We have a new Husqvarna automower 435X AWD NERA and almost right away the mower started to error all of the time. Our service technician contacted Husqvarna and they said the problem was due to the extreme heat we are having in northern Portugal. They suggested running the mower after 6 PM and before 10 AM during these really hot times. That did seem to solve our problem.
I have our mower connected to Home Assistant (Husqvarna Automower) so I do have the capability to use that to return the mower to it's docking station and shut it down until the temperature cools down. My question is does anyone know what that magic temperature is that I should trigger this shutdown? And second question what would be a reasonable temperature to resume mowing?
I don't know what kind of grass you're dealing with, but many lawn grasses shouldn't be mowed at all if the temperature is above 90°F (32°C), especially if the heat is combined with drought.
Beyond that, It's going to depend on a few more factors than just the air temperature, because the real question is "How hot is the battery?"
How hot is the battery before mowing? If the storage/charging location isn't shaded, the battery may not be getting a proper charge and will get hot faster when it mows. Does the Husqvarna integration provide a battery temp sensor?
How long it will be running?
How hard will it be working? Dew-laden or wet grass is more resistant than dry grass which causes the battery to heat faster. The same goes for deep cuts vs. high cuts.
Unfortunately no battery temperature.
I do see the battery charge and it does fully charge after it docks before running again. This is even in the high temperature times.
The installers chose an open (unshaded) area so there is good GPS connectivity.
Right now it's running on the schedule I mentioned in my post. Normally it runs longer until it's down to about 30% battery and then goes home for a recharging nap and resumes after that.
We get little rain in this area in the summer. Winter is our rainy season. We have to rely on irrigation which needs to be scheduled when the mower isn't running.
When I stick to the schedule recommended by Husqvarna the mower doesn't have any problem with our hills and grass length.
Tomorrow we should be out of this current heatwave so back to normal temperatures which are usually quite moderate summer or winter. I would just like to schedule some kind of safety automation to shut the mower down when our outdoor temperature sensors detect these unusual high temperatures rather than totally changing the schedules each time.
I would contact husband and ask rrecommended operating temperatures. As previously stated the unit sun shining on unit be be raising internal temp. I would expect it can handle 40-110F or so.
Cutting at night, late evenings and mornings may be the way. Avoid 2 hr after sun up to about 1hr before sun down
I checked the manual too before I bothered anyone. It's Sunday and I had time to set up an automation so was hoping someone else went through this and knew the answer. I will contact Husqvarna to see what they recommend. Our temperatures only got in 90's. These are our normal wonderful temperatures:
If those are your normal summer temps and we're talking about lawn grass that isn't specifically a high temperature tolerant breed... I would set the cutoff at 90°F and see how it goes. That should be within the safe zone for the mower and will prevent stressing the grass.
A simple Google search finds the recommended operating and charging temperatures...
Perhaps not in the manual, but certainly in the support documentation.
The 'magic temperature' is 50°C, as measured by an internal sensor. Given that this, in direct strong sunlight, will be 5-15 degrees higher than ambient, I would expect issues when the air temperature exceeds 35°C, which it has been doing across many parts of Europe recently.
Given that direct strong sunlight, particularly in the lower latitudes of southern Europe, will raise temperatures, several locations have suffered issues with melting tarmac. Admittedly this is black, but then if it gets that hot, so will a dark plastic lawnmower.
Only mad dogs, Englishmen, and robotic lawnmowers go out in the midday sun.
So far we've had it less than a week and encountered this heat related problem. Although we read that people were unhappy with the response with Husqvarna as a company we've been really happy with the company we've been working with. When we told them we had a problem, they sent out a technician right away and when the diagnostics that they ran didn't show a problem they had no problem communicating directly with Husqvarna and came back with the heat related reply to us.
We do have a difficult yard for a robot to navigate and the 4WD does an amazing job with the hills, dips and mounds. We have a fairly large yard that has not been maintained well before we moved in so there are some really large tuffs of junk grass that the unit has had collisions with. Even though it might get stuck on one of these it does an amazing job of trying to remove itself from the problem before giving up and reporting a collision to us. It backs up and turns in all directions before giving up. We've been digging out a lot of these problems grasses but many more to tackle.
As for HA and Husqvarna all I've had the time to do so far is put the exposed sensors, etc. on my backyard page. I haven't even had the time to create the automation I would like to create to send the unit back to the docking station when it's too hot so right now I'm not the best person to ask about this. If you take a look at the integration documentation you will see all of the available exposed elements. The integration was well documented and I had no problems installing it. Right now I have a calendar showing the scheduled times and where the unit will run. I'm hoping to find a way to edit these schedules in HA rather than the phone app. Once again - I just need some time to find out if anyone has already created a blueprint or if I will be able to work something up myself. I'll let you know if I run into any difficulties with HA and the mower.
We were having a terrible time with disappearing lawn gardeners so it is such a relief to know the grass will be cut regularly.
A dedicated little house for your mower to rest, recuperate and recharge may extend its life considerably. There you can mount a temperature sensor that will accurately measure the sun temperature it is being exposed to, and use that in your HomeAssistant automation.
While modern plastics and paint finishes have improved considerably, weather exposure, either end of extreme heat and cold can still affect them. Look forward to a long life of well mowed lawns.
Using smarts like economically measuring grass height is still a nice feature that may have to wait for technology to catch up with, but when you were using human gardeners, did you schedule mowing based on days elapsed since last time with seasonal tweaks, or visual observation on when the jungle got too wild?
I would guess the largest incline is around 30 - 35 degrees. Our total mowing area divided into 1 large and two small areas is a little over .6 acres. I have to mention that the yard was not maintained at all before we moved in. There are a multitude of heavy clumps of weed grass all over that the robot has a tendency to get stuck on. I am gradually digging them out and evening the surface.
Here is a map of the three areas.
The small area at the top took a total of around between 45 and 90 minutes. The medium area took around 5 hours.
Here is a photo of the robot on a lesser than max incline.
