BUT, at least you KNOW it is properly aligned now! 
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When does it start charging again? I’m at 49c and it still fails to charge.
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48c seems to allow it to start charging.
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Still charging with a temp of 53.
Stills shows temp of 53 but stopped charging. Made it to 62%. Sent Yarbo back to work.
i would not recommend for the longevity of the batteries. I’ve flown heavy drones in adverse wind but damaged batteries doing so in the hot conditions even as i was mindful to let cool before recharge.
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oh man. so how does it handle having the battery door open during a charge?
Wouldn’t Yarbo’s BMS protect the battery? @Yarbo-Forum?
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Was around 97 or 98F here today. I mowed late morning and then late afternoon into the evening. The battery got to 45C in the black tarp doghouse mid-day. I got the mower out for the late afternoon at around 94 degrees out when the sun started ducking behind trees, and the battery went down to about 41 while out there mowing in the shade.
I wouldn’t have the riding mower or push mower out in these temperatures in the direct sun, so not having the Yarbo out there was no big deal. The difference was the Yarbo actually did some mowing – on the nasty days I wouldn’t bother and just wait for cooler weather.
Tomorrow is supposed to hit triple digits here. Yowch. Yarbo may find itself in my garage on the wall charger after a morning mow.
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Out of curiosity I did some quick research through some other mowers owners manuals.
Here are the charging temperature ranges for the Luba from the manual.
For the Luba 2:
For the Terramow:
As you can see, it’s a battery chemistry limitation and not a design issue. A brief Google search about the Luba 2 and temperature and lots of people complaining about failure to charge due to overheating.
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Yeah definitely agree that temperature limits are needed to protect the Battery and the Yarbo itself.
Though I do believe there should be some active cooling methods on the unit.
I have a large yard, so only 2/5 schedules that I have can finish in 1 battery charge.
so the other 3 schedules(days) the unit has to return home and charge before it can finish.
Unfortunately with weather ( only been in the high 80’s and low 90’s ) the unit fails to charge for ~8 to 10 hours. It returned back to charge around noon. and then went out to finish the job around 10pm ( still had ~3 hours remaining on the job ) I ultimately canceled the job around midnight as it already mowed most everything I cared about ( just perimeter left ).
Note I did check battery temps while it was running. When it hit ~22% battery ( been out mowing from 100% ), battery temp was 42.
As we go into summer. Day temperatures are only going to get hotter, and I suspect the unit will not charge until night again.
While I will continue investigating “cooling solutions”.
- Currently I plan on building a small pvc structure holding shade cloth to try and give the charger a place out of the sun.
- I have also questioned the idea of a solar fan installed in the core of the yarbo ( 2023 model ) as it looks like there is space for one.. I dont think slot for the battery would allow enough airflow around the battery to actually provide any cooling. Though a peltier cooler would.. be interesting..
I question if there might be a “slow charge” profile that could be created, where instead of disconnecting from the charge entirely, reduce charging current to prevent ( reduce likelyhood ) of over heating while charging.
EG if over 45 ish, reduce charging current to 1/2 or so.
While yes this will take longer to charge than say full power..
If the battery overheats and you have to stop charging for.. 10 hours… I would much rather slow charge for 6 or 8 hours.
The App itself also needs to be updated to better display this overheating issue while charging as well. EG show a differnt icon saying “paused - Overheating” or something other than just… not charging.
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The error message is same for misalignment and over temperature. This is known issue.
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That’s what 50 C shutoff does. Since there no cooling, there nothing else it can do. Running the battery at it’s temperature limit all summer will not be good for longevity.
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@ken.w.gregory - Has that continued to work alright? I would think the non-uniform reflective surface could actually cause GPS reflections potentially unless grounded (same reason it reflects heat would reflect any EM signal). If it doesn’t have any impact on the GPS it’s an interesting solution.
Still agree with another post that something with active cooling would be a great solution. I could envision something similar to either a weather sealed solar powered fan (similar to RV or smaller version of attic fan) or something that’s weather sealed and fits between the connector and the battery to siphon off some power could be viable solutions.
I also saw someone suggest a weather resistant fan behind it was something he was exploring. Home Assistant integration to notify when on the base could be a really interesting control solution for something like that.
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@Wes too soon to tell.
The last two temp readings are charging all the previous readings were mowing. Mowing doesn’t seem to be an issue, but charging definitely raises the temp.
It did manage to completely charge to 100%.
I “feel like” it may have helped a little.
I did mow a work area with the reflectix in place. I noticed no loss of GPS. Other the normal too close to the house on the east side.
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As one would expect
So, update on the color tactic -
Outside temp 92 in sustained direct sunlight. One cellphone overheated in about 4 minutes.
Batt cover removed. 2x 8x11 sheets, Perf slots in the one over the battery, good ducted fan blowing ambient air downward from above.
Installed paper after overheat, walked away with no charging at 53deg, 45ish % charge.
Came back 25ish min later, batt is now 53% at 48C.
Temp is still climbing, but slower. Right now it’s been bouncing btwn 50 and 49 for the past 10 mins, 60% charge.
Anyone wanna try shiny-side-out aluminum foil?
A dripline onto the battery won’t work for me, too much iron in the water lol.
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Cool, that’s a real good looking $7k unit there, yarbo should be real proud of themselves, but just wait a few weeks when they come out with the core pro, which has dedicated charging pins like every other mower, and it will much better than what we have, promise!
I just don’t get it, so much talk from yarbo and whatnot they have tested and tried to bring out the best mower, seems they never testet it in warm climates under direct sunlight at all, they would have found that flaw!
Agreed that if they’d marketed this as a hobby, this stuff probably would have gone over a lot better.
Outside temp now 94, batt just flickered to 51 at 68%
Looks like, short term, a reflective surface will be pretty helpful.
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Well, here’s my temporary solution. Foam board tied to patio chairs, battery cover off and industrial fan blowing in the battery compartment. Barely holding on but stable at 49 C with ambient temp at 98 F in the hottest part of the day. SOC up to 72% still charging.
Update: I made to 80% with this configuration before I sent it back out do what what I paid $5K for. We’ll see if the battery survives the summer.
The battery is sealed in a metal box with no ventilation. That box is then dropped in another box with no ventilation. The key is to wash the thing with massive amounts of air to dissipate the heat. There’s no way this was tested in the summer conditions or this problem would have been immediately apparent.
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@Wes I did manage to charge and mow all day today. High today was 95. I was able to charge in the hottest time of the day.
I believe the prototype is a success so far.
Tomorrow’s high is forecast to be 89 but we might get some rain.
Here is today’s temperature data.
The highlighted row shows the 93 degree temp and the battery was charging in full sun with the reflectix in place. Max battery temp was 49 (120.2)
I’m going to leave it in place for the foreseeable future.
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