battery Logo Designs - OOMPH

After re thinking a lot about what I could name this battery brand I came with with the name OOMPH. I wanted it to stand out and be very different to other battery brands, add a little bit of quirkiness to it. The concept behind the name is adding that more oomph to your power, and it has that little more oomph to other battery brands. The slogan is ' Add that little more OOMPH to your daily life.'

My initial logo ideas are below...

I then transfered this logo on to a battery to see what it looked like....

I feel after evaluating what the logo looks like on the battery, it was not working, so i decidedto develop the logo further. 

The idea for the logos below was to use the power symbol as an o and also trying it without using the power symbol. 

I then tried using these logos on the battery to see what they looked liked...

Even though I felt some of these were working a lot better than my initial logo designs, I developed further. 

My final logo design