Is it possible to measure the battery voltage on a framework 13 with a voltmeter?
should battery voltage show across the + - pins when it’s disconnected. or does some kinda communication over the other lines have to “turn it on”
Anyone willing to measure a known good one for me?
My battery’s shows 0 volts, and i’m having a won’t boot problem, which feels like it might be “no battery” problem.
after some internet research. I’m suspecting, that that at least sys_pres “system present” has to be activated. (possibly tied to ground) before the internal circuitry will allow battery voltage out.
so.. my real question, is there a good way to test the battery is ok on it’s own?
The CLK_SMB and DAT_SMB is a SMBus / I2C bus that you can read.
If you have a constant current supply, you could try charging it with a very low current. Maybe 150mA. It might just wake it up enough to say hello to you over the SMBus.
But the easiest way to test if a battery is bad, is by replacing the battery with a known good one, and see if it fixes the problem.
Thanks for the reply.
Hmm, I’m not setup to talk to an SMBus.
I wish i had one handy. or at least could confirm it is the likely culprit of my booting problem.
I got the same 0 volt when I disconnected the battery in BIOS. if I remove the battery without disconnecting it in BIOS I can get both SMB reading and voltage measurement.
If the battery won’t connect even if you plugged in and connected to AC(should be at least 60W), either the BIOS has communication error and need reset (do this without a battery if you can’t boot into BIOS with battery), or the battery has fried/shorted and this prevents the DC BUS from energizing, or the BMS gave up the ghost and prevents the EC from initializing, in this case replace the battery or(as an advanced user) charge the battery cells using a bench power supply and reprogram or replace the BMS chip
Thanks for doing that.
it at least shows the battery itself can be in either state, show or don’t show voltage on the output.
not sure how to open up the battery to get at the cells in a reversible manor.
I’ve never gotten into the bios. so I didn’t do battery disconnect the laptop just sat for a while.
so, i guess without opening the battery up, or learning how to communicate with it via SMBus i can’t conclude wether it’s bad or not. nor can I be sure wether a bad battery would be the reason for my boot up problems but I’ll continue trying to debug in that thread and with support and see if it leads back to the battery or not.
There is an EC CCD that accesses the console port of the EC. You could use it to query the battery before it turns on the laptop.
I’m not sure how that all works. (sounds cool tho. )
is that using ectool? I can’t boot so I can’t use software on the computer to test the battery.
Well, you could probably get a EC CCD if you wished.
The Embedded Controller (EC) is a very small ARM chip that controls all sorts of things, one being the boot up procedure. The EC runs even if you have powered off the laptop, but have the PSU still plugged in.
So, if you cannot boot the mainboard, you will still be able to talk to the EC and collect useful information. For example, the EC has a “battery” command that reads the values stored in the BMS via SMBus. You can get this information even with the laptop powered off.
Closing this out.
the battery was dead. one cell of four drained.
because my battery was dead the bms wasn’t allowing any discharge. so not being able to measure voltage on the connector, and not having put the battery in disconnect mode was a pretty good clue the battery was dead.
using a CCD to talk with the EC, would have shown no battery connected flag. but i didn’t figure out how to try that.
examples from ectool battery run from linux
Flags 0x0b AC_PRESENT BATT_PRESENT CHARGING
vs
Flags 0x09 AC_PRESENT CHARGING
You can recycle the dead 0.4V and repurpose the three 3.7V to a power bank
true. my wife laughed at me, when I suggested it. (i have a lot of batteries lying around.. )