question

ceridwen avatar image
ceridwen asked

System shutting down when batteries reach around 26 degrees..

We have a fairly new set up on our narrowboat with 2 X 150 AH Lifepo4s. Charging from engine or solar. We are using a relatively low amount of power, and the batteries have barely been below 80% charge. A couple of weeks ago we noticed the system seemed to shut down for no obvious reason. At the time we thought it coincided with new appliances being added, eg a 12v fan or using a new tool/phone charger (via the multiplies). Now it is more frequent and we think is linked to charging and battery temperature. It happens when we enable the solar to charge or when we run the engine to cruise or heat water in the calorifier. And it always happens when the batteries reach around 26 degrees or go above this. The red LED (Cell <4V or temperature) on our VE BUS BMS comes on at the same time. Whatever it is, this doesn't seem like it should be a problematic temperature, but as soon as the system shuts itself down we're then powerless to do anything; either to investigate the issue, or to use basic on board facilities.

BMSbatteryerrorSolar Paneltemperature
1 comment
2 |3000

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

svcanna avatar image svcanna commented ·

I'mm having the same issue. VE.bus BMS showing a red LED and disabling charging once the batteries hit 25C. That seems like a very low temp to disable charging.

0 Likes 0 ·
2 Answers
ejrossouw avatar image
ejrossouw answered ·

It will help if you can provide screenshots of settings, maybe all the equipment and how it is connected. Is the BMS the "master" and do you have other temperature sensors e.g. 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.

jasontav avatar image
jasontav answered ·

That error is Cell>4V or temperature.

Are they Smart LiFePo4 batteries?

Can you see the individual cell voltages and temperature that the battery is reporting?


Its more likely to be a cell over 4V than temperature IMO, as the BMS uses the temperature from the batteries not the multiplus to determine if it should allow charging, and the temperature is set to 75 degrees C for a cut off event i.e. pretty hot.
2 |3000

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