Force Charging with a Solax Inverter and Battery
I’ve had someone ask how to set things up so that their Solax Battery will force charge from cheap rate electricity overnight. So, rather than just reply to their question I thought I’d post a quick instructional blog post here with step by step instructions.
The Solax App
So, we generally do this using the Solax app on our phones as this is easier than doing it on the inverter itself and it can be done remotely from anywhere with internet access too. Handy if we are away and realise that we need to change some settings (usually that’s if its sunny and we forgot to turn Force charging off!)
Step by Step instructions
1. Login to your app. Here you can see the current status of your system and where the energy is flowing In this case the panels are generating 1491W, the battery is at 18% charge but is receiving 1013W of power so is being charged up from the solar panels. The house is using 430W. The 6w coming from the grid can pretty much be ignored, it’s just that sometimes there is a small surplus or deficit in the system that has to come from or go somewhere.
2. Click on the Inverter button shown at the bottom of the screen This takes you to some info about the inverter itself.
3. Click on the little gear icon at the top of the screen. This takes you to the inverter settings page.
4. Click on the Basic Settings option. This take you to a screen where you can adjust some settings.
5. Click on the Work Mode option. This brings up a drop-down menu where you can select between the following work modes: Self Use, Force Time Use, Backup Mode, Feed-in Priority. I’ll briefly explain these.
- Self Use will charge the battery when there is excess solar and then you’ll use the energy stored in the battery to power the demands of the house when there isn’t enough solar power to do so. If there isn’t enough solar power and the battery has drained to 10% then you’ll use power from the grid. This is the mode we have set most of the time in the summer.
- Force Time Use allows you to set up some parameters that will charge the battery from the grid at certain times of the day. You can set the times of the day and the amount you want to charge. More on this in a minute. This is the mode we have on during the winter.
- Backup Mode means that the battery will be charged from excess solar and will charge according to a schedule from the grid but will never discharge while the grid is live. This is so that the battery can act as a backup supply should there be a power cut. It’s unlikely that you’ll be using this option in the UK.
- Feed-in Priority allows you to send excess solar power to the grid rather than the battery – worthwhile if you have an export tarrif that pays more than the import costs but otherwise it seems more economical to charge the battery first.
6. After Selecting Force Time Use you have to click the Save button. This will then bring up more options that allow you to set the times you want to force charge. You can select two different times if you wish. We just have a single Force Charge window that schedules a charge between 1:55am and 8:30am which currently corresponds to our Economy 7 off-peak rate window.
7. First ‘Enable’ the Charge from Grid option
8. Set the start and end times of the charge (as we only have a single period of charging we have set the same times in both charge period 1 and charge period 2).
9. Set the Max Capacity that you would like to charge the battery to. At the moment we have this set to 40% which means should we wish to force charge a little when we are expecting a dull summer day we can do so. In the winter we would have this set to 100% so as to make the most of shifting to cheap rate electricity.
It’s all fairly straight forward once you know how to do it and it is easy to turn on or off force charging or to adjust the settings whenever and wherever you want via the Solax App. You can do all of this via the inverter itself and the menus are pretty much the same, but it’s easier to navigate via the app.