Louisvdw

The latest version of the driver now include support for many more BMS. LLT/JBD / Daly Smart / ANT / JKBMS / Heltec You can find more details at https://github.com/Louisvdw/dbus-serialbattery

A bunch of us is doing a group by. PM me for the details if you are interested.

No this will not work well for you. With 2 panels your 102.98V gives you 51.5V per panel and with 3 panels this will be 154.5V (will be even higher in winter). That is a bit too much over your limit. Your MPPT will shut down too much and you will loose production. I suggest you stay with 2 panels.

You loose very little. We are talking <5% so it is not worth buying an extra MPPT. I have a MPPT where the one string face East and the other string West and this works great. All panels on the same string have to face the same direction though. A assume this is 2S4P (4 strings of 2 panels in each string). You should be able to do 3 panels in each string (check your panel's spec for the Vmax). On paper your Vmax (the open circuit one) might be more than 50V which would limit your strings to 2 panels only, but in practice here in SA it is never so cold that you will get to that value. If you have been running your current install for more that 1 year you would have done a typical winter. So go check the stats on your MPPT in the Remote Console. Under Overall History you will see what the very max Voltage is your MPPT ever reached. If for 2 panels per string this is < 100V with some margin I will say it is safe to add a third panel to each string to get closer to the 150V Here is my 100/20's history with 2x 425W panels per string. The best thing is that even if you did go over the max for a little bit, your Victron SmartSolar has over voltage protection and will not break anything, but just shut down safely until the overvoltage has cleared. This is not true for all other manufacturer's MPPT though.

Hi @smurfdbn I'm currently still busy adding support for the Daly BMS (and hopefully some others there after) so the current version will not work for you yet. The rest of your setup will be fine for this driver. If you want to help with the beta test for the Daly then I suggest you subscribe to the Daly issue to get notifications, or subscribe to the support forum (link in the Readme)

That is a good question. You can use any version (3V or 5V) as this is not used. The cable's circuit is powered by the USB and the Voltage pin of the cable is only if the other side needs power (if you have your own circuit for instance). As the other side is the BMS and it is powered from your battery cells, it does not use external power. For this reason you only connect the Ground, Rx & Tx pins. (see Installation point 2. in the docs)

The latest build V0.3 of the driver has been released. With the new version the driver will automatically set your battery max voltage according to the amount of cells in your battery, so it will work out of the box for 4 cells (12V), 8 cells 24V or 15 or 16 cells for 48V setups (or anything in between if your BMS can handle it. it also has an auto installer that works with a USB flash drive/SD card which means you don’t need root access anymore. https://github.com/Louisvdw/dbus-serialbattery

No. Sorry. It run ons the Victron system. The Axpert does not have a control system other that it's internal firmware so that won't work.

If you are using a Victron system, then go check out my BMS battery driver.

If you don't set the MPPT to limit the charge to 50A then the BMS will trip each time you go over the 50A.

If you are on a Victron system you can also try my serial driver if you want. No Arduino required. Only a serial USB connector for your battery. The Daly does have a few changes to the commands than my battery. https://github.com/Louisvdw/dbus-serialbattery

Some threads to read

If you do go the DIY option, I would suggest you look at a BMS that do have some sort of communication options (the normal Daly does not, but they do have a Smart Daly version. Or the ANT, or Smart LTT/DJB BMS). If you do have comms then there is always the option to link it to your inverter in some way like the driver I did for the Victron system. https://github.com/Louisvdw/dbus-serialbattery

No, the study is about the impact of a mix on a single MPPT.

There was a study done that show only a 1% reduction for east/west panels. In my set up I see almost no reduction. It just adds and works very well.