The sleeve with the broken clips at the plus terminal didn't work anymore, maybe I broke the PCB or something, it is very brittle. But I managed to remove the metal to the minus terminal and the red plastic on top of the PCB:
![](http://i.imgur.com/RW3722s.jpg)
I measured the caps in place, so could be wrong, but it says 14 uF, for both pairs, so 7 uF each cap (seems to be parallel). The inductor is 2.2 uH, if the in place measurement is right.
The chip has some label, really hard to read it:
![](http://i.imgur.com/VJqArIg.jpg)
Looks like it says "B041" and date code 1629.
And some more train tests: I did close the lid, this should be heavier than the Batteroo sleeve, and tried it again. But I ran out of Energizer batteries, so I used a Duracell. And looks like the bunny ads are true
![Smiley :)](https://www.eevblog.com/forum/Smileys/default/smiley.gif)
With the Duracell and without the sleeve, it runs for 195 minutes now, instead of 127. But there are different types of the Energizer batteries, maybe this is a type which lasts longer for lower discharge currents.
Then I used a fresh Duracell battery with the Batteroo sleeve, and the train was running for 115 minutes.
Meanwhile the first battery has recovered and I tried it without the Batteroo sleeve. It was running for 7 additional minutes! Of course, this can't be compared because of the longer recovery time and the different battery type, but I guess it will be not much different for the Energizer battery. This means the Batteroo sleeve has no positive effect at all for this train, not even the 3%, because without the sleeve most probably it would have run longer (but maybe a bit slower).
Ok, before I break the second sleeve, too, I'll send it to the next tester, @Ysjoelfir . He might be able to test it with professional EMC and ESD equipment. Was a fun project.