Epsilon 12V150Ah wins promobil test

In issue 9/2026, the German trade magazine promobil tested nine current lithium batteries in DIN housings in the lab. The Super B Epsilon 12V150Ah won the test with 91 out of 100 points.

The rating says even more than the score: the Epsilon is the only battery in the test rated "sehr gut" (very good). All other models were rated "gut" (good) or "befriedigend" (satisfactory). The runner-up finished 15 points behind.

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What promobil measured

All measurements took place in a separate test room and were carried out by promobil staff only. Every battery went through the same programme:

• Capacity: After a full charge and one hour of balancing, each battery was discharged in a controlled way at 0.5 C. A measuring shunt in the ground cable recorded every second how much capacity was actually available.
• Load: For ten minutes, each battery had to deliver the maximum continuous discharge current approved by its manufacturer. How far the voltage drops says a lot about the quality of the internal cell connections. promobil then used up to 480 A to test when the BMS shuts down.
• Frost: The batteries were discharged to 80 percent and kept in a freezer at minus 12 degrees for at least twelve hours, until the core was below minus 5 degrees. Charging was then tested. Charging below zero is critical for lithium cells, which is why the BMS controls an integrated heater.
• App: Connection, range of functions, ease of use and security.

Scores were given in four chapters: load capacity (40 percent), app (20 percent), housing and features (20 percent) and price (20 percent). A "sehr gut" rating requires at least 80 out of 100 points.

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Load capacity: 36 out of 40 points

In the most important chapter, the Epsilon achieved the best score in the test. The difference lies in the voltage under load.

The Epsilon is approved for 200 A continuous current, which equals 1.33 C. After five minutes at this current, the voltage was still 12.81 volts. No other battery held a higher voltage under its rated continuous current. That earned the highest rating in the test for voltage drop under load.

In the capacity measurement, the Epsilon reached 149.9 Ah, or 99.9 percent of its rated capacity. It passed the ten-minute load test without issues, and in the shutdown test the BMS intervened at 350 A after 15 seconds.

The frost test also went without issues. That is not a given: with several batteries in the test, the BMS started oscillating after freezing or even shut down completely.

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App: 20 out of 20 points

promobil points out a common problem in its test. Many battery apps are very similar, and access protection is often missing. That means batteries can be read out or even reconfigured with third-party apps. Only three of the nine apps in the test were protected.

The Epsilon is one of them. Its app is secured with an individual password, printed on a sticker under the service flap. Values are clearly labelled, the structure is well thought out and the settings are extensive. The result was full marks, as the only app in the test.

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Housing and features: 20 out of 20 points

Here too, the Epsilon is the only battery with full marks. That comes down to details you notice in daily use.

When closed, the folding carry handles cover the double screw terminals, which have an integrated temperature sensor. Additional screw terminals for measuring and peripheral devices were unique to the Epsilon in this test. More clearly labelled connections sit under a central flap. Three status LEDs use a traffic light system to show whether everything is fine or a warning is active.

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Price: 15 out of 20 points

In the fourth chapter, promobil rated value for money and warranty. Here the Epsilon scored 15 out of 20 points. It does not change the overall picture: with 91 points, it finished well ahead of every other battery in the test.

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The result

The Epsilon 12V150Ah is the only battery promobil rated "sehr gut". It held the highest voltage under heavy continuous load in the test, has the only app with full marks and a housing that also earned full marks.

Want to see the Epsilon for yourself? Our dealers are happy to help.

Source: promobil 9/2026, test of 9 lithium batteries in DIN housings. Tested model: Super B Epsilon 12V150Ah, 91 out of 100 points, rating "sehr gut", test winner.

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