eBay

grpcol · ‎05-19-2017

Short summary: Plugged in bike light to charge, battery status looked like barely enough AC power to keep up, later lost AC power while charging bike light, then laptop battery failed. Item: <>

Question: Is this a defect in the battery such that I should request reimbursement, or am I or the bike light to blame?

More info: Laptop battery was working fine up to Thursday, and lasting several hours without charging. I have charged the same bike light before, I am near-sure I charged it on my previous laptop, and it was without a problem. I recall that the computer wouldn't start when it first arrived and required plugging in to AC so I guess battery was empty, not sure if that is normal to store the battery empty.

Long description: I bought this laptop <>. On Thursday night I plugged in a "LifeLine Performance 500 Lumen Front Light" (similar to this one <>), using a micro USB charger which I use daily to charge my mobile. The laptop battery status was every few seconds alternating between displaying up to 240 hours left to fully charge, or "unknown", (at I think 72%,) I assume because just about all (or a bit more than) the AC power was being used up. The battery status was later at I recall 89%, and I switched off the computer and left it on to charge overnight (the bike front light indicated it stopped charging, and from experience power is not drawn from this laptop's USB while the computer is switched off even if plugged into AC). Friday morning I switched on the computer. Within an hour I found that our house had power switched off, and the laptop was dead and wouldn't switch on. About an hour later I plugged it in, and started, battery status was I recall 99%. Since then the battery status is always "Unknown, 87%". It would last a few seconds on battery before losing power, with status saying about 7 hours which is usual for near-fully charged; now it immediately loses power when I unplug AC.

Battery status output: (normally the first line would say something like "Charging, XX%, XX:XX:XX until fully charged")
Battery 0: Unknown, 87%
Battery 0: design capacity 3220 mAh, last full capacity 3247 mAh = 100%
Adapter 0: on-line

Thanks in advance for any advice.

grpcol · ‎05-23-2017

(Oops, found out I'm not allowed to post links to items...)

Sorry my wording was confusing on the bike light.

I will have time later this week to figure this out...

An electrician turned out the power. Laptop was unplugged before power came back on. Adaptor is fine and works with another laptop.

I'm thinking the battery may have been overcharged and gone to "sleep". This was the first time the battery was fully discharged. I'll investigate contacting Acer about it. Thanks for advice given.

repairelectronics · ‎05-23-2017

Not saying this is what happened in your case but it does happen every day;

The standard USB port can supply 5vdc@500ma, if the device that is charging consumes more it can burn out the motherboard power regulators.
Also, anything with a battery or remote power source that is plugged into a USB port needs to have reverse power flow protection or the charging device can send power back into the computer and destroy it, this typically happens when the computer is powered off.

As a side note, you can buy USB devices online that are actually designed to destroy laptops by feeding a high voltage burst back into the computer.

grpcol · ‎05-27-2017

I contacted Acer and they said the computer was originally purchased in 2014 so warranty has expired.

I suspect the bike light did not cause a problem because I have charged it before without a problem, but I guess I can't know for sure.

The seller accepted returning. I'm thinking I could offer to fix it this end to save waste of sending it back, i.e. if I can successful use another battery in this laptop then I can just ask for refund to cover battery.

repairelectronics · ‎05-27-2017

@grpcol wrote:

I recall that the computer wouldn't start when it first arrived and required plugging in to AC so I guess battery was empty, not sure if that is normal to store the battery empty.

Since then the battery status is always "Unknown, 87%". It would last a few seconds on battery before losing power, with status saying about 7 hours which is usual for near-fully charged; now it immediately loses power when I unplug AC.

In my opinion based on what you wrote the battery pack was defective from the start, it should have never arrived 100% flat, unless it was shipped while still powered up. New lithium batteries can hold a charge for 10 years when not in use.

All batteries including wet cells like lead acid car batteries should always be stored in the 100% charged state.

Lithium Ion batteries, unlike Nickel-Cadmium batteries, don't need to be discharged cycled regularly as they don't suffer from "memory effect", as a matter of fact, it can be detrimental to discharge them too low too often.

Keep Lithium Ions topped up whenever possible, there is nothing wrong with charging them even at 90% full, this actually can make them last longer.

Try disconnecting power adapter, remove battery, then try to power up the laptop without battery - disconnect power again and reinstall battery, reboot and see if the weird charge state percentage go back to normal.

grpcol · ‎05-27-2017

@repairelectronics wrote:
In my opinion based on what you wrote the battery pack was defective from the start, it should have never arrived 100% flat, unless it was shipped while still powered up. New lithium batteries can hold a charge for 10 years when not in use.

All batteries including wet cells like lead acid car batteries should always be stored in the 100% charged state.

Lithium Ion batteries, unlike Nickel-Cadmium batteries, don't need to be discharged cycled regularly as they don't suffer from "memory effect", as a matter of fact, it can be detrimental to discharge them too low too often.

Keep Lithium Ions topped up whenever possible, there is nothing wrong with charging them even at 90% full, this actually can make them last longer.

Try disconnecting power adapter, remove battery, then try to power up the laptop without battery - disconnect power again and reinstall battery, reboot and see if the weird charge state percentage go back to normal.

Yep, tried doing those steps: switch off, remove battery, switch on and off, replace battery. Battery says "unknown", 86%.

(Also pressed the battery reset button but probably doesn't matter having already removed battery.)

Funny thing is though, the battery was working perfectly for I think a couple weeks up to the day before it failed. I recall reading lithium batteries can start in a discharged state before initial charge; (the protection circuit kicks in after initial charge to disable the battery if the charge gets too low, e.g. if you "fully" discharge and never charge then the battery loses even more charge over time and can get so low it makes it unsafe to recharge, so protection circuit disables battery.)

I was hoping I could find an old laptop with compatible battery, but they seem to all have different shaped connections and voltage, so don't see much hope in that... (this laptop is an Acer Aspire with 15.2V battery).

The laptop was cheaper than others listed, so might be worth me buying a new battery to test even if might not work and come out of my own pocket. I will probably buy another of same model if return, so spare battery could be handy.