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Step 5Safety first: test the darn thing
I've seen some people who've posted how-to's for replacing laptop cells immediately replace the cells seal the battery and use it. This is extremely dangerous, unless you want to cook your lap. The quality of the cells purchased is unknown, and needs to be tested. (manufacturers of laptop batteries quality test their batteries before shipping them off. And sadly, sometimes a batch can go undetected)
-So, attach alligator clip w/ wires to the new pack and bury it in the sand (don't forget which clip belongs to which wire)
-Here's the tricky part (yet another thing other how-to's messed up.) The reason why I said not to disconnect the original (dead) cells from the smart circuit (which I inadvertently did. Don't worry, it was my test battery) is because the circuit requires a constant power supply or the smart circuit guage messes up. You might wonder why worry about the gauge if it doesn't contribute to charge and discharge cutoff. This is because the laptop requires a signal from the circuit before the laptop will turn on (in case the cells are thought to be drained and draining more, even for a second can kill the li-ion cells. Or simply, something's wrong with the battery). So, connect the new pack to the circuit before disconnecting the original battery cells.
-However, what if you're using alligator clips, which is a temporary connection? How can you disconnect and solder on permanent connections? Either, solder on the new connections while leaving the clips connected, or you can even use a power brick with about the same voltage as the whole battery pack (a 11.1 v pack actually ranges from 12.68 v to 7 v so a power brick at 12 v is ok). But remember to add a resistor between either the anode or cathode of the power brick and the circuit, so you won't kill the circuit board. (Not connecting intermediate pins should be ok, I haven't tried. If you worry about this, you can reuse your dead cell as a temporary power source while soldering on the new pack.)
-Plug in the battery circuit into the laptop and place it FAR AWAY from the battery pack. Test the battery pack. Charge is first, then completely discharge it, then charge it again. This is when you should watch over the battery pack intently, because it might explode (sand should stifle the fire, but immediately unplug the battery from the laptop.) The fear here is the type of secondary circuit used to monitor end states. End Voltage type circuit is ok, but end amperage is no good. If you can tell what type you have just by looking at the circuitry, then you're in good shape, but if you can't there's always the fear of an explosion. From my experience, the circuit is typically end voltage.
-So, attach alligator clip w/ wires to the new pack and bury it in the sand (don't forget which clip belongs to which wire)
-Here's the tricky part (yet another thing other how-to's messed up.) The reason why I said not to disconnect the original (dead) cells from the smart circuit (which I inadvertently did. Don't worry, it was my test battery) is because the circuit requires a constant power supply or the smart circuit guage messes up. You might wonder why worry about the gauge if it doesn't contribute to charge and discharge cutoff. This is because the laptop requires a signal from the circuit before the laptop will turn on (in case the cells are thought to be drained and draining more, even for a second can kill the li-ion cells. Or simply, something's wrong with the battery). So, connect the new pack to the circuit before disconnecting the original battery cells.
-However, what if you're using alligator clips, which is a temporary connection? How can you disconnect and solder on permanent connections? Either, solder on the new connections while leaving the clips connected, or you can even use a power brick with about the same voltage as the whole battery pack (a 11.1 v pack actually ranges from 12.68 v to 7 v so a power brick at 12 v is ok). But remember to add a resistor between either the anode or cathode of the power brick and the circuit, so you won't kill the circuit board. (Not connecting intermediate pins should be ok, I haven't tried. If you worry about this, you can reuse your dead cell as a temporary power source while soldering on the new pack.)
-Plug in the battery circuit into the laptop and place it FAR AWAY from the battery pack. Test the battery pack. Charge is first, then completely discharge it, then charge it again. This is when you should watch over the battery pack intently, because it might explode (sand should stifle the fire, but immediately unplug the battery from the laptop.) The fear here is the type of secondary circuit used to monitor end states. End Voltage type circuit is ok, but end amperage is no good. If you can tell what type you have just by looking at the circuitry, then you're in good shape, but if you can't there's always the fear of an explosion. From my experience, the circuit is typically end voltage.
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the circuitry with the battery controls the charge speed because the cells heatup if charged to fast, and you are anticipating a blow up!
id recommend having a series resistor between each connection to the old battery (excluding GND) to limit current.
So I went about doing this before I found your instructable. I was replacing my dead cells from a tutorial I found online. They did not however warn about the smart circuit needing power. It was disconnected for over 2 weeks. When I put the new battery pack in windows detects the battery at 0% and if i remove the AC power it turns off immediately (like you said the gauge is wrong). Is there anyway to fix this?!?!
Thanks!
What are my options?
To change the 'Battery->Critical battery action->'On battery' setting to "Do nothing" using powercfg.exe