Intelligent charging extends the service life of the MyReserve

3,000 kWh additional storage capacity thanks to self-learning software

Many users believe that once excess solar power is available; a storage battery should charge fully as early and as quickly as possible. This approach sounds plausible, but has a decisive disadvantage: a 100 % charge means very high "chemical stress" for the battery cells. This means that the battery ages much faster in the fully charged state than at lower states of charge. MyReserve's strategy is to charge the battery as efficiently and gently as possible.

Typical home batteries start charging early in the day, as soon as excess solar power is available. They usually reach a full charge in the morning and then remain in this maximum charge state all day long. The cells age much faster than they otherwise would which drastically reduces both the service life of the battery and its long-term benefit to the end-user.

MyReserve operates according to a different charging strategy. The battery is designed to reach the 100 % state of charge shortly before sunset so that time spent in this state is as short as possible. It does not matter when the battery is full – so long as the power you need is there when you need it, and this is typically in the evening once the sun has gone down. However, when the battery is full is very decisive for the service life of the battery and MyReserve is designed to function far longer than the competition!

Battery or accumulator?

Originally, non-rechargeable storage devices for electrical energy were called batteries ("primary cells" or "primary elements"), while rechargeable storage devices ("secondary cells" or "secondary elements") were called accumulators. These terms have blurred in meaning over the years, the most prominent example being the "car battery", which was originally constructed as an accumulator.

On closer inspection, the MyReserve device is a lithium-ion accumulator, but it usually referred to as a lithium-ion battery.

Intelligent charging strategy of MyReserve

 

The strategy:

The self-learning software analyses solar power generation and consumption from the past several days. It schedules the battery to charge itself over the whole day such that it spends the shortest time possible in a fully charged state. Full capacity is available in the evening when the sun is no longer shining.

The result:

Aging due to chemical stress is avoided which results in 3,000 kWh extra energy stored by the battery over its entire lifetime.

All figures refer to a MyReserve with 7.2 kWh capacity in a typical home. Calculated over the entire lifetime.

Battery with self-learning algorithm

MyReserve uses a self-learning algorithm that adapts to the individual conditions in the house. The battery "learns" what solar radiation (i.e. yield) is throughout the day and the electricity consumption patterns of the household. Based on data from the previous seven days, the battery optimizes its charging behavior. The algorithm uses all available empirical values to draw up a forecast for the optimal charging schedule. If there are drastic deviations from the learned behavior, this strategy is automatically adjusted.

ideal charging process

Example of ideal charging process:

The battery starts charging at a pre-calculated point in time and reaches 100 % charge shortly before sunset.

Longer service life, more power

MyReserve has its own weather measurement station and uses the current solar radiation, temperature, and weather to predict the amount of electricity the solar panels will generate, location-specifically and precisely. Weather conditions and thus radiation intensity and radiation duration often remain stable over longer periods, i.e. the conditions from previous days can be used with some certainty to determine the current day. Surprising, drastic changes in the weather, e.g. a bad weather front, can influence the charge of the battery. The battery management system "learns" from such events and adjusts its charging strategy for the future. Overall, this procedure ensures the maximum service life for the MyReserve, which means 3,000 kWh more solar power stored for your usage! This significantly reduces the cost per stored kWh compared to other batteries.

Why do lithium-ion batteries "age"?

All batteries "age" over time, i.e. they become less efficient. This is caused by changes in the cell’s electrodes due to chemical processes. This aging process is, among other things, accelerated by a high state of charge.

MyReserve: Grid-supporting storage contributes to the energy revolution

In addition to the increased service life of the MyReserve battery, there is another argument in favor of this intelligent charging strategy: The battery behaves in a grid-supporting manner. What does this mean? While MyReserve can still absorb energy during the midday peak, conventional batteries are typically already full and all excess solar energy feeds directly into the grid. Therefore, the advantage of using batteries to relieve the grid and reduce the need for grid expansion is only true of batteries with an intelligent charging strategy. By opting for MyReserve, you are helping to stabilize the grid today and support the success of the energy revolution.