M116A3 Build

[bdosborn]

BYW, the Mopeka Water Sensor shipped so I should have it in a week. I'll let you know how it works.
Bruce

[lfhoward]

BYW, the Mopeka Water Sensor shipped so I should have it in a week. I'll let you know how it works.
Bruce

The VRM treats it exactly the same as the RuuviTags. Setup will be similar.

[lfhoward]

Note to self,

If doing an online update to firmware of Victron devices through the VRM, those Victron devices will attempt to restart. In that case, the Raspberry Pi that connects them to the VRM, which gets its power from the load output of one of the Victron chargers, will also lose power. Thus, you will lose contact with your whole system and the VRM will not update the charge controller's firmware.

...

I will have to visit the system in person tomorrow to get everything back working and online. LOL.

This was unexpected because I don't remember the Raspberry Pi ever losing power when doing a firmware update to the solar charge controller via Bluetooth from my phone. Looks like that's how I'll be doing it from now on.

[lfhoward]

Back online after updating the firmware via bluetooth in person.

Looks like if I want to be able to update firmware via VRM I need to move the Raspberry Pi circuit to the main fuse panel rather than have it come from the load output of the solar charge controller, so battery power remains uninterrupted during the update. I don't think I will do that because I don't have a spare circuit in my fuse panel, but I thought I'd mention it in case anyone else is reading this and designing their Victron system.

[bdosborn]

Looks like if I want to be able to update firmware via VRM I need to move the Raspberry Pi circuit to the main fuse panel rather than have it come from the load output of the solar charge controller...

I had to move my Cerbo GX to an unswitched source, you should too if you're using DVCC. My PV charge profile went wonky when my Cerbo GX was switched off.

I got the Mopeka water sensor installed, easy peasy and it looks like its much more accurate than the pressure sensor I'm using.

Bruce

[lfhoward]

Did a camping trip to Vermont this weekend! We arrived to our campground just as the rain moved in.



The next morning though was really beautiful. And the coffee hit the spot.



The campground had a little pond, which we parked right next to.



The next day I met up with some colleagues and friends for a hike up “The Dome”.



Beautiful scenery ensued.

[bdosborn]

Nice, its a great time of year to camp.
Bruce

[lfhoward]

The December bomb cyclone of 2022 is hitting today, with temperatures dropping from 57°F to 6°F in under 12 hours. Check out the barometric pressure from the last 7 days, just falling off a cliff this morning:



Although the outside temperature is 23°F as I write this, the battery is down to 45°F as there is a lag due to insulation and battery density. I have the battery heater thermostat programmed to be on everyday from 6 am to 12 pm, with the beehive heaters under the battery energized at 39°F°. It will be interesting to track the battery temperature tomorrow morning. Solar charging can still happen if I keep the battery warm enough (39° or higher). It has worked fine through 2 winters now, but this storm will produce the lowest temperatures yet seen for my battery setup.

[featherliteCT1]

Good info to know. I look forward to your next update.

I see where bdosborn put a moving blanket over his battery in his van to see if that helps any. Looking forward to his next report too.

[bdosborn]

We got down to -14 f so I've been running heater tests with some interesting results. I'll post info and graphs after Christmas.
Bruce

[lfhoward]

Reporting in. Nights have been down in the single digits and the battery temperature has been down in the teens by morning for the last few days. The battery heater kicks on and warms it up to 45°over the course of about 3 hours. I tweaked my program to turn the battery thermostat on at 5 am so the battery is up to temperature and ready to absorb some electrons when the sun comes out. Where I have the trailer parked I really only have direct sun until noon, so each day of this arctic blast the trailer has been losing ground. The battery started out at about 80% before the extreme cold weather several days ago and is going to top out at 65% today. Running the battery heater and solar charging results in losing less ground than not running the heater or charging at all, so I am ok spending the power on it every morning. The power draw is 8 watts including raspberry pi computers plus the Victron equipment. Probably 5-6 watts of that is the pi’s.

When the weather warms up next week the trailer will be able to make a net power gain again and begin filling the batteries. It had been about a month since it has seen a full charge. Depending on how low the batteries get this week I may either plug in the 120VAC charger or move the trailer to a better spot that gets more sunlight.

Amp hours over the week (156 Ah capacity)


Temperatures over the week (red = battery, green = outdoor, blue = indoor)

[featherliteCT1]

That is some great data. Thanks for posting and explaining.

[bdosborn]

Here's my results:

I've got my 4x12W=48W battery heaters setup to come on at 34F and turn off at 36F. I covered the battery with a moving blanket to try and insulate it a little better. I turned the heaters on Wednesday the 22nd and turned them off when we got home today the 26th. The heaters kept the battery warm down to -8F in the van (it was -15F outside).


Running the heaters costs around 10% of my battery capacity per day (40 A-Hrs/day).


I turned on the inverter/charger right when the cold wave hit but was running completely on battery the 23, 24 and 25th. Just the PV panels will keep up with the usage if I'm parked in full sun and it's fairly sunny. I was parked at my brother-in-laws house for Christmas and his driveway gets full sun all day. Our driveway only gets full sun till noon or so this time of year. So I'm not comfortable leaving the battery heater on all the time without being plugged into shore power, but its pretty close.

Here's what I concluded from the tests:
- I'm glad I used the bee heaters, they don't get too hot. Some of those Amazon silicone heating pads get way too hot.
- I'm going to bump the on/off temperature up a degree for a little bit more of a safety margin.
- I'm going to ask my wife to make a battery cozy out of thinsulate, I bet that heaters will run less with the better insulation.

lfhoward thanks for posting your results, I'm glad to see you had good luck with the heaters too. Its harder than people think to be your own power company.
Bruce

[lfhoward]

Bruce, thanks for posting your results too. Super interesting to see another setup using beehive battery heaters.

The long term problem I’ve been having is that since mid-November the trailer battery has not been able to get back to full. The short days and cold temperatures have been slowly chipping away at the bottom line, such that last night the battery was in the 40’s % range. It has been parked in a suboptimal place from the sun standpoint, getting only about 3 hours of direct sun. I moved the trailer today to a new place where it can get 5-1/2 hours of direct sun, and faces more to the south. I’ve had the solar panel angled up to get the most photons since October. This new parking spot worked well last winter, so it will be interesting to see how long it takes for the battery to top back off to 100%. We have a string of cloudy days coming up, so I expect that it will be more than a week away.

[bdosborn]

Bruce, thanks for posting your results too. Super interesting to see another setup using beehive battery heaters.

I see Facebook posts of guys living in their vans his time of year and I don't know how they keep up with their energy use. They've got to be in open spaces with full sun all day long. I guess I'd be looking at tilting my panels if I was living in my van.
Bruce