Dell E6400 PT434 type Battery Charging Stuck at 1%. Battery Pinouts?

[Bowline]

My question pertains to understanding the control circuity inside a Dell PT434 type battery used in Dell E6400, E6410 and other Dell notebooks?

Does anyone have a circuit diagram for the inside of a Dell PT434 battery and/or a description of how the control lines work to control this battery?

My reason for asking is I have a battery which I cannot get to charge beyond 1% in a Dell E6410 or E6400.
The LED bar graph charge indicator on the battery shows one LED lighted when the info button is pressed.
I have tried multiple different Dell power adapters. My Dell E6410 and E6400 notebooks charge other Dell PT434 batteries properly.

This battery shows as being healthy in the F2 setup battery screen and the battery otherwise seems good.
This battery had this same problem once about 9 months ago -- and then magically started working again -- until the problem occurred again recently.

If I can learn what the battery pin outs are and understand the control lines to the battery, I am hoping I could partially charge this PT434 type battery using a lab supply. My hope is that once I get the battery partially charged, it might work properly again in the actual Dell E6410 or E6400.

I have searched multiple forums and have found posts from others who have experienced this problem with batteries that get stuck in a state where the battery shows charging -- but never goes beyond 1%. The battery shows as being healthy.

A post I found in another forum said he had found success with a battery which was stuck at 1% charge by inserting the problem battery in a different Dell E6400 which was already booted up into Windows 7 with no battery installed -- and
then inserted the problem battery. The poster said he found the battery would start charging -- he would charge it up to 50% and then -- the battery would charge properly in the original E6400. I have tried this method without success.

I found a schematic for the Dell E6400 on an earlier badcaps post:

https://www.badcaps.net/forum/troubl...-diagram/page2

Page 43 of the schematic shows the Primary Battery Connector in the upper left hand corner of the page.
The schematic page 43 is showing 11 pins for the battery connector -- however -- my Dell E6400 has 9 pins and the PT434 battery has 9 pins, so I am uncertain if this is the correct battery pin out.

I tried probing the contacts of a working good PT434 battery using a voltmeter. So far, I have not been successful finding 11.1 volts out on any pin combination.

Does anyone know if I need to pull-up or down some combination of the other pins to this battery to enable the power output of this battery?

[mon2]

From my limited understanding, there is a BMS controller board (battery management system) on each battery pack. Then there are the raw battery cells. If the battery cells deplete to a very low value, the BMS will lock out battery pack for safety.

Be sure you are using a suitable power adapter to charge this Dell. The adapter must be a Dell product due to the 1-wire communication that is used to identify the power rating. Confirm this by reviewing the BIOS screen which will offer the details of your power adapter. If the power adapter is missing the 1-wire center pin, the battery will not charge.

[Sephir0th]

It is exactly like that. Sometimes you may be lucky and it's just the fuse blown up but usually you end up with re-balancing the cells and also clearing the faults recognised by the Controller to unlock the battery again.

Of course only economical when you are regularly working on batteries, since the equipment which can deal with that is expensive, e.g. NLBA

Personally i don't do anything of what is described above since in my opinion it is a bad idea to play with batteries which are locked. So it's your own responsibility to understand the danger. For you and for your customers.

[Bowline]

I have several genuine Dell power adapters suitable for E6400 or E6410 notebooks that I use. All of these power adapters worked OK with this battery before it got stuck at 1% charging.

This battery is a 9 cell knockoff of a Dell PT434 type removable battery - not a genuine Dell battery.

I would like to provide some more information about my experience with this battery to explain why I think this battery may not be "permanently" locked.

I bought the battery a year ago. When I first received the battery, I charged it to 100% with the notebook powered on and then disconnected the power adapter until the battery drained completely and the notebook shut off. I did this process 3 times and the battery charged up properly each time after being completely discharged.

After the initial testing, I did not deliberately drain the battery when I used the notebook. I would typically power the notebook up about once a week with the power adapter connected. The Dell power adapter was plugged into a power strip with an On/Off switch. Occasionally I unknowingly powered up the notebook when the power strip switch was in the Off position. If I did not notice the power strip switch was in the Off position -- I might drain the battery unintentionally while using the notebook. But the battery always would charge properly back to 100%.

When I was done using the notebook, I would shut it down, close the notebook lid, and disconnect the power adapter.

Once in a while -- the notebook apparently did not shut down completely -- because I found the battery was completely drained when I powered it up again a week later. This did not happen very often.

3 months after I had purchased the battery -- after I had shut down the notebook for a week -- I found the battery completely discharged. When I plugged in the Dell power adapter, it showed the battery good, charging -- but charging stayed stuck at 1%. When I pressed battery "info" button -- one LED lit up on the battery charge indicator.

Nothing I tried would get the battery to charge past 1%. I gave up experimenting -- but left the battery in the notebook. (This was 9 months ago.)

I continued to use the notebook about one day a week, disconnecting the power adapter after each use. I occasionally checked the charging status of the battery -- but week after week it stayed stuck at 1%.

After more than a month had passed -- one day I noticed the the battery was 100% charged again! (9 months ago.)

What happened? I have no idea. Clearly -- the battery WAS NOT permanently locked out 9 months ago.

After this incident 9 months ago the battery worked normally. It would power the notebook with the power adapter disconnected. I tried to to be more careful to make sure the notebook was completely shut down before disconnecting the power adapter when I was done using the notebook. All was good for 9 months.

Then two weeks ago -- when I connected the power adapter and powered up the notebook after the power adapter had been disconnected for a week -- I found the battery completely discharged and stuck at 1% charging -- just like what happened 9 months ago.

Because battery "healed itself" 9 months ago -- it may do the same thing after some weeks or months go by. But this experience has made me want to understand the control signals between the notebook and the battery BMS circuitry.

I have found posts in other forums for the E6400 class of Dell notebooks and batteries that indicate this is a problem many of this series notebook has -- where the battery does not seem to be in a "permanent lockout."

[Bowline]

Here is a 2016 post I found on a Dell support forum:

I have owned 5 Dell Laptops over the past 12 years. Since Windows 7 There is something wrong with the code in dell's configuration or bios. NO ONE will address the issue. I have seen this happen in MANY support sites, and in person. "0% Battery plugged in, not charging". If you let your battery die while you are logged into windows 7 or 10, You have about 75% chance of getting this message. Sorry there is no update that I know of, there is no setting that has worked and I have tried 8 different recommendations. Nothing worked. So I bought new batteries and new chargers several times and it was pissing me off. So it happened to a 10 day old battery. I had this idea to put it in my other dell laptop while it was plugged in and LOGGED IN to Windows. I had tried everything but that! It started charging my battery! I let it charge to 50% then put in the original Dell, booted up and it showed 50% avail, charging. I couldn't believe it! I then charged up FOUR "dead" batteries for these two laptops. Using that method. So now I have six batteries and I rotate them I NEVER LET MY DELL DIE! Sorry, but your only solution is to flush money or find a friend who has a compatible model that will let you charge it up. Or buy another Dell. But support has never acknowledged this issue.