In our trailers and vehicles I prefer 24V 8s batteries, as the price-weight-power triangle of our Eve 280Ah cells is hard to match. With a gross weight of roughly 55kg we get a nominal “capacity” of 7168Wh. Even at a low cell voltage of 2.7V we can still get more than 2400W (3000VA) out of the battery. Exactly what a Victron MultiPlus-II 24/3000/70-32 (or any 3000VA inverter/charger for that matter) can deliver.
The Honda EU 10i has a sustained output of 900W which equates to roughly 3.9A at 230V. Now, this is not too interesting by itself.
However, the minimum AC current input of the MultiPlus is 3.6A. So, exactly within the range of the Honda EU 10i. A 5000VA inverter for example, would drain the generator with its minimum input of 4.6A+. And with its fuel tank capacity of 2.1l it runs nearly 4h on full load. Which in turn means, I can charge our 24V 8s battery about 50% without refueling.
Note: ideally we would charge it from 25% up to 75% SoC.
So, for me this generator is the ideal backup when I am away without any EV station nearby. With its 13kg and small form factor (and price) there is always a place in my vehicles where I can put it.
And as a side benefit: when I run the generator along with the inverter I can generate up to 3300W (or over 14A). That is: run my oven and boil potatoes at the same time …
And the generator even makes sense when combined with a Victron MultiPlus Compact 24/1600/40-16 (or its 12V counterpart). They are the smallest inverters/chargers in that power range. They strong enough to run a coffee machine or immersion water heater, but are not pwoerful enough to run a full 2000W appliance. However, in combination with the Honda, they just reach 2180W. Of course, charging a 24V 8s battery with a “Compact” device takes much longer, due to its smaller charger.
Along with some others I am waiting for Raspberry PIs to become available again (while *not* supporting these overpriced resellers on eBay, Amazon and elsewhere).
Luckily, back in 2016 (or was it 2015?) I bought two Raspberry PI2 Model B Rev. 1.1 with 1 GB RAM and an Edimax EW-7811Un WLAN adapter. At that time the PI did not have built-in WLAN and it was said that the original Wifi dongle Raspberry Pi WLU6331 did not work with all distributions.
We had some plans what to do with the Pi – but they never made it into reality. Instead, they went into the locker.
Edimax EW-7811Un WLAN adapter
Fast forward into the future, the whole world experiences stock supply shortages and a Raspberry Pi (now in its 4th generation) is hard to get hold of.
As I am building a couple of batteries mostly with JK-BMS I need a RS-485 connection to my Victron inverters to control charge and discharge currents. Except for the GX versions of the MultiPlus-II and EasySolar-II that _sort of_ support RS-485 (not out-of-the-box, but) in a single box, I always need an additional device like a Cerbo, BBB or: a Raspberry Pi!
But as I already wrote: I did not want to support resellers with their pharmacy pricing, so I had a look at the Venus OS compatibility list and saw that – surprisingly – even a Pi 2 is supported. So, I went looking in my shelves, lockers and other places to find these rusty old Pi 2s – and after a couple of weeks I actually found them (when I was looking for something completely different). Anyway, here they are – but only with a single GB of RAM.
Nostalgic side note: yes, there were times where I would have left out the word “only” …
I was not to sure if Venus OS would run on it. And if – how quick. It was time to find out …
Installation was straight forward: following Getting Started was all it needed. I connected the Pi to my local wired network for that purpose and makes updating and installing software much easier. At the very start I also enabled superuser and SSH access.
Note: There was a minor issue or whatever one might call it. After the install of v3.00 (via the SD card) I had the device check for an update (which at that time should not have been available). But for whatever reason, I was offered to update from v3.00 to v3.00. I did that and it worked and after that no more updates were recommended.
From then on, installing additional packages worked without an issue – but took considerably longer than on a Cerbo, Pi 4 or even the GX in the EasySolar.
One thing just seemed to be missing. Having the Pi to act as a Wifi access point (and router with DNS and DHCP). Why would I want this?
Some of my batteries are just standalone installations in a car, trailer or other machinery. And external network is not always available. And I do appreciate the comfort of wirelessly connecting to the GX – just as I am used to when using my EasySolar-II GX.
And as nearly always: I was not the first one to ask for such a feature:
After a reboot, I could successfully connect to the access point and VictronConnect immediately found the “Cerbo”:
Raspberry Pi 2 Model B Rev. 1.1 as a Victron GX device while acting as an access point
After I enabled the access point (or tether option) I could no longer see or access any other SSIDs from the Pi:
WLAN client is deactivated when running an access point
Running ifconfig gave me this output:
ifconfig output after enabling the access point
Certainly, I was interested in the performance or resource consumption of the Pi 2. As it turned out, the UI really took some CPU but the additional network services themselves were not quite as hungry: idle floats between 71% and 92%.
Pi 2 running with a RS-485 adapter and enabled access point
So, this is it. My investment of roughly 35$ in 2016 (even with intereste rate) really paid off. I have a working GX device that does everything I want – plus an access point – all in a single box.
Pi 2 running with dbus-serialbattery, BatteryAggregator and access point
Our Journey to Scotland 