Fail of the Week: Battery Packin’

[NeXT] got himself an IBM ThinkPad TransNote and yeah, we’re pretty jealous. For the uninitiated, the TransNote was IBM’s foray into intelligent note transcription from roughly fifteen years ago. The ThinkPad doesn’t even have to be on to capture your notes because the proprietary pen has 2MB of flash memory. It won an award and everything. Not the pen, the TransNote.

Unfortunately, the battery life is poor in [NeXT]‘s machine. The TransNote was (perhaps) ahead of its time. Since it didn’t last on the market very long, there isn’t a Chinese market for replacement batteries. [NeXT] decided to rebuild the replacement battery pack himself after sending it off with no luck.

The TransNote’s battery pack uses some weird, flat Samsung 103450 cells that are both expensive and rare. [NeXT] eventually found some camera batteries that have a single cell and a charge controller. He had to rearrange the wiring because the tabs were on the same side, but ultimately, they did work. He got the cells together in the right configuration, took steps to prevent shorts, and added the TransNote’s charge controller back into the circuit.

Nothing blew up, and the ThinkPad went through POST just fine. He plugged it in to charge and waited a total of 90 minutes. The charging rate was pretty lousy, though. At 94% charge, the estimated life showed 28 minutes, which is worse than before. What are your thoughts on the outcome and if it were you, what would be the next move?

2013-09-05-Hackaday-Fail-tips-tileFail of the Week is a Hackaday column which runs every Wednesday. Help keep the fun rolling by writing about your past failures and sending us a link to the story – or sending in links to fail write ups you find in your Internet travels.

Tesla Model S Battery Teardown

Tesla Motors club user [wk057], a Tesla model S owner himself, wants to build an awesome solar storage system. He’s purchased a battery pack from a salvaged Tesla Model S, and is tearing it down. Thankfully he’s posting pictures for everyone to follow along at home. The closest thing we’ve seen to this was [Charles] tearing into a Ford Fusion battery. While the Ford battery is NiMH, the Tesla is a completely different animal. Comprised of over 7000 individual lithium-ion cells in 16 modules, the Tesla battery pack packs a punch. It’s rated capacity is 85kWh at 400VDC.

[wk057] found each cell connected by a thin wire to the module buses. These wires act as cell level fuses, contributing to the overall safety of the pack. He also found the water cooling loops were still charged with coolant, under a bit of pressure. [wk057] scanned and uploaded high res images of the Tesla battery management system PCBs (large image link). It is a bit difficult to read the individual part numbers due the conformal coating on the boards.

A second forum link shows images of [wk057] pulling the modules out of the pack. To do this he had to chip away the pack’s spine, which consisted of a 2/0 gauge wire potted in some sort of RTV rubber compound.

We’re sure Tesla doesn’t support hackers using their packs to power houses. Ironically this is exactly the sort of thing Elon Musk is working on over at Solar City.

Extra pleo battery pack

pleo-power-pack-top (Custom)

Those of you who have played with a Pleo know exactly where this is going. The Pleo averages about 30 minues per 2-3 hour charge. Just swap batteries you say? Nope, the battery packs aren’t available. Fortunately, you can make your own pretty easily.  The basic frame is a standard battery pack for 6 AA’s. There are only a few modifications necessary to line up the leads and make it fit once you’ve loaded it with batteries.