Bluetti now offers a vast range of solar generators, ranging from 300Wh to 5100Wh.
If you have recently purchased one of our products and used it to run some of your latest electronic appliances, you may have noticed that now and then, your solar generator just turns off.
If you are experiencing this problem, the question you are bound to have is: Why does my Bluetti solar generator keep turning off?
Each of our generators have a built in pure sine wave inverter. If the load you run through your solar generator is too large for the rated power output (e.g you connect a 500 watt power tool to your 300 watt solar generator), your inverter will automatically shut down the power for safety reasons.
In order to avoid this from happening, you will need to carefully match your energy demands with the rated power output of your Bluetti Solar generator.
This is why all our solar generators come marked with their total power output and watt hours storage capacity.
In this article we will explain just how an inverter works so that you will know how to troubleshoot the next time your solar generator turns off.
Why does my Bluetti solar generator turn off?
In order to understand how to fix this issue, you need to understand why this problem originates in the first place.
The reason your solar generator may turn off when you run some of your appliances through it, is most likely due to the built in pure sine wave inverters safety feature.
First, we will break down each of the components that make up your solar generator then we will explain what each one does.
Battery
Every solar generator comes with a battery, it is essentially the life blood behind the technology and without it, your solar generator would not be able to store electricity for future use.
The type of battery that comes with your generator varies depending on the brand you choose. Bluetti only uses the latest lithium ion battery technology, which is most well known for its great life span.
Charge controller
Charge controllers have two main functions: regulate the power output of your solar panel and to properly charge the battery.
On the market today there two types of solar charge controllers: the PWM (Pulse Width Modulation) and the more efficient MPPT (Maximum Power Point Tracking). Bluetti uses MPPT charge controllers in their products.
Inverter
Now for the most likely reason your solar generator keeps turning off. Inverters convert DC (direct current) electricity to AC (alternating current) electricity.
An inverter is needed because your solar batteries will store DC, and most of the appliances around your home, van, cabin or boat will require AC in order to operate.
You have a few options when deciding on an inverter, the two most popular being the pure sine wave and modified wave inverter. Bluetti uses the pure sine wave inverter in their solar generators.
How does a pure sine wave inverter work?
Sine wave inverters, like the pure sine wave inverter we use in our solar generators work in 3 stages: the oscillator stage, the booster stage or amplifier stage and the transformer stage.
The oscillator stage
Here the direct current is transformed into alternating current. The oscillating current can be set to any particular frequency that you fancy. In Europe for example the frequency is 50 Hz.
This means there are 50 full waves per second. The direct current is transformed into alternating current by using integrated circuits.
However it is important to note that in this stage the oscillations or wave heights are somewhat small, too small in fact to power anything useful. To power bigger appliances, the wave heights need to be increased. This is where the next stage comes in.
The booster stage
In this stage the signal from the oscillator stage is taken and amplified. By doing so, much higher wave forms with greater wave heights are created, enough for useful power.
However, there is one thing left in order to allow the electricity to power home or business appliances: the voltage.
The transformer stage
This stage is what gets the voltage right. Your typical residential solar system array may have DC voltages of up to 600V.
Commercial solar arrays have even higher voltages, sometimes up to 1000V or even higher! In Europe AC power is delivered at 230V whereas in the US it is delivered at 110V.
The stability of this voltage is of the utmost importance for the stability of the grid and any equipment that runs of the grid (or in this case, solar generator). This is why voltage control is last important step of a pure sine wave inverter.
Understanding how much load my solar generator can handle
Now that you have a better idea on how exactly an inverter works, one should naturally move onto the next point. How much load can my solar generators inverter handle?
You will notice that we list our solar generators in the following format: [model name | battery capacity | inverter watts ].
Understanding the sort of load your solar generator is capable of handling is paramount to understanding why it may turn off sometimes.
If you ever run an appliance that exceeds your solar generators wattage capacity, the built in pure sine wave inverter will shut your machine off.
Understanding your Bluetti solar generators load ability
(1) 12V / 25A, 12V / 3A, cigarette lighter port, USB and type C output ports are usually quite suitable for most electronic products on the market. However, some types of products are capable of triggering your solar generators overcurrent protection if there is a large current impact at the moment of starting.
(2) The rating of your electrical products used for alternating current outputs should always be less than your solar generators wattage rating. However, do keep in mind that some electronic products such as a power tool or air conditioner may require more than your solar generators wattage rating when starting. This will trigger overcurrent protection when the ratio of peak value of rated current exceeds 3:1.
(3) When your solar generators output is overloaded, over-current or short circuited, the product will turn off the corresponding output. After doing so it will automatically start twice (at an interval of 20s). If your solar generator is overloaded, over-current or short circuited, the output will be shutoff entirely and will need manual troubleshooting to restart.
(4) Once your solar generators battery power has been discharged to 0%, the DC and AC output will automatically turn off. Only once you recharge your device to above 5% capacity will it turn the DC and AC outputs back on. This feature has been set in place to protect the battery and enhance its cycle life.
What can damage an inverter?
Capacitor wear
The first reason your solar generators inverter may begin to fail is due to electro-mechanical wear on its capacitors. All inverters rely a lot on capacitors to provide a smooth power output at various levels of current. However, like most things in life, electrolytic capacitors have a limited lifespan.
Besides lifespan, capacitors are extremely sensitive to heat. Any temperatures that exceed the stated operating temperatures will (often caused by high current) will reduce the overall life span of the component.
Overuse
Using a solar generator with a built in inverter that has been used beyond their operating limit, can contribute to inverter bridge failure.
In fact using any component past its operating limit will inevitably lead to failure. Avoiding this issue is as checking that all inverters are being run correctly.
Over- and under-voltage
The next two issues that can cause your solar generators inverter to fail is over-current and over-voltage. If at any time there is a current or voltage increase (to a level that the inverter is not made for), it can cause irrevocable damage to many of the components inside the device. The most frequently damaged component being the inverter bridge.
It is often that this damage is caused by the excess heat that over current or over voltage will generate. Most over-current can be avoided with fuses or circuit breakers (which Bluetti products are equipped with).
Conclusion
Bluetti's solar generators come with the latest solar technology on the market. That is MPPT charge controllers lithium-ion batteries and a pure sine wave inverter.
Some of these components are somewhat complex, therefore we recommend getting familiar with each component individually in order to better understand your solar generator as a whole.
Over the coming weeks, we will release shorter individual guides, that will cover the basics on how each of these components work. If you would like to learn about the components that run a Bluetti solar generator, you can do so by following this blog or our join our Quora community here.
In summary
The main reason your solar generator is shutting off, could be due to the maximum power output being exceeded past its capabilities. That is, you are running appliances (loads) with wattages that exceed the maximum power output of your solar generators built in inverter.
