So with this heat wave that’s hitting the US hard right now, it got me wondering if last year’s overheating Yarbo / non charging Yarbo issues would pop up again.
I deliberately had my Yarbo do a 2 hour mowing job today to see what happens, and track the data on Home Assistant.
The bottom line is, my Yarbo worked the job in the 95° sun today, and never got too hot. No issues at all.
What about charging? The charging never stopped either, and the batteries never overheated. I monitored and graphed the battery cell temperatures, and the graph line was pretty much flat. Peak battery temp was 114.8°.
Ok. After reviewing the charging curve data, I do see where the charge rate was throttled from ~535 watts down to ~235 watts almost immediately after charging started with the warm battery. The throttling occurred within 4 minutes of Yarbo docking and the charge process starting.
Charging never stopped, but it did slow down to avoid getting the battery any hotter.
We optimized the charging logic in last year’s update to better manage battery temperature during charging. It’s great to see your data, and we’d also love to see more members of the community share their experiences and observations under these hot weather conditions!
So far, the integration has been really good. I’m not using it to control the robot or automate anything yet. I just use it for data logging and monitoring, and those aspects have been perfect.
I’d love to see a category for “robot docked” yes/no or something like that, but it doesn’t currently exist. Aside from that, the API datapoints are pretty informative.
I mowed in the afternoon two days ago. Run time was over three hours. The Yarbo completed the mow. After it went back to the charging pad, I checked and the battery temp was showing 58 degrees C. It did alarm out and resumed charging overnight after it cooled down.
I did a four hour mow yesterday. Outside temperature was 88 degrees F., party sunny. Initial battery temperature was 34 degrees C. The battery temperature rose to 44 degrees C over the first two hours and then stayed there until mowing was completed.
All yarbo did was slow down charging as a band aid to keep battery temps down. The heat comes from charging a battery with no cooling on the battery, not even a place for heat to escape.
What was interesting to me was that the previous hot weather mow, the battery temperature was up to 58 degrees C. According to the wiki, it should have stopped mowing. This is from the wiki:
What happens if the battery overheats?
During operation
At 113°F (45°C): Temperature protection activates.
At 122°F (50°C): Yarbo will stop working.
At 140°F (60°C): Automatic shutdown occurs.
During charging
Above 50°C: Charging suspends automatically.
Between 45–50°C: You can still start charging manually via the app.
Last year I found that removing the battery cover made a significant difference in the battery’s temperature while charging.
But I ultimately determined that at least where I live, my Yarbo will keep charging during the hot summer with the shaded charging location and the dog shelter providing additional shade.
That said, the charging rate does throttle down when things get too warm.
I have one out in the sun and one in the back yard mostly shaded. There was almost a 10 degree difference between the two just sitting on the dock. Amazing what not being in full sun will do.
