Clara battery dies at 46%

[RodRiquez]

Hi there,

My Clara HD runs out of battery at 46%.

Without warning, when the battery level gets to 46% the device immediately turns off. I am unable to turn it back on or reset it.

If I connect the power cable, the device comes back on after a minute or two. If the battery level then says, for example, 48%, once it gets to 46% it will shut off again.

My Clara HD is 3 years old. Software 4.38 (up to date)

Does the mean the battery needs replacing?
3 years seems like a short lifetime for a device battery, is this normal?

[Aleron Ives]

How often does this happen? Kobo has notoriously inaccurate battery meters. If the device shuts off and then says 48% the moment you plug it in, the meter is definitely not calibrated properly. Charge it for a few hours and see if the meter drops properly when you start from 100% full.

[RodRiquez]

I cant say how often, really its just started but I do remember finding it had gone dead at other times when there seemed to be plenty charge. It could well be the metre as you say.

Ill give what you suggest a try & report back.

[rcentros]

Originally Posted by RodRiquez

I cant say how often, really its just started but I do remember finding it had gone dead at other times when there seemed to be plenty charge. It could well be the metre as you say.

Ill give what you suggest a try & report back.

If it turns out it's the battery, it looks like they can be bought here...

https://batteryint.com/products/3-7v...91ca47ea&_ss=r

I don't know where these ship from, or what the cost is for the shipping.

[RodRiquez]

Originally Posted by Aleron Ives

How often does this happen? Kobo has notoriously inaccurate battery meters. If the device shuts off and then says 48% the moment you plug it in, the meter is definitely not calibrated properly. Charge it for a few hours and see if the meter drops properly when you start from 100% full.

OK. So the battery suddenly died again & here is what I observed.
- I charged it fully after your comment.
- I used the Clara HD each evening & the battery went slowly down.
- a few days ago it was on 52% & I thought "well it'll get down to 46% soon & ill see what happens."
- I didnt pay specific attention, but 2 evenings later the Kobo suddenly shut off.
- I immediately connected it to USB charge & when it booted up it said 9% battery.

So this time it seems a little different with the battery readings, but similar in that close after 50% it shut off.

Does this seem like a battery replacement issue?

[SilentPartner]

One good thing with the new Kobo is the repair kit from iFixIt.

Not sure if you could replace the battery in this Clara?

[Aleron Ives]

Originally Posted by RodRiquez

- I didnt pay specific attention, but 2 evenings later the Kobo suddenly shut off.
- I immediately connected it to USB charge & when it booted up it said 9% battery.

This actually sounds like it might be a little progress. It says 9% when you plug it back in, rather than 49%, so it seems like the Clara is finally starting to realise what the actual charge level is. I would charge back up to 100% and do another test. My guess is that this time it will shut off when it reaches 10%, rather than 50%, so the meter is slowly giving you more accurate numbers.

My Libra did the same thing when it was brand new; I had to do this process 2 or 3 times before the battery meter started reporting semi-accurate values. (My Libra would suddenly shut off at around 30%, rather than your 50%.)

[RodRiquez]

Thanks. OK, ill give this a try.

Mine isn't new though, its 3 years old & this problem is more recent. When I bought it the battery metre seemed to work normally 100-0%

I use it everyday, but only for a short time 30-60 mins & I have the backlight on very low (8%)
It used to last 3-4 months. Now just 1 month.

[Aleron Ives]

Yes, the purpose of calibrating the meter is to get an accurate idea of how much charge you have left and how long you can go on a single charge.

My guess is you've been charging to 100% and leaving it there for long periods since you don't read very much, and that's caused the battery to degrade. Once the meter is calibrated and you have a better idea of how long the battery will last in its current state, you can decide whether you want to continue as is, replace the battery, or replace the device.

[RodRiquez]

I use the reader every day, without fail, for about 1 hr. I never leave it connected to USB when charging is complete & I only charge if I notice it is low. I also always make sure I put it to sleep when finished using.

[Quoth]

Leaving any LiPoly cell based gadget made in maybe last 15 years connected doesn't degrade the battery. The built in charge management stops charging it or it would go on fire.

[JSWolf]

Originally Posted by RodRiquez

Thanks. OK, ill give this a try.

Mine isn't new though, its 3 years old & this problem is more recent. When I bought it the battery metre seemed to work normally 100-0%

I use it everyday, but only for a short time 30-60 mins & I have the backlight on very low (8%)
It used to last 3-4 months. Now just 1 month.

If you cannot get the battery meter calibrated, then you will need to open it and replace the battery. Where is it you live so someone can recommend a battery for you if that's what you need.

[Aleron Ives]

Originally Posted by Quoth

The built in charge management stops charging it or it would go on fire.

We're not talking about overcharging here. Lithium-ion batteries don't like being fully charged or discharged, and keeping a battery at > 80% for long periods will cause the capacity to drop over time. I ruined many phone batteries this way. Now that I know about keeping the charge level between 30-80%, I've had the same phone battery for four years, and its capacity hasn't really declined at all.

The capacity decline RodRiquez has described over the last three years is exactly what you'd expect from putting the battery through full cycles. The purpose of calibrating the meter is to see just how much the capacity has declined. Current evidence suggests > 50% decline, but since an e-reader uses little power, the Clara may still be usable with a degraded battery -- provided the meter will provide accurate numbers to indicate when the Clara needs charging.