[Resolved] Renogy problem - BMS drift, 100%-0%-100%

[Periscope007]

I am having a problem with my set up, appreciate any help
200w solar
100A renogy lithium battery
Dc-Dc 50s with BT2
1000w renogy inverter

The problem is: green led indicating service battery full is on. Blue led lithium battery type is on. Red solar led on
battery charge level (on app) for example around 70%
If I remove the Dc-Dc 50s from the set up and reinstate it after 5 minutes then things work normal, ie the service battery led is yellow, the solar charging led is slow flashing red and the app indicates a good charging level from the solar panel. Once the battery is up to 100% then the service battery indicator changes from yellow to green, where it remains until the Dc-Dc 50s is once again removed.
Currently in this set up, whilst the van is not mobile I have in constant use a fridge switching on/off approx 4A and a tracker.
Everything was good until winter appeared, this is when things started to go 'tits up', contacted Renogy (do not ask me how) and they wanted photos, why?? I thought my explanation was better than any picture could reveal, anyway, as I understood from their correspondence, the system needed resetting, no magic button or swipe in an app but disconnect and start again.
What am I missing? Doing wrong?

Thanks for looking

 

[Dellmassive]

Post some pics of the install.


And screen shots of the app screen.

 

[Periscope007]

Thanks for quick acknowlegement. I take by your request for pics and screenshots that there is no simple reset sequence i am failing to follow? It's a seat out job for those pics so will do as soon as possible, thanks Dellmassive

 

[Dellmassive]

it could be BMS drift on the battery, showing 70% but its actually 100% - battery BMS recalibration reqd.

DC50s possible reset - disconect all power feeds from van, leave 5mins, then capacitive discharge all pins to the units 0v.

pics of the install abd battery setup will answer a 1000 questions,

as will the App screen shots.

+++++++++++++++


DC50s:


green led indicating service battery full is on - battery full (yellow - battery normal )


1. Red to Yellow: When the voltage reaches 12.2V under voltage recovery2. Yellow to Red: When the voltage drops to 12.0V under voltage warning3. Yellow to Green:

A. When it reaches constant voltage charging state, the charging current issmaller than 3A, lasts for 30 seconds;

B. When the charging current is higher than 3A, it keepscharging until it reaches constant voltage state and the current drops below 3A, lasts 30 seconds.




+++

Blue led lithium battery type is on - blue indicates lifepo4 setting

-





+++


Red solar led on - that indicated the dc50 is charging from solar




+++

charge profile.





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https://store-nkm2yhe9h8.mybigcommerce.com/content/RBC3050D1S-Manual.pdf

.

so here all looks ok.

 

[Dellmassive]

so are you saying the battery charges via solar to 100%,

then drops down to 70% and the DC50s doesn't recharge again?


.....


how low have you get the battery go?


have you got any other battery monitor? - ie BM2?

+++++

 

[Dellmassive]

Battery Monitoring -- How I Done It --

Battery Monitoring -- How I Done It -- Part #1 Battery monitoring is a very important part of your 12v system . . . . whether its just the vans starter battery or your leisure setup keeping an eye on the power in your battery bank will keep you from breaking down and make sure your weekends...

www.t6forum.com

 

[Periscope007]

Thanks for the time you are giving me on this, I understand where you are coming from with the screenshots now. Regarding the problem, the battery was down to 40 something percent a couple of weeks ago (green led battery lit) , Disconnected dc-dc50s wiring but only discharged on one of the terminals. Reconnected everything and connected ac-dc renogy charger which charged the battery in the daytime but I left it on for over a day. I do recall the cell voltage was .1v down on one of the cells before I charged but they were all the same when charging completed. I've just taken the attached screenshots before the rain sets in. Everything seems ok to me, charging off solar (yellow led battery status) and it is in the shade also very overcast presently. May be a day or two before the sun gets me to 100% since I'm not planning on driving anywhere. So , from the point of full charge (green led) how depleted does it go before the green led returns to yellow?
I do have a BM2 (on the shelf, not in the van)
Thanks once again

 

[Dellmassive]

gotcha, ,

well the pics above look good. - so far so good.


see if you can get that BM2 fitted to the leisure battery.

a few pics of the install will help,

ans a screen shot of the DC settings page.

.....


as far as:

Yellow to Green SOC indication:

A. When it reaches constant voltage charging state, the charging current is smaller than 3A, lasts for 30 seconds;

B. When the charging current is higher than 3A, it keeps charging until it reaches constant voltage state and the current drops below 3A, lasts 30 seconds.


+++




+++

 

[Periscope007]

Currently in a monsoon so I'll sort the BM2 when weather permits me to lift the seat. will get some snaps, too.


Have a good weekend

 

[drinfinity]

My setup is doing something similar. Bluetooth 100Ah Battery showing 66% on the app, but at 14V and above. I’m guessing it is just state of charge not calculating correctly on the battery, given the voltage is high (measured by the app and a meter). I’ll get a monitor for the DCDC 50 when Renogy have them back in stock.

 

[Periscope007]

Morning reading 66.1% Dc-dc50s battery led green and solar panel led flashing red boost charging. Disconnected everything and fitted BM2. Wired everything back up - yellow battery led on. Selected BM2 app and checked alternator charging ok (is there a different setting for Lithium?)
Switched ac-dc charger on- (red led). when dc-dc50 app showed 75% the yellow led (dc-dc50s). switched to green the red led on the charger switched to green. Does the battery need a serious talking to, and if so, how?

 

[Dellmassive]

its looking like your Renogy battery might need a re-calibration.


your showing the battery at 14.4v with 0A going in - so fully charged.

but your SOC is reading 75%

your cell voltages are all good at 3.6v.







+++++++++++


so to recalibrate the battery you need to drain it fully . . . so its totally dead and shuts down.



then you need to fully recharge it for 24hrs/48hrs ( depending of the rate of charge )


until the battery is cuts off charge or is drawing less than an 1Amp.

at that point it should be fully charged, and the BMS should reset to 100%


+++++++++++++++++++++++

 

[Periscope007]

Thanks for all your time and help, will let you know how it goes. I owe you one
cheers

 

[Periscope007]

Everything is good. Big thanks for your assistance, @Dellmassive

 

[Dellmassive]

Awesome. Glad your sorted.

Can you post some new screen shots of everything working well, mainly for future reference.

And for others that my need to re calibrate there Renogy lifepo4 battery.

.

 

[drinfinity]

My BT2 module arrived for the DCDC 50 unit, so I can see what’s going on with mine now. The charging current seems to be under-reading by about 1 amp at the battery end. I wonder if anything will happen when the battery SOC calculation shows 0% even when the voltage is at > 14V?

 

[Dellmassive]

My BT2 module arrived for the DCDC 50 unit, so I can see what’s going on with mine now. The charging current seems to be under-reading by about 1 amp at the battery end. I wonder if anything will happen when the battery SOC calculation shows 0% even when the voltage is at > 14V?

post some screen shots of the app and setup.

 

[drinfinity]

Here we have Solar trickling into the leisure battery (100W panel, miserable grey wet day). Even on a bright day, the battery records fewer input amps than the charger. No load on the battery other than parasitic drain from heater controller, and a USB port with nothing plugged in.

I never manage to catch it charging from the alternator. There is ignition live at the charger (measured with voltmeter) but it insists on trickling in from the solar, rather than filling the battery from the alternator on the long drive back from Wales yesterday.

Lights on the charger show blue indicating Li setting, Green or yellow indicating charge state of leisure battery, solid red for solar charge, and slow flash red for charging starter battery or off when charging leisure from solar.

Battery has fused connections to load and charger, and direct connection to 240V charger.

Apologies for untidiness around Renogy, I had to move various VW connections out of the way to get to the port for the Bluetooth. No impact on the power connections.

 

[drinfinity]

Having said I don’t catch it charging from the alternator, given max charge power is 438 W it must have done, since my solar panel is only 100W!

 

[Dellmassive]

Can you get a screenshot of the dc-dc setting page pls.