to GXMnow who has faithfully walked with me through this journey. His latest response provides a good time to consider the journey complete. It is not so much a problem solved as it is multiple problems resolved. Using that microwave was never a big deal, but the knowledge about the failure has become of value to me. So I can rest content with a small system that does 99% of what I ever wanted it to do and quit worrying about that 1% that we can so easily work around and live with.

And to any and all who may have followed this journey from the sidelines, I hope you have also learned along with me. For you, it may help to see a brief summary: We have a 34' fifth-wheel trailer. We are NOT full timers and never will be or wish to be. Our small solar system will never be central to our use of our trailer, but it does allow us to spend some time in beautiful locations without hook-ups. For example, we spent several days INSIDE the Rocky Mountain National Park last month. We would not have been able to do that without our solar additions. Yes, it is minimal but it worked great. Our batteries supplied the power we needed and our solar panels replenished that power each day. There may be other RVers who might be considering a small "hybrid" system for only occasional use in locations without electric hook-ups. I am glad to share our experience and will be happy to answer any questions.

Thanks to all, and good bye for now. I may see you around the corner!

 

[padredw]

UPDATE

GXMnow​

I decided to run some tests this morning with some interesting results. I connected the inverter and the Battery monitor read: 99% full on capacity and 13.2 on voltage. Then I turned on the microwave. It did NOT trip off, nor did the inverter, BUT the monitor dropped IMMEDIATELY to 0 %, 0.0Ah, -131A, 1.5 Kw being drawn (which would be normal for this MW).

The MW finished normally (about 1.5 minutes as test only) but the display remained as follows: 0.0 Ah, 0 %, -1.66 A, 21 W (normal draw from inverter,etc.)

I then checked voltage at the batteries with mm which showed 13.11v

I then ran a second test using an electric heater with similar results: (monitor DID NOT reset) it read same as after the MW test above before I started heater test. During test: -131 A, 1.5 Kw draw. Heater ran normally, inverter did NOT shut off. Display on monitor remained 0 %, etc.

After both these tests, with inverter turned off at switch, monitor showed 0 % capacity, 0.0 Ah, -1.64, 0.18 A, and 2 w draw.

This is as I remember the use in the summer in Colorado. That is, the MW worked, but the display went crazy.

The problem is that with the first use of the MW I lose my ability to monitor my battery capacity which is a problem when actually boondocking.

The monitor is Renogy as described in my posts earlier in this thread. What could cause this behavior? I will appreciate any comments or suggestions.

 

[classic_massok]

@padredw, I just had a very similar issue to what you have been describing. I was able to get on the phone with Renogy's technical team and get some more information about why it happened to me.

My monitor configuration:

• CAP: 400Ah
• HIGH V: 15V
• LOW V: 12.3V
• ALARM: 200Ah

As you can probably tell by my high/low voltage settings, I was trying to alarm for too high or too low of float voltage. What I did not realize is that these configuration properties are not alarms. According to Renogy, they are threshold voltage readings that indicate to the monitor that you are either fully charged, or fully discharged.

If your voltage drops below your low voltage setting, your capacity will immediately fall to 0%/0Ah.

If your voltage exceeds your high voltage setting, your capacity will immediately jump to 100%/Full-Ah (whatever your capacity may be).

I'm not sure if this is what happened to you or not, but I wanted to at least drop this in here in case this is what happened to you. Best of luck with troubleshooting either way!

~ Marcus

 

[padredw]

Thanks, Marcus, This is very helpful. We have not used the trailer for some time, but will be making a short trip next month. I will check the settings on the monitor while on that trip. I appreciate your willingness to share. If I find out more about my situation I will post here sometime after next week. Did your monitor display correctly after you made the adjustments?

 

[classic_massok]

@padredw, no problem at all! That was the one difference b/w your experience and mine. My monitor did not reset after applying a charge.

I will tell you that when I talked to Renogy technical support, they did offer to replace my monitor (though after more conversation, I realized I just needed to replace my manual reading skills). Let me know how testing goes! I'll see if I can be of any other support if this doesn't resolve your issue.

 

[padredw]

Thanks, Marcus, will keep in touch.

 

[walter-]

Note: The feedback from Marcus makes sense.
When reading on what happens I was believing it was a monitors issue.
What I expect: for some reason at some load, the battery voltages dropped below the 'low' setting of the monitor. At that moment the Monitor decides to set the capacity to 0%.
Note that it is possible there is some issue in the system: at high currents, it is possible there is 'high' voltage drop for some reason. This could be short, but short enough for the monitor to put the battery to 0%.

 

[ooodeeooo]

I don't know if this will help, but I had the same issue with my monitor only it was the water pump causing it to reset itself. The problem was I had the positive wire going to a fuse panel. Once I wired it directly to the battery I no longer had that issue.

 

[Jslort]

Just to confirm what Walter- said, it seems to be the way it is designed. I personally would avoid setting the low voltage, just leave it on zero. Reason being, I'd rather not have to then wait for it to get some sort of charge so that it will reset the total AH's. Also, if the alarm goes off for any reason it seems to just continuously keep beeping till the conditions are changed (I turned it off by pressing the up arrow for 3 seconds to make it think that the battery was full), I believe because one set of conditions (low voltage) triggers the other (resets AH's to zero) so that even if the voltage is restored the alarm continues to go off due to the fact that it thinks the battery is now lower whatever you set for your amp hour warning. One other thing, apparently the high voltage setting is so that the unit will automatically reset to 100ah once that voltage level is reached. This could be useful, though if you set it originally at the start then probably in the end also irrelevant. I personally would just set the ah's of the battery and leave / set all the others to zeroes. Cheers.

 

[@thewanderingshores]

Just to confirm what Walter- said, it seems to be the way it is designed. I personally would avoid setting the low voltage, just leave it on zero. Reason being, I'd rather not have to then wait for it to get some sort of charge so that it will reset the total AH's. Also, if the alarm goes off for any reason it seems to just continuously keep beeping till the conditions are changed (I turned it off by pressing the up arrow for 3 seconds to make it think that the battery was full), I believe because one set of conditions (low voltage) triggers the other (resets AH's to zero) so that even if the voltage is restored the alarm continues to go off due to the fact that it thinks the battery is now lower whatever you set for your amp hour warning. One other thing, apparently the high voltage setting is so that the unit will automatically reset to 100ah once that voltage level is reached. This could be useful, though if you set it originally at the start then probably in the end also irrelevant. I personally would just set the ah's of the battery and leave / set all the others to zeroes. Cheers.

Jslort, I know this is an older thread but wanted to say thanks so much for your post and all the others on this thread. I was having the exact same issue as padredw with my renogy battery monitor. I discovered this thread last night after just "dealing" with the zeroing out of the monitor on heavier draws. Last night I went in and adjusted the low voltage threshold to 0.00 so not to trigger the alarm. I ran the 1500w airfryer for 10 mins today and no alarms and no zeros... this is wonderful. Thanks again.