The Kempower S-Series Fast Charging System Is Amazing

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Originally published (not in English) on and then Kempower’s website.
By Antti Rantanen

Oh boy!

I have never been as excited about any fast charging system as I am about Kempower’s S-series! But first, a brief introduction:

Fast chargers allow long distances to be covered at a fast pace, but as the number of electric cars grows, the current fast charging network soon won’t be sufficient. People have their hopes up about new fast chargers, but the current way of doing things is unhelpfully old-fashioned — a lonely fast charger at the gas station yard and the next maybe a hundred miles away.

I’ve been driving an electric car for nearly two years now and, during that time, the Finland charging network has grown at a commendable pace, mainly due to expansion of the K-Lataus network (a supermarket chain in Finland). K-Lataus has more than a hundred fast chargers and they’re in pairs, which provides some charging security, but is that enough? If the power unit or some functionality of one charger fails, then the charging point is back to one charger.

Then there are the Tesla Superchargers — they’re completely their own thing, but they serve only Tesla drivers — at least for now. So, what could be the solution?

Image courtesy Kempower.

Kempower has clearly studied charger issues carefully. I recently got a chance to check out its S-series fast charge system, which is different from all the other fast chargers I’ve seen so far — totally and beyond recognition. The difference between this and the familiar ABB and Tritium fast chargers is shocking. Kempower has done things as they should have always been done!

Many electric motorists are familiar with the challenges of fast charging, e.g.:

  • Charging cables too short.
  • Improperly placed / awkwardly placed fast chargers.
  • The charger, electric car, and car app do not tell the charging power – why?!
  • There is only one fast charger and it is in use or broken.
  • Charging is slow — why?
  • The charger is blocked by an internal combustion engine car.

Kempower’s S-series fast charge system manages to overcome these challenges — and it does it completely out of nowhere!

Modular? Yes, please!

It’s … modular!

The S-series charging system consists of a charging cabinet as well as sleek satellites with the best cable management I’ve tested. Image courtesy Kempower.

Kempower’s S-series consists of a charging cabinet (power unit) and satellites. You can connect between one and eight charging connectors to one charging cabinet, and each satellite can have one or two charging connectors. That means you could have four satellite posts with two charging connectors each or eight satellite posts with one charging connector each. Of course, you could put four charging cabinets in a row, for example, so that the charging field can be easily spread and expanded.

The satellite posts are amazingly sleek, as they contain only control electronics and thus do not need as much space as ordinary fast chargers. This allows installation in places that aren’t big enough to accommodate a standard fast charger.

Kempower’s Mikko Veikkolainen presenting the modular structure of the charging cabinet.

The charging cabinet has a control unit, dynamic power management (optional), and slots for four power modules. Each power module has two 25kW power supplies, so a total of 200kW of charging power is available if the charging cabinet is equipped with all four power modules. The system can thus be expanded as necessary, by adding power modules, satellites, and/or charging cabinets. The maximum power of the 200kW charging cabinet can be divided in many ways — e.g., all 200kW for one charging connector or eight charging connectors with 25kW/connector, if all in use. The power of multiple charging cabinets can be distributed to all satellites in the charging field as desired — when the charging power of one car drops, the power modules are released for use by other cars.

Extreme reliability for fast charging operators — and drivers

The modular idea perfectly copes with equipment failures as well. If a power source in a module breaks down, for example, charging continues as normal as the other modules step in. Users charging their cars won’t even notice this as satellites continue to supply power. A minor power drop of 25kW for the whole system probably won’t even be noticed by the users. In other words, the modular design brings extreme reliability to fast charging. This is needed. Thank you!

Type2 and CCS (left), CHAdeMO and CCS (right). In addition to CCS and CHAdeMO fast charging, Kempower’s S-series also supports medium-speed Type2 charging. The satellites can be equipped with different charging connector combinations, such as CCS + CHAdeMO, CCS + Type2, or 2 x CCS.

The challenge of fast chargers is placement and short charging cables

Kempower has definitely researched the weaknesses of existing fast chargers and done things differently, and in the right way. Because fast chargers are often quite hefty and big, placing them is challenging, and charging cables that are too short will not make placing them any easier — especially if the car’s charging port is next to the left front tire, which can make positioning the car on the charger rather tricky if not downright impossible.

Tesla being charged the “wrong way around.”

The cable management of the satellite posts has been carefully thought out and the engineered result is truly functional, flexible, and easy-to-use cable handling! The cables are long enough. They go straight up from the side of the satellite inside the spring structure, so the cables are tangle free and they don’t drag on the ground picking up dirt that scratches the car. Even if the car cannot be parked in a completely optimal way, the car can still be easily charged – something that, for example, Audi e-tron, Jaguar I-Pace, and Porsche Taycan drivers will definitely appreciate!

e-tron is charging while the satellite pole with the CCS connector is on the right side of the car, the car charging port is on the left side, and the car is parked left from the satellite pole. This trick does not work with a standard fast charger.

The charging pole satellite’s user interface operates on a 7″ touchscreen with clear icons, and the amount of text is kept to a minimum. Authentication is done with an RFID tag, but the system also supports payment cards (local payment)! Unlike other fast charging systems, RFID authentication and connecting the charging cable can be done in any order, which makes the charging process super-easy.

The display is constantly on, so you can always see the charging status and charging power (kilowatts). At first glance, I didn’t think the interface seemed all that miraculous, but how wrong I was! The charging curve is displayed with a few clicks, which is an amazingly great feature – this should be standard on every fast charger.

The default screen shows charging status (left). Charging details, time, and QR code (middle). The charging curve is a particularly interesting feature! (right)

And that’s not all! When the charging starts, a QR code appears on the screen — what the heck? A fast scan of the QR code opens a webpage showing the charging session information: battery charge status, charging power, charged kWh, and charging curve (curve is coming soon). Quite an insanely handy feature, especially if you don’t have the car’s own app, or the app doesn’t show charging performance – not to mention the charging curve!

By scanning the QR code, you can get the charging session information to your phone without installing any applications!

There’s a row of LEDs on the side of the satellite post below the charging cable. The blue LEDs clearly indicate the charging status; they light up as the battery becomes full. The green LEDs indicate that the charging point is free, and the red LEDs indicates a fault condition.

If charging power is lower than normal, the system can tell the user why — whether the fault is in the charger or in the car.

Is the battery empty or full? You can see with a glance. LEDs on the side of the satellite post indicate the charging status.

Charging points are easy to find

Because the satellites are quite high, thanks to cable management, they can also be seen from far away in a parking lot. In addition, the tape on the satellites is reflective, so, in the dark, the car’s headlights effectively reveal the location of the charging satellites, not to mention the always-on screen and LED indicators. This, too, has been carefully considered.

The cables reach up to 5 meters (16 feet)!

Costs of a fast charging system

Now, there was no talk of exact euros, and I’m certainly not aware of the prices of fast chargers anyway, but I asked Kempower: How does the S-series differ from its competitors in terms of price? Kempower’s system is more complex than a single 50kW fast charger, after all. But when it comes to several fast chargers, Kempower’s S-series is apparently already more competitive in price! The more power modules and satellites, the cheaper the price becomes per charging point.

Electric cars for staff

Kempower understands that building a charging system isn’t a simple matter; it requires experience with a variety of electric cars, as well as hands-on testing. Kempower as a company has more than a dozen electric cars at its disposal, making testing easier when there are long rows of cars on the yard. This is the right attitude.

I assume — I really hope — that Kempower’s unique and user-friendly modular charging system will do well both in Finland and around the world. The system is so convincing and well-engineered that this is a must-have for charging operators. I’m sure it will hit the market well.

The only thing that annoys me about the Kempower S-series is that it’s not yet in use in Finland! 😉

It was extremely interesting to get to know Kempower’s products. I hope I will be able to come for a test visit for future systems, and most of all, start seeing these user-friendly chargers in Finland.

Special thanks to Kempower and especially Erik Kanerva, Mikko Veikkolainen, and Juhana Enqvist for letting me test the Kempower S-series fast charging system!

Images courtesy of &

Editor’s note: As Americans may have noticed, the Kempower S-series has a great deal in common with ChargePoint stations. ChargePoint is in Europe, but only to a limited degree — entering in recent years. Most systems in Europe do indeed have the many issues Antti noted above, so it is not surprising at all to see him so thrilled about the great design of the Kempower S-series systems. I recall having a similar reaction when I came to the US and used ChargePoint stations (admittedly, not fast chargers, though — we don’t have any ChargePoint fast chargers in my area). —Zach

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