Battery life not what it was

[mlvj]

I ordered my 770 on the day it became available from the Nokia Europe web site.

I have followed the battery instructions pretty well; charge it fully, unplug charger once fully charged, use until battery fully discharged, and repeat.

Until fairly recently we got really good performance - 7, 8 hours between charges; recently that seems to have reduced, so we are recharging once every two or three days.

Is anybody else experiencing this?

Is is time to procure a new battery?

[dino]

Are you using alarms with the OS2006? I played around with the alarms and noticed my battery was taking a hit somtime overnight.

[mlvj]

No, no alarms at all. At the moment we're only using Tabby for web browsing. Sound is turned off and brightness either 1 bar if nighttime, or max of threee if it's in daylight.

[madbob]

My 770's battery died almost exactly 1 year after I got it - early November too.

Reckon I got 300 charge cycles out of it.

Get a new one.....

[TA-t3]

I
I have followed the battery instructions pretty well; charge it fully, unplug charger once fully charged, use until battery fully discharged, and repeat.

I knew Nokia used to put those braindead instructions into their phone manuals, I didn't know they still continued printing rubbish in their documentation.

Those instructions are meant for old NiCd- and NiMH batteries, not lithium-ion batteries!

Lithium-ion (and lithium-polymer) batteries should go through about 6 charge/discharge cycles to begin with, maximum. After that you should keep topping up the battery at every chance you get, this will keep the battery working at full capacity for at least three years. I have experience with both methods (always discharge vs. never discharge), and the former will kill the battery in less than a year, the latter results in a long life time.

Lithium batteries don't like to be fully discharged at all! Don't do it. Whenever you do you decrease the life of the battery.
The only problem with keeping the battery fully charged (that is, around 4.10 volts) is if the battery is also in a hot environment, this will also reduce the life time of the battery. But this is mostly a problem in some laptops, which can get fairly hot inside.

There's a lot of stuff about batteries and how to handle them at http://batteryuniversity.com

[mlvj]

Bugger.

Thanks very much for the response!

[lmf]

How about leaving the Nokia 770 connected to the charger overnight?
Could that damage or reduce the lifetime of the battery?

I assume the n770 has some sort of "smart" battery monitoring that prevents overcharging... so leaving it overnight should not be a problem...
can anyone confirm this?

[lbattraw]

How about leaving the Nokia 770 connected to the charger overnight?
Could that damage or reduce the lifetime of the battery?

I assume the n770 has some sort of "smart" battery monitoring that prevents overcharging... so leaving it overnight should not be a problem...
can anyone confirm this?

Absolutely. It will not damage it at all as all lithium-chemistry chargers must perform precise charge cycles that do not charge the battery any further than a complete charge (or risk a fire/explosion). You can basically leave it connected indefinitely although the battery will tend to self-discharge over time.

Larry

[lbattraw]

I ordered my 770 on the day it became available from the Nokia Europe web site.

I have followed the battery instructions pretty well; charge it fully, unplug charger once fully charged, use until battery fully discharged, and repeat.

Until fairly recently we got really good performance - 7, 8 hours between charges; recently that seems to have reduced, so we are recharging once every two or three days.

Is anybody else experiencing this?

Is is time to procure a new battery?

Yep. It seems that a year is about average for optimal life out of a lithium battery. As mentioned, charging each time you can is a good idea. However much you baby it, the battery will expire on its own without even using it since they have a definite shelf-life; heat will decrease the life quite a bit too.

Larry

[TA-t3]

If it lasts only a year it's because of improper handling. You should get 3 years out of it before you start really noticing any reduced capacity. However, shelf life also reduces battery life time, so if the battery you bought has been sitting a year or two on a shelf in the shop you'll not get what you're paying for.

I also concur with the poster who said that it's safe to leave it in the charger.
For lithium batteries it's critical that they don't undercharge, and extremely critical that they don't overcharge (they may explode!). Because of this there are two safeguards: There is actually a protection circuit inside the battery, it will disconnect automatically when it's fully charged so that the voltage never goes above a certain maximum limit, and it also disconnects when it's about to get undercharged. The latter is a bit inconvenient if it happens, because you may often need special equipment to charge the battery again. But this is when the battery goes all the way down to 2.5 volts or so. Therefore, there's also a regulator in the device itself (in this case, the 770), which turns off the device at a much higher voltage (differs between devices, for a PDA it's often 3.7 volts, for a phone it could be as low as 3.2-3.4 volts, but anyway much higher than the critical 2.5 volt limit). And it stops charging at some maximum voltage level as well.
Incidentally, there are rumours that early Nokia phones left out one of these protectors, if that was the battery protector or the device protector the rumours didn't say, but there were some battery accidents. If this is true or not I can't tell, except that I'm certain all newer devices include the protector. And the only way to find batteries without protector circuits is if you buy "raw" lithium-polymer batteries in bulk, which are mainly sold to RC hobbyists (they assemble them to battery packs for model planes and the like, and add electronics themselves).

Anyway, lithium batteries go quickly to 100% when you charge, but it takes quite a while of additional charging to get to the _actual_ 100%. So leave the device in the charger over night now and then. And as said already, you can never damage anything by leaving it there all the time (unless one or both of the protection circuits are broken.. google 'lithium explode' to see why you don't want to ever experience this..)

[Hedgecore]

I've had my 770 for almost a year now (bought it Dec 19th). I charge overnight, use for an hour or two a day (goes down 1 bar or so) and leave charging all night. Recently I used it for over 4 hours (intermittent internet connectivity, otherwise playing movies on headphones). It went down to 1 bar.

The above is right though, you're supposed to keep topping these kinds of batteries off, not go through deep cycles.

[pdafan]

I know this thread is old, but it's the only one I found on overcharging the battery.

I have been in the habit of leaving my 770 connected to the charger all the time when I'm not using it. Recently I noticed that the back cover wasn't flush with the case any more. When I took it off, the battery popped out on its own!

For some reason it had swollen and now looks more like a marshmallow than a battery - well, it's not quite that bad, but both sides are visibly puffed out, perhaps 1/8" and the battery is thus about twice as thick as it would be normally. It feels spongy, like there is some kind of gas inside it and the plastic casing seals it all in. I could:

1) Puncture the casing and let the gas out so I can at least fit it back into my 770
2) Try to get Nokia to replace it for me, since I think either the charing circuit didn't protect the battery from overcharging or the battery itself is defective. I'd like to go this route if anyone has suggestions on how to do it, but I don't want to spend hours on the phone talking to customer service drones.
3) Get a new battery from ebay. Most likely I'll have to do this anyway. [Update: there seem to be no BP-5L batteries on ebay that aren't sold from Hong Kong! :( ]

Anyone see problems with option 1), the cheap route?

Anyone else had their battery puff up?

[Milhouse]

Contact Nokia IMMEDIATELY!!!

[TA-t3]

Don't puncture the battery! Lithium can start burning when it gets in touch with humidity, even the humidity of the air can be enough!
(Edit: And don't try to use the battery! This is very dangerous.)

There's definitely something wrong with the protection circuitry. Talk to Nokia.
(Edit: Apparently swelling (upbuild of hydrogen gas) can happen because of a defective battery, even if the protection circuitry is ok. In any case, the battery cannot be safely disposed of by normal means, talk to Nokia about the battery and the N800. NB: Sales dudes probably can't be considered Nokia people, for problems like this..)

As for 3): Buy an original Nokia battery, make sure you don't get a fake or a clone. This is the safest way.

(Posting quickly to point out that you MUST NOT puncture the battery. Will edit later if I find the link I had to how to handle it safely.)

[pycage]

I know this thread is old, but it's the only one I found on overcharging the battery.

I have been in the habit of leaving my 770 connected to the charger all the time when I'm not using it. Recently I noticed that the back cover wasn't flush with the case any more. When I took it off, the battery popped out on its own!

For some reason it had swollen and now looks more like a marshmallow than a battery - well, it's not quite that bad, but both sides are visibly puffed out, perhaps 1/8" and the battery is thus about twice as thick as it would be normally. It feels spongy, like there is some kind of gas inside it and the plastic casing seals it all in. I could:

1) Puncture the casing and let the gas out so I can at least fit it back into my 770
2) Try to get Nokia to replace it for me, since I think either the charing circuit didn't protect the battery from overcharging or the battery itself is defective. I'd like to go this route if anyone has suggestions on how to do it, but I don't want to spend hours on the phone talking to customer service drones.
3) Get a new battery from ebay. Most likely I'll have to do this anyway. [Update: there seem to be no BP-5L batteries on ebay that aren't sold from Hong Kong! :( ]

Anyone see problems with option 1), the cheap route?

Anyone else had their battery puff up?


Li-Ion batteries can explode and burn if they're defect. You should replace the battery as soon as possible and never use it in your device!

[Milhouse]

Definately don't puncture it and do contact Nokia for a replacement. They'll probably want to inspect your swollen battery - it's current state could be due to a manufacturing or some other defect.

You'll be doing us all a favour if you can get your swollen battery to Nokia for inspection.

[pdafan]

I think everyone means well in wanting to have Nokia examine the battery and figure out what's wrong. I went ahead and sent an email on the nokiausa.com website, but for the most part getting support from Nokia here in the US is like talking to a brick. I don't even expect a response to my email. The reason is that nokiausa.com is actually run by another company, not Nokia themselves.

If someone has a fairly direct link to someone they know at Nokia, that would be helpful. I haven't heard of any exploding batteries in a 770, but there have been enough recent scandals involving batteries.

In the meantime, here are some pictures for all those who are interested. I can also provide hi-res versions if someone is able to host them:

[Milhouse]

Texrat is probably the closest direct link to Nokia we have collectively. Failing that Thoughtfix seems to do a passable Pope impression and is in direct communication with the God of Internet Tablets (aka Ari Jaaksi).

It might be an idea to keep that battery away from flammable materials until someone more knowledgable from Nokia can advise what to do with it! :)

[pdafan]

Fortunately, my email request for a new battery found the right people! The Nokia Executive Response Team (whoever that is) replied and they are sending me a new battery at their expense with a shipping envelope so I can return the "puffy" battery.

:D

[TA-t3]

That's good news! :-)
But keep a close eye on the 770 when you start charging the new battery, to make sure that there are no problems with the actual protection circuitry in your 770.