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Battery percentage suddenly drops from ~60% to 7%

Battery percentage suddenly drops from ~60% to 7%

Asked by: Guest | Views: 151
Total answers/comments: 5
bert [Entry]

"Same problem here (drop from 70% to 7%) after following these instructions: https://help.ifixit.com/article/265-batt...

I also did the SMC reset.

I am getting about 3hrs of battery life with just the activity monitor and with the screen on (66% of brightness)

I did have a similar problem two years ago with another ifixit battery I bought for a MBP 2011 13”, I sent it back and bought a Newer Tech battery that also reports an inaccurate percentage. I am really frustrated with this after spending 80€ on a battery that is supposed to be of high quality."
bert [Entry]

"I’m having a similar issue, but I don’t think it’s the battery. At least not the battery cells. I recently replaced my battery using an IFIXIT battery. I starting seeing the problem you’re describing, rapid drop in displayed battery charge, with my old battery. The Apple diagnostics indicated my old battery was ready for replacement, so I assumed the battery charge was actually dropping that quickly due to a failing battery. However, I’ve seen that happen with my new battery as well.

Here’s an example of how my new battery is performing. I was running off battery only and the displayed charge went from 100% to 72% in what appeared to be a normal rate of discharge. I had been using my MacBook Pro in a typical way; emails, web searches, image viewing, etc. To go from a displayed charge of 100% to 72%, it took ~ 1 hr 50 mins. At that time, the display jumped to 7%. My plan was to continue using the laptop until the battery fully discharged. I continued working for another ~ 40 mins and the displayed charge stayed at 7%.

I had to move on to something else, but left the laptop on. The display sleep was set to 7 mins and the computer sleep to 15 mins. I would wake it up every 15 to 30 mins, navigate a bit and then let it sit. The displayed charged stayed at 7%. I actively used the laptop for ~ 2 hrs 30 mins and then the sleep/wake up cycling for another ~ 1 hr to 1 hr 30 mins. The battery completely discharged sometime between the 1 hr and 1 hr 30 mins mark. I didn’t witness it.

So, I think that’s fairly normal battery performance, ~ 3 hrs 30 mins to 4 hrs running off battery only power. Therefore, I think the battery cells are performing fine. That leaves the battery charge sensing circuitry. I’m not sure if that function is performed on the logic board or the small circuit board on the battery assembly. I’m planning on getting a new logic board for another problem, so I’ll see if it also fixes the battery charge state display. I think the graphics card that’s built onto the logic board is having issues, as I’ve been having a problem with the screen randomly blacking out, while the computer stays running.

I tried to get a logic board from IFIXIT and a couple of other sources, but they were all out of stock. When I get a new one, I’ll post the results. If the battery charge sensing function resides on the battery assembly circuit board, then a logic board swap won’t solve the problem.

If anyone out there knows where the charge sensing function is performed, that information would be helpful."
bert [Entry]

the censers that control the % of battery may be shot or they may not be wired up correctly
bert [Entry]

"So, it sucks to say this on the iFixit forum but… I got a battery off Amazon and it seems to be working fine. Got 3 hrs of editing on it and it went just fine. No sudden drops etc. Havent tested internet browsing etc but all seems regular. Will report back in a bit with more testing. All in all I can say that it was not a motherboard issue, it wasn’t related to any repair mishaps or else. Simply a bad battery (well.. two fo them).

Now, I don’t think it is an iFixit issue and their customer service is stellar. I think that given the age of the machine, some of the batteries may be “dated”. Maybe the Late 2013 machine is just old and the batteries that are around now were meant to be purchased long ago… don’t know.

But again, the new battery works fine. I won’t post the link out of respect for ifixit but a quick search on amazon (i got mine from amazon italy) will show a range of batteries around 50 Euros. I got the one with the best reviews…

good luck everybody. BTW the Late 2013 MBP is still a solid machine, I have done all kinds of video editing and color etc and i works great. yes, slower than my new top specs MBP 2019 but hey…6 years old and still competing…

Long live the Late 2013 mbp (with a new battery)"
bert [Entry]

I’m not convinced it’s a battery issue. I’m on my second new battery, reset SMC, calibrated on both and same thing - suddenly goes from like 70% down to 7%. Activity Monitor shows Google Helper using a lot of CPU resources so I’m wondering if it’s a software issue.