T42 battery discharge on sleep mode

[tomer]

Hi..
My T42's battery has 166 cycles on it.
It holds well most of the time except when using sleep mode, where it discharges (slowly) with no particular reason..this doesn't happen when I hiberante .
I notice this happening on all the T42's bought by my employer, although I never took the time to investigate...
anyidea what could be the problem or is this a known issue?

thanks

[christopher_wolf]

Welcome to the Thinkpad Forum

By definition, it will always discharge at a slightly higher rate in RAM suspend than it will in Hibernate. Although it is rather strange to hear it actually has a greater rate of drain. It has to expend energy to maintain the state of the volatile RAM in Suspend, hence the higher drain.

Do you have any quantitative numbers that indicate a drain that is above-average as compared to other Thinkpads or laptops?

[tomer]

Welcome to the Thinkpad Forum

Do you have any quantitative numbers that indicate a drain that is above-average as compared to other Thinkpads or laptops?

I can only compare this to my old broken T22..in which I hardly see any drain in sleep mode.
There is one thing I noticed about the 42 - the CDRW drive led is always on, even on sleep mode. Does this make any sense..?

[GomJabbar]

I have seen the same behavior on my T42 since it was new. AFAIK this is normal behavior. The way I understand it; in Hibernation, your notebook will not use any battery power. You will only get the battery drain that occurs normally with a battery that is not being used. In Standby, your notebook requires battery power to keep the resume information stored in RAM. Without the battery (electrical power), your RAM loses all information stored there.

I too feel that the battery discharges faster than I would expect in Standby mode. I suspect it must have something to do with the motherboard design or the RAM used. I haven't left my computer in Standby (on battery) for more than 6 or 8 hours. I believe I could leave it in Standby (on battery) for maybe a couple of days, but like I said, I really haven't tried to leave it that long. FTR, this information is from viewing Standby behavior in the past. I really haven't checked this recently. I do not use Hibernation on my T42.

[Melvyn]

Mine with 168 cycles go from 95% to 82% in 8 hours at sleep mode.

Anyways, It reach 8 hours at maxbattery and 4 hours at max performance. It's a 9cell battery.

Hope this can help.

[christopher_wolf]

I have left my T43 in standby for almost a week and it has been fine coming through at almost 50%, so that isn't a problem; don't know why it has to be repeated that Suspend drains the battery more than Hibernate, that should be fairly obvious from the get go. The Ultrabay LED is always on in any of these sleep modes and denotes that power is being provided to the bay.

Melvyn, that sounds about right for the drain on the battery.