We recently received an interesting suggestion from a customer in Europe, and we would like to hear more feedback from the community.

In many parts of Europe, utility smart meters expose import/export data through the P1 port. Many home batteries rely on a separate plug-in P1 meter to read this data and decide when to charge or discharge.

The customer pointed out that these P1-based meters often have relatively low update frequency and noticeable delay. Compared with them, IAMMETER meters can provide faster and more responsive data updates.

The idea is simple: if IAMMETER could provide a P1 adaptor that makes an IAMMETER meter behave like a P1 device, then users could send real-time grid import/export data directly from IAMMETER to a home battery, without adding a second smart meter.

In this specific case, the customer is already using WEM3080 together with WPC3700, and is now planning to add a Marstek Venus E battery. The request is to let the battery get its energy data from IAMMETER instead of from a separate P1 meter with a slower refresh interval.

We Are Evaluating This Idea

IAMMETER is now evaluating a possible P1 adaptor for integration with home batteries and other energy management devices that expect a P1 interface.

At this stage, we are especially interested in practical design suggestions from users, installers, and battery owners.

Questions We Would Like Your Feedback On

• How should the P1 adaptor be powered?
• Should it draw power from the grid side?
• Should it be powered from the battery side?
• Would a simple USB power input be the best option?
• Which battery brands or systems should we prioritize first?
• What refresh rate, installation style, or connector format would you expect?

Rewards for Useful Feedback

Users who provide useful design suggestions may receive:

• IAMMETER reward points. See the Contribution Guide.
• A chance to join the free trial program for the future P1 adaptor.

Yes that would be nice, i have a normal p1 meter at the momemt and a marstek battery venus A system, but if i want to see my battery seperate on the iammeter app do i need to buy another meter from aimmeter i assume ? Because i have already 2 meters  too measure the amount of sun i collected, and the amount of energy i take of the grid/net.  Hope to get a nice response

Hi,

Yes, if you want to see the Marstek Venus A battery separately in IAMMETER, the key point is that the battery charging/discharging power needs to be measured separately.

As far as we understand, the Marstek Venus A is an AC-coupled battery system, so it works as a separate AC device rather than a DC battery directly connected inside the PV inverter. Therefore, the most direct way is to measure the AC line of the battery.

Could you please help confirm a few details about your current system?

1. Is your grid connection single-phase or three-phase?
2. Is your solar inverter single-phase or three-phase?
3. Are both of your IAMMETER meters three-phase meters?
4. Are all three channels/phases of both IAMMETER meters already used now? For example, what are phase A/B/C of each meter currently measuring?

If one channel of an existing three-phase IAMMETER meter is still unused, it may be possible to use that spare channel to test or monitor the charging/discharging power of the Marstek battery, without buying another meter immediately.

Also, could you please confirm what your P1 meter is currently used for? If it is already reading the grid import/export data, there may be another possible solution. If the P1 meter is ESP32-based or can be programmed to send data through HTTP/API, it may be possible to upload the P1 grid data to IAMMETER-Cloud as a Virtual Meter. Then the IAMMETER meter currently used for grid monitoring could potentially be reused to monitor the battery AC line.

This would require some DIY/development work, so it may not be the simplest solution, but it could be a useful option if you want to make full use of the meters you already have.

Another possible option is Home Assistant. I am not sure whether the Marstek Venus A has an official Home Assistant integration, but if your battery data is already available in Home Assistant, such as battery charging power, discharging power, charging energy, and discharging energy, you may also consider uploading these Home Assistant sensor values to IAMMETER-Cloud through a Virtual Meter.

You can refer to this method here:
https://www.iammeter.com/blog/connect-home-assistant-energy-devices-to-iammeter-cloud

So in summary, the possible options are:

1. If there is a spare channel on your existing IAMMETER three-phase meter, use it to monitor the battery AC line.
2. If all channels are already used, add another IAMMETER meter to monitor the battery separately.
3. If your P1 meter can upload grid data to IAMMETER-Cloud as a Virtual Meter, you may be able to free one IAMMETER meter for battery monitoring.
4. If the Marstek battery data is already available in Home Assistant, you may also upload that data to IAMMETER-Cloud via a Virtual Meter.

Please let us know your current wiring and how the two IAMMETER meters are being used now, then we can suggest the most suitable option.