R40 Battery Charging Problem

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freesteamin · #1 Post by **freesteamin** » Wed Jan 31, 2007 7:30 pm

Over the past two months I've been having a battery charging problem similar to that mentioned in several other threads. I haven't figured out the complete symptoms yet. At times the battery will charge to 100% then stop charging, as it should. At some point soon after, even with the AC plugged in, the battery will start discharging slowly until it drops to 0%. The computer will continue to operate on AC, of course. I can sometimes get the battery to start charging by restarting the computer and sometimes by removing the battery for a minute or so then reinserting it with the AC plugged in. At that point the battery will again charge normally to 100%. I have installed all the latest drivers from Lenovo and the latest software from Microsoft. After reading the forums, I tried pressing the power button ten times then press it for 30 seconds but it had no effect.

Terrahawk · #2 Post by **Terrahawk** » Wed Jan 31, 2007 9:14 pm

As far as I am aware, the proper behaviour is:

- charge up to 100%
- stop charging
- battery slowly self-discharges if computer is on AC power
- at 95%, start charging again up to 100%
- repeat

I have gathered this information from the observation of 3 R40s and an X20. Your problem would seem to be that something in your computer believes it is running on battery while the AC is plugged in.

Interesting thing is though is that the battery is the device that ought to control the charging system. Maybe your battery has issues - are you able to try using another one from somewhere?

freesteamin · #3 Post by **freesteamin** » Thu Feb 01, 2007 6:37 am

Thanks for the reply. I don't have access to another battery. My initial reaction was to buy another battery but I hate to spend that much money on what might be a wild goose chase. In all other respects the battery seems normal. It takes a reasonable time to charge (1:30 or so) and, when on battery power alone, discharges in a reasonable amount of time (2:30-3:00) .

freesteamin · #4 Post by **freesteamin** » Thu Mar 08, 2007 10:13 pm

I purchased another battery (new) but I get the same symptoms. Computer recognizes that it is on AC but the battery slowly discharges to 0%. Sometimes I can get the battery to start recharging by removing and reinserting the battery or by shutting off the machine and restarting but not always. If it does start recharging it continues to 100% then slowly discharges. During the discharge time, the battery info screen does not show the battery as charging or discharging i.e. the current and voltage monitors are blank.

mitchellst · #5 Post by **mitchellst** » Thu Mar 08, 2007 10:15 pm

Sounds like your motherboard.

hoplite · #6 Post by **hoplite** » Fri Mar 16, 2007 1:51 am

You probably already tried this but...

I was having similar problems with two of my R40s. They wouldn't charge and sometimes when they were on the AC adapter they'd slowly discharge. If I unplugged the battery cord and jacked it back in the battery monitor would show they were recharging for a split second then there would be no activity.

I thought I had two batteries that had deep discharged since they were in storage for about a year. I resigned myself to having to shelve out the money to buy two batteries when by chance I happened to use my brother's AC adapter when I was visiting him and lo and behold both batteries charged fine.

Before you check the mobo or the batteries I'd try a different AC adapter. Who knows maybe you'll get lucky like I did.