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Thread ID: 77357	2007-03-07 01:09:00	Using Laptop without battery	R2x1 (4628)	Press F1

Post ID	Timestamp	Content	User
530778	2007-03-09 19:09:00	If you are running the laptop off mains most of the time, you really should have the battery out. I have seen many a laptop battery ruined from being attached to the mains for weeks on end, such as my mothers old laptop on which you would be lucky to get 20 mins of use out of the battery.	lagbort (5041)
530779	2007-03-10 00:27:00	Repacking a Lithium-Ion battery is not a DIY operation. An important part of the pack is the microcontroller which supervises the charging so it doesn't become a bomb. Some have to be set up by an external computer to match new cells. Some even have to be kept running (with an external supply) while there are no cells connected, or they shut down permanently.	Graham L (2)
530780	2007-03-10 01:52:00	Repacking a Lithium-Ion battery is not a DIY operation . An important part of the pack is the microcontroller which supervises the charging so it doesn't become a bomb . Some have to be set up by an external computer to match new cells . Some even have to be kept running (with an external supply) while there are no cells connected, or they shut down permanently . You are absolutely correct, Lithium technology has the potential to make expensive smoke with dangerous temperatures and occasional explosions . (But, isn't that why we have fire insurance? :groan: ) In this case I am fairly familiar with Li-Po technology, I have a few of them that are usually discharged at 15 to 20 times their rated capacity . For those cells, and the proposed laptop pack, I have a cunning German microprocessor controlled charger that does the necessary monitoring and controlling . Since I don't have access to the requisite test equipment or the large selection of cells to make up balanced packs, I use a cell balancing setup that equalizes the individual cells before, during and after each charge cycle . Being a bit of a coward, my battery packs are still in a fireproof box for charging and at least the next 20 minutes . Don't get me wrong, I like Lithium cells, but I have a great deal of respect for them . Interestingly, many manufacturers recommend that Lithium batteries are stored at 0 to 10 deg C in a 40 to 50% charge state for best life . Neither of these conditions is satisfied in an average laptop, so the suggestion to remove the battery during mains use is good advice from the battery's viewpoint . I wonder just how much mains transient suppression the charger has without a low impedance battery "floating" across its output? Cheers .	R2x1 (4628)
530781	2007-03-10 04:13:00	"Venting with flame" is the official, comforting, description of the failure mode. :D If you are using Li-Ion cells in model applications you obviously have taken warning from the early problems experienced by people who "knew all about" baattery technology because they had used NiCds. They found that Li-Ion was different, expensively :cool: The charger power supply is usually switchmode, with very good regulation. Then there's another switchmode supply which produces the multiple voltages for the computer. That gives two stages of surge suppression, with or without a battery. You might still have problems: the laptop might decide that there is "no" capacity in the battery (because it can't talk to the proper battery controller) and shut down. ;)	Graham L (2)
530782	2007-03-10 06:58:00	Ah thanks for that Graham L. Seems it will be safe enough to run with no battery then. Maybe it's time for me to accept that the manufacturer has probably taken a fair few steps to protect his market in replacement batteries. It rankles to pay the sort of figure usurious figure they demand though. That venting with flame scenario is offputting, the web pictures and sounds are bad enough, being able to smell it and feel the warmth is not what I crave just yet.	R2x1 (4628)
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