'Built-in' Li-ion batteries, the eternal question

[Bup]

Hi .

I'm contemplating getting an a608 (2Gb flash with loong battery life)..but I've always had this distinct disliking towards 'built in' batteries.

I've attempted to research this a bit, but I cannot seem to get it entirely straight. Will li-ion batteries finally degrade to around 1% of original capacity? Does this take 3 years or 30?

http://www.batterygeek.net/lithium-ionbatterypacks2.htm has a good chart- but what about 1year+?

Furthermore, has anyone ever attempted to change the battery of a e-4/507? Can identical batteries be acquired somewhere, even?

[MDX-400]

As you can see from the chart there Li-Ion is majorly affected by temperature, particularly when it is at full charge and not in use.

Higher temperatures kill off Li-Ion cells probably more than anything else--this is pretty much why you see a lot of laptop batteries failing* after a year or two of service. Because laptops tend to run hot and people tend to leave their batteries in them all the time, even when they have them plugged into the AC with the laptop perhaps running for hours. From the above, you can see how this is the worst situation for the battery.

*When I say "failing" I don't mean they stop working completely but capacity is markedly reduced.

The other thing I would also mention is that Li-Ion has what I refer to as "anti-memory" (this isn't a real term it is just the way I refer to it). In other words where chemistries such as NiCad and NiMH (to some degree) suffer when you don't discharge the battery fully, Li-Ion works the opposite way. With Li-Ions they suffer when they are discharged fully, so you'll want to keep the battery topped up as often as possible. Plugging it in to charge everyday or two, or before you get to half capacity is a good idea. This is not to say don't use the battery to full capacity if you want to or need to ever but just don't make a habit of it.

Lastly we have charge cycles... Batteries also begin to wear/"fail" after so many charge cycles. So there are a few avenues where wear occurs--hopefully this points out to you that as you use the battery it is going to suffer wear one way or another.

With proper care, the battery should last a good while. As for replacement the thing they usually don't tell you is that Li-Ion batteries, particularly the Li-Ion-Polymer type, typically are manufactured in similar sizes for all sorts of applications. Where the "internal" batteries in these units can easily be purchased from Sony, the cost of the "internal" ones are usually high. However if it is using a Li-Ion-Polymer battery (or even a standard Li-Ion which connects internally with wires instead of contact points), all you need to do is find out the size of the battery (by dismatling the unit) and you can pretty much get a replacement from any supplier of such cells (Japanese or American cells are recommended). Li-Ion-Polymers usually have the exact dimensions right in a number printed on the pouch... A battery labelled as "VP383562A" would represent a Li-Ion-Polymer of 3.8mm thickness, 35mm wide and 62mm long, for example. Match the dimensions and you can usually easily get a replacement and at significantly less cost than buying the part from Sony.

As an example, that VP383562A battery is the one found in the MZ-E95 MD unit. It actually uses two of those cells in parallel. The replacement cost for the two cells from Sony is over $100 US; the cells on their own can be found for around $12-$15 each, making a replacement as cheap as $25...

[Bup]

Thanks for your ver informative reply Edit. Omg (haha), <-- that smiley almost makes me reconsider anything Japanese!! I dare not do the tongue-smiley!

I understand that all rechargable batteries will die after so many charge cycles, and also that li-ions can deteroiate in other ways; or through other means rather, than simply charging and draining. It's also good news to hear that it is potentially possible to find a replacement 'internal' battery, once one starts fading. (80% after 1 year at typical usage? Would that be 60% after 2 years? 50?)

I don't entirely understand this: "

Where the "internal" batteries in these units can easily be purchased from Sony, the cost of the "internal" ones are usually high. However if it is using a Li-Ion-Polymer battery (or even a standard Li-Ion which connects internally with wires instead of contact points), "

Does this mean that some internal li-ions that sit in Sony players are connected via contact points?

Anyway, are the E4/5/A6 series of flash players equipped with batteries that would be potentially exchangable(pure li-ion or li-ion-polymer with wire connectors), do you know?

Edited February 11, 2006 by Bup

[Guest Stuge]

?Anyway, are the E4/5/A6 series of flash players equipped with batteries that would be potentially exchangable(pure li-ion or li-ion-polymer with wire connectors), do you know?

I wiil not suggest you to replace the fading battery with some other kind of battery .Exchane the old battery with Sony original battery only.

Wires of battery in E400/E500/A600 are not soldered they are attached using small socket .So we can exchage the battery ourselves if we can find the battery easily .

bTTERY OF E507 IS FOR ABOUT $112

here

http://jandr.partsearch.com/product.asp?is...oldInventoryID=

[MDX-400]

Does this mean that some internal li-ions that sit in Sony players are connected via contact points?

I'm unsure actually. Because if the unit is using a Li-Ion (not Li-Ion-Poly) battery then it likely would use some kind of contact points though they might actually be soldered in place (as opposed to being readily removeable as a "removeable" battery would be.) However I'd speculate that nearly all internal batteries would by Li-Poly and therefore use either soldered wires coming off the battery pouch or wires terminated in a small connector, connecting to the board.

I wiil not suggest you to replace the fading battery with some other kind of battery .Exchane the old battery with Sony original battery only.

bTTERY OF E507 IS FOR ABOUT $112

I fail to see why you'd have to follow buying only a Sony original battery? If you go with a Japanese or American made cell you should be fine. Chinese cells aren't that great for the most part, I'd have to say, but then again a lot of big companies are using MIC Li-Ion cells anyway since they are cheaper. I woudn't be surprised if Sony were using outsourced MIC Li-Ions themselves, in some devices, instead of using their own Japanese cells.

Provided the cell is of good quality and of the same or higher capacity you should be fine. The Li-Ion chargers all work in the same way these days and you should be safe replacing with any Li-Ion cell of similar dimensions and capacity.

In fact you might even be able to find a battery from a supplier that Sony themselves use, only buying the cell(s) somewhere other than Sony can cost you as little as 1/4 the price. Why pay nearly the cost of your entire unit just to replace the battery? If you're going to do that you might as well just buy a new unit!

If you are buying the cells from a bulk supplier/store of these types of cells usually you just get the pouch (again talking about Li-Ion-Polymer) alone and have to solder on you own connections--you could easily remove the connector from the old battery and connect it to the new one. Keep in mind there is a special solder flux and procedure that must be used to connect wires to a Li-Poly battery. Alternatively a lot of places will make a cell/battery with the connector you need all soldered and ready to go.