M116A3 Build

[bdosborn]

More to come on this because I haven’t given up. Has anyone here had success setting this up? (Bruce, have you tried this with yours?)

No, I went a different route with my BMS, I'm using an Electrodacus SBMS0. It has a WiFi module that reports battery cell status and has charge/load control relays that make it easy to control Victron components:



Bruce

P.S. You should go into the remote console->settings->DVCC and poke around (if you haven't yet). I just stumbled across it recently, it shares V and I sensor values across Victron components.

[lfhoward]

Thanks for the reply, Bruce. I noticed that the dbus-serial battery instructions say to turn on DVCC but I didn’t understand what it was for. Looks like I have some reading to do.

[lfhoward]

The M116A3 hasn’t moved at all for many months. I’m planning a trip in May, and can’t wait to get out there again.

One of my favorite things about the new electrical system is that I can keep tabs on it using Victron’s VRM system. This is what a typical sunny day looks like as the trailer hangs out.



You can see the solar/battery monitoring system with the 2 Raspberry Pi’s and Victron equipment uses about 7 amp hours overnight, which is promptly replaced as soon as the sun comes up. With a 156 amp hour battery, 7 amp hours = only 4.5%.

The parameters of the charging system are set up so that the battery maxes out at 13.8 volts, stays there for about 15-20 minutes in case any cell balancing is needed, then floats for the rest of the day at 13.4 volts. These levels keep the voltage out of the steep section of the charge curve, hopefully extending battery life for many additional years. (Even not being conservative, these LiFePO4 batteries are rated for 2000-4000 cycles at 100% power use, or 5.5-11 years at 1 full cycle per day!)

I just thought anyone considering installing the Raspberry Pi’s and setting up the VRM might want to see what kind of power use was required.

[lfhoward]

The M116A3 trailer passed its annual State of PA inspection today. No issues. Chassis greased, DOT-5 brake fluid topped off. The squeaks are gone as she goes down the road and stopping works well, as it should.

Adding up our longer trips over the last year, I think we went somewhere between 8-10,000 miles with this trailer.

[featherliteCT1]

lfhoward,

I just finished top balancing my newly acquired Lifepo4 EVE LF280k AH cells configured into a 4S battery pack with the Overkill BMS. Following your build gave me the "courage" to do so. So far, so good!

Eventually, I hope to learn how to set up a Raspberry Pi with a VRM like you have done. At this stage of my development, I only vaguely understand what that means, but I do like the graphs you post!

[lfhoward]

lfhoward,

I just finished top balancing my newly acquired Lifepo4 EVE LF280k AH cells configured into a 4S battery pack with the Overkill BMS. Following your build gave me the "courage" to do so. So far, so good!

Eventually, I hope to learn how to set up a Raspberry Pi with a VRM like you have done. At this stage of my development, I only vaguely understand what that means, but I do like the graphs you post!

Bravo! Good on you for setting up a 280 Ah LiFePO4 battery! That’s awesome. You will never be hurting for power in your trailer ever again.

If you need any advice/help setting up the VRM on a Raspberry Pi microcomputer, I’m happy to lend a hand. Do you have a Victron solar charge controller or BMV battery monitor in your trailer? The Pi/VRM can talk to both of them (and to most Victron devices) so you can see your battery status remotely.

[lfhoward]

Victron’s Venus OS 2.90 just came out, and now I have a couple of cool features on the VRM besides the state of charge info for solar and battery.



I have a couple of RuuviTags communicating the interior and exterior temperature with the VRM, as well as a Mopeka LPG tank sensor that tells me the percent of propane I have left. I just think these little bluetooth sensors are super cool, and good on Victron for working with each company to make their stuff compatible.

Here’s a recent 24 hour period showing outdoor (green) and indoor (blue) temperature changes throughout the day. Temperatures slowly declined overnight, then increased when the sun came out the next morning. Then a cold front moved in at about noon and it rained heavily when the green line dropped off. The sensors will also report percent humidity and barometric pressure (not shown on this graph but you can see that on the VRM dashboard above).



And here is a recent picture from a camping trip in Vermont this summer. Got to put in pics of the trailer every so often to remind myself and others what it looks like!



We are planning some fall and winter trips for this year, so the temperature sensors and propane sensor will come in handy for sure.

[featherliteCT1]

I love the way you are able to monitor all your systems. Very cool!

[lfhoward]

I love the way you are able to monitor all your systems. Very cool!

Thank you, me too!

I am a bit of a science nerd, so figuring out how to do this stuff is both challenging and fun.

[bdosborn]

Just checked and the Cerbo GX is on 2.90, looks like it Auto updated. The Raspberry Pi is still on 2.89 and says there aren't any updates available. Did you have to do a manual update via an SD card or did you update online?

Bruce

P.S. how did you show multiple temps on a single graph? I need some of that action!

[lfhoward]

Just checked and the Cerbo GX is on 2.90, looks like it Auto updated. The Raspberry Pi is still on 2.89 and says there aren't any updates available. Did you have to do a manual update via an SD card or did you update online?

Bruce

P.S. how did you show multiple temps on a single graph? I need some of that action!

Hi Bruce! 2.90 requires a reflash of the SD card for the RPi, as this version will not update over the air. You could try the .swu update file on a USB thumb drive first, but I went right to the reflash using the wic.gz file. Then I set it up again from scratch.
You can download the latest for your Pi4 here:
http://updates.victronenergy.com/feeds/venus/release/images/raspberrypi4/
Or for your Pi3/3b/2b here:
http://updates.victronenergy.com/feeds/venus/release/images/raspberrypi2/

The 2 Temps on one graph was from the VRM’s option to make custom widgets. It’s under Advanced & widget settings. I think it is a recent feature that came out with 2.89 in June if I remember correctly.

[bdosborn]

Cool, thanks for the 411. Victron has got to include a backup for the Venus settings, it's a PITA to reconfigure everything after an update.

Bruce

[lfhoward]

Cool, thanks for the 411. Victron has got to include a backup for the Venus settings, it's a PITA to reconfigure everything after an update.

Bruce

It’s true. I went back to Off Grid Garage’s videos to re-add the shutdown command to the menu. Still works.

Raised the angle of the solar panel today.

[bdosborn]

I didn't build any tilt into my panels and I only run the two 100 watt panels in the rear when the van is parked at home.

It will be interesting to see if they keep up during the winter, I might have to add some tilt if they don't. The Victron Multiplus inverter maintains the start battery so I haven't had to plug the van in since I installed the panels. I'd kind of like to keep it that way.
Bruce

[lfhoward]

I didn't build any tilt into my panels and I only run the two 100 watt panels in the rear when the van is parked at home.

It will be interesting to see if they keep up during the winter, I might have to add some tilt if they don't. The Victron Multiplus inverter maintains the start battery so I haven't had to plug the van in since I installed the panels. I'd kind of like to keep it that way.
Bruce

The panels on your van roof look like they were made to go there! Nice fit. My one panel is 210 watts so basically comparable to your 2 smaller panels together. It does fine keeping the battery topped off in the winter, even replacing the amp hours used by the battery heating pads. I’ll have to see how it goes when things get really cold and the sun is low in the sky, because last year I needed to change parking lots to get a better southerly aspect. However, this year I have a better program I wrote to control the battery heater on/off times, so the trailer might be able to stay where it is. It gets full sun between 8:30 and 12:30 now, more like 9 and noon in the dead of winter. And where it is parked now is more of an easterly aspect.

Comparing yesterday and today, both clear sunny days, the battery reached full capacity at 10:07 yesterday and 9:23 today. Both times, the panel was charging up 8 amp hours consumed overnight by the electronics in the trailer. The only difference was tilting the panel. It is at 23° now and could go higher if I need. Since I am sitting at 40°N latitude, I imagine that angle will work best in mid December.