Voyage or Oasis?

[JSWolf]

Speaking of the battery, the battery in the Oasis is going to last roughly 1/2 the time of the Voyage because it will need to be charged more often.

As for the designs, (IMHO), the Voyage is a better design and from what I have read here on MR, the light works better on the Voyage. Less complaints from owners.

[jbjb]

Originally Posted by JSWolf

Speaking of the battery, the battery in the Oasis is going to last roughly 1/2 the time of the Voyage because it will need to be charged more often.

It has already been explained to you in other threads that the reasoning which leads you to that conclusion is fundamentally flawed, so I don't understand why you persist in making that claim.

[John F]

Originally Posted by jbjb

It has already been explained to you in other threads that the reasoning which leads you to that conclusion is fundamentally flawed, so I don't understand why you persist in making that claim.

Could you provide a link please? I don't recall any explanation other than (paraphrase): "calculating battery life is too complicated, so don't worry about it"

And Jon's "1/2" seems conservative to me since the Oasis battery size is 1/5? the size of the Oasis's, depending on use

[jbjb]

Originally Posted by John F

Could you provide a link please? I don't recall any explanation other than (paraphrase): "calculating battery life is too complicated, so don't worry about it"

And Jon's "1/2" seems conservative to me since the Oasis battery size is 1/5? the size of the Oasis's, depending on use

Here's one.

There are several similar posts in different threads which all make the point that claiming a reduced battery lifetime for the Oasis as fact is unjustified.

[John F]

Originally Posted by jbjb

Here's one.

There are several similar posts in different threads which all make the point that claiming a reduced battery lifetime for the Oasis as fact is unjustified.

Thank you for the link.

Since we are dredging this up again, although it may not be fact, IMO, it is more likely than not (depending on usage patterns, and especially (I'm guessing) on the usage patterns of some (typical?) MR members).

If nothing else, provide people with "the facts" (battery size, expected life for different usage patterns, ...) so they can make an informed decision if they are concerned.

YOMV.

[jbjb]

Originally Posted by John F

Since we are dredging this up again, although it may not be fact, IMO, it is more likely than not (depending on usage patterns, and especially (I'm guessing) on the usage patterns of some (typical?) MR members).

If nothing else, provide people with "the facts" (battery size, expected life for different usage patterns, ...) so they can make an informed decision if they are concerned.

It's clearly perfectly reasonable to point out a concern that more frequent charge cycles, all other things being equal, could reduce lifetime, just as it is reasonable to point out that all other things aren't, in fact, equal and shallower charge cycles, reduced peak charge levels and other design decisions could increase lifetime.

What is unjustified is to claim, as Jon has done repeatedly, that the overall net effect will certainly be a reduced lifetime - we simply don't have enough detail to make such a claim and to do so is misleading.

[radamo]

Thanks all for the feedback. Much appreciated. I am going to stick with the voyage since it does all that I could want and I don't want to risk getting a worse screen (the voyage is very nice) if I took the chance to switch.

[barryem]

Originally Posted by DaveFalcon73

Actually Barry this is one of those myths that a lot of people don't quite understand how the battery life cycle works. Most Lithium-Ion batteries are quoted as lasting 400 charge cycles not 1000 charges. A charge cycle is defined as charging the battery from 0% to 100% then discharging it back to 0%. After that 400 or so charges then you'll expect only about 80% capacity of the original battery, losing 20%, ultimately not lasting as long as it previously did. Every Lithium-ion battery has these whether it's a Kindle battery or an iPhone or Laptop battery.

Charging under regular use (topping up) does not count as a charge cycle or even a significant part of a charge cycle.

The website The Battery University has been around for years and is commonly given as a reference in battery matters. They have a very good reputation for reliability. Here's a link to one of their many articles about lithium ion batteries:

http://batteryuniversity.com/learn/a...ased_batteries

I think you'll find it useful reading.

Barry

[John F]

Originally Posted by jbjb

It's clearly perfectly reasonable to point out a concern that more frequent charge cycles, all other things being equal, could reduce lifetime, just as it is reasonable to point out that all other things aren't, in fact, equal and shallower charge cycles, reduced peak charge levels and other design decisions could increase lifetime.

What is unjustified is to claim, as Jon has done repeatedly, that the overall net effect will certainly be a reduced lifetime - we simply don't have enough detail to make such a claim and to do so is misleading.

Sure, there are going to be uncertainties. But than why point out: "...things aren't, in fact, equal and shallower charge cycles, reduced peak charge levels and other design decisions could increase lifetime..."; this could equally well be applied to the Voyager, so again, all things being equal...

Batteries. Oasis: 245mah, Voyage: 1320mah.

[Dr. Drib]

Originally Posted by JSWolf

Speaking of the battery, the battery in the Oasis is going to last roughly 1/2 the time of the Voyage because it will need to be charged more often.

As for the designs, (IMHO), the Voyage is a better design and from what I have read here on MR, the light works better on the Voyage. Less complaints from owners.

What a world of difference 4 little letters can accomplish.

Thanks, Jon.

[jbjb]

Originally Posted by John F

Sure, there are going to be uncertainties. But than why point out: "...things aren't, in fact, equal and shallower charge cycles, reduced peak charge levels and other design decisions could increase lifetime..."; this could equally well be applied to the Voyager, so again, all things being equal...

The point is that the two-battery design of the Oasis+case can be seen as encouraging usage patterns which result in shallower charge cycles, and similarly could make some battery lifetime extending design decisions more feasible than is the case with the Voyage.

[John F]

Originally Posted by jbjb

The point is that the two-battery design of the Oasis+case can be seen as encouraging usage patterns which result in shallower charge cycles, and similarly could make some battery lifetime extending design decisions more feasible than is the case with the Voyage.

Or they may be limited by the two battery design. They may be doing ultra quick charges to ensure that the small battery is ready to be used when it is disconnected from the cover?

How about if you read 5 hours a day, with similar usage patterns for a Oasis and Voyage: reading without covers, charging at the end of the day. How would you expect the life of the batteries to compare?

I'm guessing the average user isn't going to stop and think about quick charge vs slow vs deep vs shallow, ...

IMO

[jbjb]

Originally Posted by John F

Or they may be limited by the two battery design. They may be doing ultra quick charges to ensure that the small battery is ready to be used when it is disconnected from the cover?

That seems unlikely to me, but you're right - we don't know.

How about if you read 5 hours a day, with similar usage patterns for a Oasis and Voyage: reading without covers, charging at the end of the day. How would you expect the life of the batteries to compare?

That seems to me like an unlikely usage pattern for an Oasis - certainly my usage pattern (and that of everyone else I know with an Oasis) involves returning the Oasis to its cover between reading sessions.

But, again, we don't know.

Bear in mind - I'm not the one making any claims here. I'm not saying the lifetime will be better, or worse, just that it's not obvious that it will be worse and those people claiming that it definitively will be are basically guessing and then trying to pass that guess off as established fact.

[JSWolf]

The battery inside the Oasis is smaller than the battery inside the Voyage. It's been said to be 1/5th the size. But let's just go for 1/2 the size for this example. We know a lithium-ion battery can be charged X amount of times. Let's say 500 times. Now if you charge the Voyage 500 times you get twice the life of the Oasis where 500 times would be 1/2 the time.

Now, in reality, the Oasis battery is 1/5th the size so it could very well be less than 1/2 the time of the Voyage.

Now if anyone can prove I am wrong, please do so in this thread.

[HarryT]

Lithium batteries have two limits:

1. The number of charge cycles.
2. Increasing resistance of the cells with the passage of time.

For a high-current laptop battery, factor 1 will dominate and it's the number of charge cycles that'll determine the lifetime of the battery. For a low-power device like an eink reader, though, it's vanishingly unlikely to reach anything approaching its cycle limit before the battery dies of old age (which will typically occur in around 5-7 years).