question

bilgebay avatar image
bilgebay asked

Smart battery sense - incorrect temperature value received by the MPPT

Good day,

I have been using Smart battery sense a little over a month together with a MPPT 100/20, Smartshunt 500 and Cerbo GX. Smart Battery sense is located on top of my 100Ah Lifepo4 battery and transmits the battery temperature to the MPPT unit which is 2 meters away from the battery compartment.

Everything was working in harmony until yesterday. The weather was perfect and sunny but the MPPT wasn't charging my battery. After spending some time, I realized that the SBS was reporting a temperature of -18*C. Of course, MPPT was not sending any amperes to the battery in order to protect it. However, -18*C couldn't be true as I had access to another temp device in the trailer which was reporting +23*C. I was checking this remotely via VRM.

Today, when I came close to my trailer, I noticed that the SBS was reporting the temperature correctly, +12*C. However, when I enable the Bluetooth on the MPPT, the temp value received by the MPPT is still showing -18*C. Maybe, SBS needs an reset or a power recirculation but I wanted to share this here to ask if any of you had a similar experience.

I will appreciate your kind assistance

Best regards

Sedat Bilgebay


Smart Battery Sense
2 |3000

Up to 8 attachments (including images) can be used with a maximum of 190.8 MiB each and 286.6 MiB total.

6 Answers
mkuiken avatar image
mkuiken answered ·

Hi @bilgebay,

Can you send a screenshot of the VE.Smart Networking page from the MPPT?

I would like to make sure the MPPT isn't locked onto any other possible temperature sources in your setup. E.g. if Venus/Cerbo GX is sharing temperature information, then the temperature coming from the SmartBatterySense will be ignored. The same would happen if the SmartShunt has a temperature sensor connected to the aux input (and configured for temperature).

Sharing the VE.Smart Networking status as shown by the MPPT will help ruling this out.

Regards

Martijn

2 |3000

Up to 8 attachments (including images) can be used with a maximum of 190.8 MiB each and 286.6 MiB total.

bilgebay avatar image
bilgebay answered ·

Still the same today... any ideas or comments ?

2 |3000

Up to 8 attachments (including images) can be used with a maximum of 190.8 MiB each and 286.6 MiB total.

bilgebay avatar image
bilgebay answered ·

Hello @mkuiken,

Thank you for chiming in. You hit the nail on the head indeed. For some reason, MPPT switched to Smartshunt 500 for the temp data although SS500 wasn't providing any data as it's Aux Input was set to "None".

img-6538.png

After I cycled the Aux Input to "Starter Battery" then to "None" again, SS500 released the temp data line to SBS and all went back to normal.


img-6540.png


However, I'm still curious to know how this can happen without me changing anything physically on the circuit or any of the settings. I 'll keep an eye on the system and if it happes again I know how to fix it thanks to your great advice.

Thank you so much, much appreciated.

Best

Sedat


img-6538.png (407.3 KiB)
img-6540.png (454.9 KiB)
2 |3000

Up to 8 attachments (including images) can be used with a maximum of 190.8 MiB each and 286.6 MiB total.

mkuiken avatar image
mkuiken answered ·

Hi @bilgebay

Good to hear you were able to locate and fix the problem. Obviously this is unexpected behavior so please let me know if this happens again. Please also check the VE.Smart Networking status of the SmartShunt next time: does it report to be transmitting battery temperature? And if so, is the temperature then also shown in the main status page of the SmartShunt?

Also, do you remember if you performed any firmware updates to any of the devices just prior to this issue happening? Or possibly a reboot of any of the devices you happen to observe?

Oh and last question: what's firmware version of the SmartShunt Bluetooth Interface (so not the v4.08 version of the Shunt itself)?

You can check the firmware version on the Product Info page in the Settings menu but you can also send a service report so I can look it up (see https://www.victronenergy.com/media/pg/VictronConnect_Manual/en/troubleshooting.html?utm_source=offline&utm_medium=qr&utm_campaign=qr%20code%20products#UUID-98bc9211-902b-01a0-96b9-1f314c4d63c5 if you don't know how to make a service report).


BR

Martijn

2 |3000

Up to 8 attachments (including images) can be used with a maximum of 190.8 MiB each and 286.6 MiB total.

bilgebay avatar image
bilgebay answered ·

@mkuiken

Hello Martijn,

Thanks, for sure I will let you know if this happens again. I did a reboot for the whole system but this was on the 21st of March, 5 days prior to this anomaly which occurred on the 26th. Prior to this, the temp value was normal and the MPPT was charging the batteries during day time. Please see the graphs for the 7 days period below.screen-shot-2022-03-30-at-32756-pm.png

I don't remember performing any firmware updates. I will check the other points when I'm near my trailer.

Thanks again and best regards

Sedat

PS I have purchased a temperature sensor for BMV702/712 because I want to see the battery temp on VRM. I will use the SBS else where or I will sell it to a friend.

PS2 I decided to make use of this incident to test my new parallel battery bank which comprises of 2x 100Ah Lifepo4 batteries. I have disabled the MPPT to see the discharge performance... it wil take another 4 days, at least :)


2 |3000

Up to 8 attachments (including images) can be used with a maximum of 190.8 MiB each and 286.6 MiB total.

bilgebay avatar image
bilgebay answered ·

img-6544.png


... and the Bluetooth Interface Firmware version is 2.37.

Best

Sedat


img-6544.png (222.9 KiB)
2 |3000

Up to 8 attachments (including images) can be used with a maximum of 190.8 MiB each and 286.6 MiB total.