• New Patreon Tier and Early Access Content available. If you would like to support AVForums, we now have a new Patreon Tier which gives you access to selected news, reviews and articles before they are available to the public. Read more.

Question about my laptop battery

Carlosmorr

Novice Member
Hi well, I have a question and I would like you to advise me, for laptops in which the battery cannot be removed, how can I extend the useful life of my battery? Since I occupy it almost all day.
 

Kapkirk

Well-known Member
Unfortunately there is not much you can really do, Lithium Ion batteries have a natural life expectancy, ie; they will only allow a certain number of charge-discharge cycles before the capacity to charge is reduced and then ultimately fail.
Some people say leaving the charger in all the time is better than allowing the battery to run right down .
Also keeping the laptop cool will extend the life of the battery, rechargeable batteries do not like heat and will fail prematurely if subjected to too much.
Since most of the heat in a battery is produced when charging from flat gives weight to to idea of leaving the charger plugged in as much as possible. The charging circuit inside the laptop will automatically STOP charging when the battery is full and only top up as you use it thus keeping the battery cooler.
When the battery finally comes to the end of its life you could always find a reliable/reasonable PC/Laptop repair centre and get them to renew the internal battery (it would be fairly easy to do) which will be cheaper and easier than buying a new laptop.
 
Last edited:

MrNismo

Active Member
From research I've done, Lithium Ion battery tech is different to old Ni-M Hydride and Ni-Cd.
The Ni-Cd ones preferred full charge and discharge cycles.
Li-ion doesn't like to be fully emptied or charged to max capacity.

I don't know the optimal charge times but I'll charge at 20% and stop at 90%.

Leaving it connected permanently means the battery is always being topped to max and being stressed.

I'm forever nagging the kids to unplug the charger :lol:
 

Kapkirk

Well-known Member
Unfortunately you are incorrect! Lithium Ion Batteries can be charged in any state, full or half full to maximum or not and will still work just fine without any memory effect. When a rechargeable battery (any rechargeable battery) is full it requires less amperes from the charging circuit to charge it, it will therefore only require mA or even uA's to keep it topped up so will NOT be stressed at all nor will the charging circuit or charger itself.
If you were to run the battery right down, the charging circuit would need to supply between 1 amp and 4 amps depending on laptop model, this DOES stress everything including the battery and charger creating LOTS of heat.
If you don't believe me, feel the temp of your charger after 10-15 minutes when the battery is empty compared to when the battery is full. Note when the battery is full and after an hour or so (with the charger still plugged in) and when the charger has had time to cool, the charger will feel much cooler. I do know what I am talking about so if you don't want to take my advice that is up to you.
 
Last edited:

outoftheknow

Moderator
Further to the above Li-ion batteries are stressed by charging and the stress is greatest above 80% or thereabouts. They also shouldn’t be drained too much - if you trip the internal (low voltage) switch by taking them too far and leaving them uncharged, they won’t charge. Some say you can blast them with a charger and they may come back to life but in the real world we would say they are dead.

li-ion don’t have memory effect but there life depends on the number of charge cycles and that number plummets every time you do a full stress charge. Too up once at 100% wouldn’t add much to the stress or reduce the number of cycles by much at all.

Best advice for Li-ion batteries is to charge between 20- 80% to achieve the maximum number of charge cycles. Some battery management systems built in to chargers and devices mange this for you - especially at the top end of charging.

The majority of Li-ion battery chargers will have at least basic charge patterns that suit that battery type since each battery type works best with different charging behaviour. If you want to charge a 24V battery bank You really need tk k ow the battery type and ensure the charger/battery management suits that type. Same applies with one cell - your device will mange it the best it can :)

However if you simply charge from 1% to 100% every time the battery will do that without memory effect etc issues. That charge cycle will subtract a few (more) cycles from the maximum achievable charge cycles before it is dead though.
 

EndlessWaves

Distinguished Member
Unfortunately you are incorrect! Lithium Ion Batteries can be charged in any state, full or half full to maximum or not and will still work just fine without any memory effect. When a rechargeable battery (any rechargeable battery) is full it requires less amperes from the charging circuit to charge it, it will therefore only require mA or even uA's to keep it topped up so will NOT be stressed at all nor will the charging circuit or charger itself.

No he's correct. Lithium ion batteries maintained at a state of full change will degrade faster than those maintained at lower charge states.

If you look at the electric car results then the problem areas seem to be

1. Topping it up to maximum after every short journey

2. Batteries without cooling systems

Fast charging is generally a non-issue with laptops as they have fairly small power supplies relative to their battery capacity, some won't even be charging at 1C.

So you want to avoid having the laptop plugged in all the time and manage the heat so you don't charge the battery when the laptop is generating lots of heat on it's own.

If you were to run the battery right down, the charging circuit would need to supply between 1 amp and 4 amps depending on laptop model, this DOES stress everything including the battery and charger creating LOTS of heat.
If you don't believe me, feel the temp of your charger after 10-15 minutes when the battery is empty compared to when the battery is full. Note when the battery is full and after an hour or so (with the charger still plugged in) and when the charger has had time to cool, the charger will feel much cooler. I do know what I am talking about so if you don't want to take my advice that is up to you.

While that's true for the charger it's not true for the battery.

As batteries get more charged their ability to take in additional power drops, so at low capacities they can easily take in all the power a laptop power brick can provide and waste little of it as heat.

As they get to higher state of charge they output more heat. Even though the energy going in is lower a much higher proportion of it is converted to heat.
 

The latest video from AVForums

Fidelity in Motion's David Mackenzie talks about his work on disc encoding & the future of Blu-ray
Subscribe to our YouTube channel
Support AVForums with Patreon

Top Bottom