C270 battery questions - Chromebook

greatnw

I have an Acer c720 Chromebook that I picked up super cheap. I can usually solve most problems. So far no go on this battery issue. When I first started at least it saw the battery and it was stuck on 1% with the blue light on indicating full charge. I believe I tried all of the reset combinations and nothing worked. So I disconnected the battery and now the unit doesn’t see the battery at all. BTW, When the battery was disconnected I fired it up and the amber charging light would come on. As soon as the battery was back in only the fully charged blue light would display.
A couple of times when I did the reset button power button for 10 seconds that charging light would briefly turn amber and immediately go to blue.
Any other ideas?

billsey

Sounds like the battery has gotten too low to recharge. Luckily they aren't too awful expensive to replace, in the $20-30 range IIRC.

greatnw

I was thinking the same thing but the hardware on this unit is new to me and the battery issue seems a little crazy that the voltage could get too low to be charged.

Thanks for responding!

billsey

It's a common feature of the lithium-ion batteries, when they were new there was lots of issues with them getting way to hot, even catching on fire on occasion. This was due to the extra heat when charging from very low, along with the habit of growing lithium 'whiskers' internally during the discharge process. The solution was to make the batteries a little smarter, and to shut them down if they got into the risky area. In normal use it's actually really hard to get them discharged to the point where they can't be recharged, since the power management shuts the system completely off while there's still charge (5-10% typically) still left. But you know how it goes, 'really hard' and 'doesn't happen' are two totally different concepts.

(The whiskers, BTW, are the reason why some batteries start bulging, the whiskers penetrate the layers between cells and the electrolyte migrates around...)