Frequently Asked Questions

Frequently Asked Questions

App Questions

Can I temporarily disable Charge HQ?

Yes, in the app navigate to Charging Settings, the slide the Charging Control Enabled toggle to off. This will stop Charge HQ from sending any charging commands to your EV or wall charger.

Why is the app showing External Control Detected?

Charge HQ attempts to detect when you start or stop charging from your vehicle or the vehicle's app, eg the Tesla app. Once detected it will display the "External Control" detected banner in the app and cease control of charging. This is to prevent Charge HQ from overriding what you are trying to do in the vehicle.

External control is also detected when charging is started by the vehicle's charging scheduler, eg if you enable scheduled charging on the vehicle rather than in Charge HQ.

Charge HQ will stay in the "External Control" mode until the vehicle is unplugged or you select a different mode (Stop, Auto, Charge Now) in the Charge HQ app.

In future, we will add a notification so you can be alerted when external control is detected.

The external control detection may occasionally incorrectly detect external control. If this happens, please feel free to let us know.

Charger Questions

Which wall chargers do you support?

See the Wall Charger Support Register for a current list. Note: if you have a Tesla you can use Charge HQ with any wall charger.

Can I use a Tesla Mobile Charger?

You can, but since the charger itself cannot be remotely controlled, it can only be used with Charge HQ in combination with Tesla vehicles currently. See our list of other supported smart chargers.

Can I use a Tesla Wall Charger?

You can, but since the charger itself cannot be remotely controlled, it can only be used with Charge HQ in combination with Tesla vehicles currently. See our list of other supported smart chargers.

What is OCPP?

OCPP stands for Open Charge Point Protocol. It allows communication between EV chargers and centralised management systems such as Charge HQ. Charge HQ uses OCPP to control wall chargers where it is supported.

Do I need a wall charger?

No, as long as you have a Tesla.

If you have a Tesla then Charge HQ will work regardless of the charger you use, including the UMC charging cable that comes with the car.

If you don’t have a Tesla then you’ll need a supported smart charger to use Charge HQ.

See also our article on what speed home EV charger do I need for thoughts on why you might want a wall charger.

General Questions

How can I access the very latest features in Charge HQ?

New features are first rolled out to the web version of the app. You can access this via a browser on your mobile or desktop device at: https://app.chargehq.net/

Note: Whilst Charge HQ will work if being used both by the mobile and web apps, you may notice inconsistent behaviours on the mobile app when using new features in the web app.

Can you get my solar data from my smart meter?

To our knowledge, none of the smart meter providers offer an API with near realtime access (1-5 minute maximum delay) to the metering data. In Australia, most are delayed by 24 hours and data is provided at 15 minute intervals.

Some smart meters provide a local data interface via Zigbee and we would be open to integrating with this if we find some good hardware which makes this data accessible via an API with frequent updates.

Can the app do maximum load control?

Currently no. We may consider adding this feature in future but note that the speed it reacts will be limited by the data feeds which are typically in minutes, vs local systems which can react at the second level.

Which electricity retailer should I use with Charge HQ?

Charge HQ works with any electricity retailer both in Australia and internationally. In Australia WATTever provides some great resources to help you choose the best electricity retailer for you.

Why does solar charging stop when the Do Not Charge Price limit is exceeded?

If you are using a price source (eg Amber or AEMO spot price) and set a Do Not Charge Price limit, you may notice that solar charging is stopped when the price limit is exceeded. This may be unexpected, as you might consider solar energy to be free and that the price limit should only apply to grid imports.

However, when you consume your own solar you are forgoing the feed-in credit that you would have earned if that excess solar was fed into the grid. Thus the "price" of your own solar is actually the feed-in price at the time. For example, if the wholesale price spiked to $5 / kWh, you would effectively be paying $5 / kWh to charge your EV.

When charging from solar, Charge HQ will stop charging when the feed-in price exceeds the Do Not Charge Price.

When charging from the grid, Charge HQ will stop charging when the import price exceeds the Do Not Charge Price.

If you are charging from a mix of solar and grid using Solar+Grid mode, Charge HQ will use the import price if less than 1 kW of solar is available for charging, otherwise it will use the feed-in price.

How much will Charge HQ cost?

We are still working on possible business models and pricing options. We are determined to make Charge HQ good value for money, both in terms of the benefits it provides and in comparison to other products that do similar things.

In future we plan to enable Charge HQ users to optionally participate in programs which provide incentives for providing grid support, for example avoiding charging during peak periods or when a power station fails. The value from these programs should reduce or eliminate the costs of Charge HQ to the end user.

There are still some major features to add and other work to complete before coming out of beta, so the product will remain free to use for now.

What could go wrong?

Using Charge HQ may result in your vehicle charging when you don’t want it to, or failing to charge when you do want it to. We try hard to avoid these kinds of bugs but you should be prepared for them to happen occasionally, especially during the beta development phase.

Do I need to switch electricity retailer?

No, Charge HQ will work with any retailer.

That said, Charge HQ currently has an integration with Amber Electric. If you are an Amber customer then Charge HQ can obtain and react to your current electricity price.

Integrations with other retailers may be added in future.

Will you spam me with ads?

Nope. We hate ads too.

How is it free?

Charge HQ is currently in beta development, which means frequent changes, bugs, minimal documentation and best-effort support. We are still working on making the app as useful as possible, and are exploring possible business models to make the product sustainable.

Will you sell my details or data?

We will never sell or provide your personal information to a third party, unless required by law.

We may share anonymised and aggregated data (eg average charging profiles) to third parties or to the public if it’s consistent with our objective to support the transition to renewable energy.

Please see the privacy policy for details.

Home Battery Questions

Does Charge HQ work if I have a home battery?

Yes. Advanced integration features allow you to choose whether to prioritise home battery vs EV charging from solar.

Which home batteries do you support?

You'll find a full list of supported batteries in the Home Battery System Support Register.

If my home battery is supported, does my solar inverter need to be supported also?

No. You only need one of the two to be supported to use Charge HQ. See the Solar Data Support Register for more details.

Will my EV charge from from my home battery?

If your EV is charging from the grid overnight, and the battery has charge, it will be used. This is a common occurrence with EV chargers. There's a detailed explanation of why this happens and some workarounds in our article on EV Charging and Home Battery Interaction.

What's the best battery to use with Charge HQ?

The choice of battery impacts Charge HQ by how frequently it provides data updates. Those which update more frequently allow Charge HQ to work slightly more efficiently. See our page comparing the monitoring data update frequencies for the different solar inverters and batteries.

Solar Questions

How does Charge HQ home solar charging work?

Charge HQ uses a live data feed from one of the solar inverter, home battery or an energy monitor. This data feed is accessed over the internet and provides time series data on how much solar is being produced and in many cases how much is being exported. Charge HQ constantly monitors this data feed then communicates with the EV or wall charger over the internet, instructing it to charge at a rate matching the excess solar energy that is available. You can read more about the minimum hardware requirements, or how the charging control system works.

I have two separate solar PV systems on my roof, will this work?

In most cases, yes. Please see the Multiple Inverters article for more details:

When will you add support for my solar inverter?

We are constantly onboarding new solar inverters. The order in which they're added is roughly based on how common the inverter is and how many requests we get for support. We expect there will be a small number of inverters which we cannot integrate with for technical or commercial reasons. See our list of solar inverters which covers those currently supported, requested and unable to be supported. The best way to let us know that you want us to support your inverter is via the Feature Request form.

What's the best solar inverter to use with Charge HQ?

The choice of solar inverter impacts Charge HQ by how frequently it provides data updates. Those which update more frequently work slightly more efficiently. See our page comparing the monitoring data update frequencies for the different solar inverters. Home batteries can often provide the solar generation data also so keep this in mind.

Is my inverter supported?

See here for the list of supported inverters.

Do I need a consumption meter?

No, although the solar tracking works better with a consumption meter.

If your solar system has a consumption meter, you can see your household consumption and grid imports and exports. Without a consumption meter, you can only see solar generation.

If a consumption meter is present Charge HQ can divert the excess solar to EV charging. For example, if you turn on your oven, Charge HQ will reduce the EV charging power to avoid importing from the grid.

Without a consumption meter Charge HQ can simply adjust the EV charging power to match the solar generation. So if you turn on your oven, Charge HQ won't know and won't reduce the EV charging power. The settings do allow reserving a certain amount of solar power for household consumption.

Tesla Questions

Does Charge HQ work with all Tesla vehicles?

Yes, Charge HQ will work with all Tesla Models, including S, X, 3 and Y. More details.

Can I use another third-party service eg Teslascope or TeslaFi?

Yes, although if the other service sends any charging commands then undesirable and confusing behaviour will almost certainly result.

The developer of Charge HQ also uses TeslaFi without any trouble.

Can I still use the Tesla app?

Yes - with some limitations.

Start and Stop

You can start or stop charging using the Tesla app (or the vehicle's screen) at any time, including when the vehicle is at home. When you do this, Charge HQ will detect external control and will not control the charging again until:

  • the vehicle is unplugged and replugged, or
  • a control mode is selected in Charge HQ (eg AUTO), or
  • a scheduled "Always Charge" period begins in Charge HQ
Power (amps)

When the vehicle is at home the charging power (amps) is controlled by Charge HQ. If you change the amps using the Tesla app Charge HQ will change them back, unless:

  • charging was started using the Tesla app and Charge HQ has detected external control, or
  • the vehicle is away from home

To avoid confusion we recommend using Charge HQ in preference to the Tesla app for controlling the charging.

Will it stop my Tesla from sleeping?

No. Third-party apps such as Charge HQ do not prevent Tesla vehicles from entering the low-power sleep mode.

In the past, third-party apps such as Charge HQ could prevent the vehicle from falling asleep, however recent software changes from Tesla (around Dec 2021) appear to have eliminated this issue. It is possible that some older vehicles may still suffer from this issue, which is why Charge HQ has logic to allow vehicles to go to sleep.

This TeslaFi article contains more details on the sleep situation with older vehicles.


Is it safe to give Charge HQ access to my Tesla?

Charge HQ does not have access to your Tesla username or password. You login directly to tesla.com and Charge HQ obtains a “token” which grants access to the API. Charge HQ stores this token. You can revoke this token at any time by changing your password on tesla.com.

We take security seriously and apply standard best-practices to system security. The tokens are stored in an encrypted format.

Of course, there are still risks. There is a slim possibility that an attacker could obtain the access tokens (although it would be very difficult to do so) and start sending commands to the vehicle, until the token was revoked. All third-party services which use the Tesla API involve this risk.

How does Charge HQ control my Tesla charging?

Charge HQ connects to the Tesla API, which is the same API used by the official Tesla app. This API allows visibility and control over a Tesla vehicle. There are many other third-party apps which use the same method, including Teslascope and TeslaFi.

Tesla does not support or endorse third-party access to its API. Tesla may break or disable such access at any time.

Vehicle Questions

Can I use Charge HQ with two EVs?

Support for multiple Tesla vehicles is currently somewhat limited. It works as follows:

  • Charge HQ can only control one vehicle at once.
  • You can switch between vehicles manually on the home screen. Automatic switching of vehicles is not currently supported.
  • If multiple vehicles are charging at once, solar tracking can be active on the selected vehicle. The other vehicle will charge at a fixed rate which you set using the Tesla app or the vehicle. The first vehicle's charging power will be adjusted to take whatever excess solar is left.

We are planning to improve features for those with multiple vehicles.

Will using Charge HQ damage my vehicle's battery?

As far as we know, starting and stopping or varying the charging power does not harm a vehicle's battery. There are many solar charging products on the market which perform a similar function.

We are aware of rare cases where frequent stopping and starting of charging has lead to premature failure of the contactors (switches) in the charger (not the car). Charge HQ has several delay mechanisms to limit the frequency of stopping and starting eg on partly cloudy days.

Please see the bottom of the Solar Tracking Settings page for more information.