Samsung Galaxy Tab, Module Progress, Problems With A New Batch Of A123 Cells

I finally got around to test fitting the 7″ tablet in the center console of the Porsche and this is one of those times where luck turns out better than good planning.  The tablet fits perfectly and requires no cutting and no special trim panel to make it look nice.  The one issue that I knew I would have right from the start is lack of space to run the audio output jack as well as dock connector out the left and right sides of the tablet.  The solution is to remove the back cover and relocate the jacks for easy use.  I also need access to the power switch and possibly the volume controls that are normally on the “top” in the orientation that I will be mounting the tablet, this means soldering extension wires to some very tiny buttons inside the tablet and routing them to an external switch.  I may be able to use the ignition switch as a trigger to turn the tablet on and off when the car is turned on and off.  Otherwise I will use one of the vacant switch openings to install a momentary switch that will be re purposed as the on/off switch to the tablet, this may also be handy to turn on the tablet while the car is off for testing, internet or watching movies.  The tablet comes with a good size lithium battery that I will use to power the tablet while driving, it will charge along with the main pack when the car is plugged in.

Above:  Tablet test fitted in the center console to evaluate “glare”, looks good right now but might be an issue with the sunroof off.

Above:  Back cover removed, battery and guts visible.

Above:  Close up dock connector removed and rotated 180 to face inwards.

Above:  Close up of the new switch wires, 30awg soldered directly to the surface mount switch terminals, VERY TINY!

I still have some work to do to the tablet before it gets mounted to the center console for good.  I need to secure the wiring and new positions of the dock connector, and switch wires along with add RCA jacks to the tablet for easy integration into the car stereo.

 

The module assembly is coming along nicely, now that all of the details are worked out everything is going together nicely.  I have 5 finished modules, two of which I’m using to power the chargers for further cell testing.  Once the battery box is finished and I can start installing things permanently I need 8+ modules to start driving the car again.  12 modules should give me decent performance and all 24 modules will give me excellent performance and the full designed range.

 

In the early days (a year ago) when I bought my cells there wasn’t much available, I jumped on some tabless cells that work perfectly but had been de-tabbed by the factory.  These cells are simply a pain to work with, they require uncovering the tab under the plastic/aluminium casing to make the connections.  This works well, but is simply time consuming and messy work and doubles or triples the cost of the cells with the added labour.  I just bought a new batch of cells to finish the car and they have short but more normal tabs.  There is still an issue with what I ordered and what I received, those in China aren’t the best vendors, I made it very clear the type of cell tabs that I wanted and we agree’d on pricing etc.  They came back with a higher cost due to a “mistake” in the quote, I think this is poor business practice as I had already sent the payment but before shipping they demanded more money.  So buyer beware when buying directly from China.  The cells are still a good deal with potentially useable tabs, not the tabs that I wanted though so we will have to see if they give me some of my money back or not due to their quite significant error.  I will have to test a module made from these cells and see if they can handle the current, most likely they will only be good for electric bike packs.  They also aren’t made in the country that I was told, my existing cells were made in Korea so I was happy when I was told the “short tab” cells were also made in Korea, but I received cells marked “made in USA”.  These cells don’t have the same discharge curve to the Korean cells, they are still good, but different, so if I am able to use them half of my pack will behave slightly different than the other half.  If they don’t back their product I may have to warn against doing business with this company and stop recommending these cells on this blog and all forums that I visit (diyelectriccar.com, endlesssphere.com etc).  To date I’ve been one of the biggest supporters of these cells, but if you can’t buy them from a fair company that isn’t out there to rip you off and send you what you order it’s just not worth it.  I won’t mention the company yet, I’ll give them a reasonable amount of time to respond and fix the error.  I only have 70 of 152 cells because of DHL’s wonderful shipping but that’s another story and I’m sure the rest will arrive soon.  It’s still pretty early to tell as I’ve only tested 36 cells, but the average capacity is down slightly and the IR is up slightly on these made in the USA cells vs the Korean cells that I’ve been using.

 

You also may have noticed I’ve gone back to my Nikon SLR for photo’s, the in car shot is with my Iphone 3GS, but the remainder are obviously much better quality from the Nikon.  I had gotten lazy and simply used the Iphone or tablet camera because they were handy, I will try to use the Nikon again as the images are drastically better quality.

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