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Converted Audi A2 goes 605 km (378mi) without charging

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#42
The comments on this one contain an interesting story:

There is much controversy on the 600 km drive done by the initiators, DBM Energy.
But first let's get the facts right. Their spec sheet states a battery capacity of 98.8 kWh and a weight of 350 kg which leads to an energy density of 282 Wh/kg.

According to the inventor, Mr M. Hannemann, the battery capacity left at the end of the run was 10%. These figures are so extraordinary that the [German] automobile association ADAC is sceptical. ADAC had a reporter who accompanied the car in a van with other media people, and says at least twice on the run at night the car disappeared from view for up to 30 minutes.

Mr Hannemann rejects this and says the battery has been proved also on fork-lift trucks. The troublesome point here is that there the capacity of the DBM battery there was given as 240 Ah with a weight of 100 kg, without mentioning the voltage used. Only later, the company testing this battery mentioned a working voltage of 48 V. This would work out to an energy density of only 115 Wh/kg, which is in the current range of Li ion batteries.
Click to expand...
 
#43
dpeilow said:
The comments on this one contain an interesting story:
Click to expand...

Most of those numbers agree with what is found on the company's own website: http://www.lekker-mobil.com/images/stories/pdf/technische-Daten-Audi-A2.pdf (98.8 kWh and 350kg resulting in 282 Wh/kg)

However the numbers in the following quote are a result of confusing different versions of the battery, probably coming from this interview: http://www.cleanthinking.de/kolibiri-akku-praxiseinsatz-papstar-dbm-technologie/8407/

Mr Hannemann rejects this and says the battery has been proved also on fork-lift trucks. The troublesome point here is that there the capacity of the DBM battery there was given as 240 Ah with a weight of 100 kg, without mentioning the voltage used. Only later, the company testing this battery mentioned a working voltage of 48 V. This would work out to an energy density of only 115 Wh/kg, which is in the current range of Li ion batteries.
Click to expand...

The numbers 240 Ah and 100kg refer to an early version of the battery, whereas a later version has nominally 560Ah and 48V. The text doesn't clarify whether the weight of the later version of the battery was still 100kg, and whether the earlier battery had the same voltage of 48V. The company doesn't fully charge the later version of battery, only 3 hours of 130 Ah (= 390 Ah), apparently due to the specific charger being used.

So if the weight remained the same, and if the nominal value was correct, this would be about 270 Wh/kg, quite close to the 282 Wh/kg above. However, the nominal value apparently hasn't been confirmed in the fork-lift company's usage (or at least not by this interview). It is only using a charging level of 390 Ah which implies at least 187 Wh/kg (if the voltage it gets is 48V). 187 is 2/3 of 282, and the last third needs a more solid "proof". Also, since the article (at www.cleanthinking.de) presents an incomplete set of numbers without even trying to address the resulting lack of clarity, I'd hesitate to rely those number that are given. On the other hand, most who cast doubt on the 605 km drive, seem to have been using wrong numbers for their calculations.
 
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#50
They have a lot of different people and groups involved in the fraud with them if it is. It will also be quickly exposed if they can't deliver an actual product that performs as specified, so I'm not sure how they'd expect to make any money or get away with it.
 
#51
Interesting that the battery caught on fire. Lithium metal is one of the most volatile type of batteries and it seems for their forklift batteries, they also have a history of fire.

I also feel there is a good chance this is a fraud. I was already very skeptical when it was announced, esp since there were no pictures of what the pack looked like (which is unlike all EV makers I have seen; they like to show off their pack a lot). And as a battery OEM, I don't see why they don't have some sample cells available for third party verification. If they were serious about getting them to mass market, and their cells really are as good as they claim, third party verification will give them enough credibility to get significant investors.
 
#56
Anyone want to take a crack at a better translation that google?
http://www.dbm-energy.com/de/presse.html

Looks as if they did a new test and got 454.82 kilometers from a 62.928 kWh pack, which may or may not be impressive depending on the speed.

OK, there is a PDF in English http://www.dbm-energy.com/de/dlfiles/3.pdf
Still not clear what actually happened.
All test results of the KOLIBRI technology were subsequently verified and
validated by DEKRA. This includes the initial battery charge after handing
over the vehicle, recharging the battery over charging period of 12 hours,
discharging the battery over a distance of 100 km at a constant speed of 70
km/h as well as determining the vehicle’s driving resistance.
The peak speed measurement during the 30-minute maximum speed
segment was 100 km/h. The required condition of covering a distance of
300 km within 7 days was met in one session on a roller dynamometer,
indicating a range of 454.83 kilometers with the 62,928 kWh LMP battery.
Adjusted for the battery capacity of 98 kWh at the time of the worldwide
range record, the range would have been 714 km. The efficiency of the
LMP battery was determined to be at 97%.
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#57
The test was done at the testing facility of Dekra. They put the car up on the roller dynamometer for a test called ECE-R101 http://www.unece.org/trans/main/wp29/wp29regs/r101r2e.pdf. This a European standardized test for measuring co2 emissions and fuel consumption. The test is known to be unrealistic. I don't believe a single car has come close to the test results in real life use.
The test covers a simulated course of 11km or 6.8 mi. It simulates an urban and extra urban cycle. The average speed in the whole test is (please fasten your seat belts) 33.6 km/h or 20.9 mph. Top speed in the extra urban cycle is 120km/h or 74.5 mph for 14 seconds. (pages 51-54 of the test protocol above)
 
#58
all of this measurement does not matter. what is important: what is the real usable capacity at what weight? means the usable energy density and the charging-/decharging efficiency as well as the charging time and the power density.
and for the cost efficiency: what is the cycle life: #full cycles until 80% of starting capacity.
 
#59
JRP3 said:
Still not clear what actually happened.
Click to expand...

So far, the texts don't seem to mention the weight of the battery, only the total vehicle weight being less than 1500 kg. So we can't say much about the battery itself, except that it was tested for safety in various ways, where it apparently did well (does not accelerate fire, for example).

454.82 kilometers is about 283 miles, and achieving this with a pack of about 63 kWh equates to about 223 Wh/mile, but says more about the EV conversion than about the battery. (The pack in the 2010 record-claiming drive was said to have 98.8 kWh, and a similar EV conversion was said to have achieved about 372 miles with this larger pack, which equates to about 266 Wh/mile).

The point of the test was to demonstrate that the battery is capable of enabling an EV to travel a certain range meeting some official specification. The test showed that the combination of battery and EV conversion exceeded the specified minimal range by a good amount.

I think most of us where looking for an independent verification for the energy density of the battery, which this test doesn't seem to give us.
 
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