I need new batteries for my older acer notebooks

I have a 4810 and 7720 that needs new batteries. I was looking on ebay and there are some there that supposedly have more capacity than the originals. Is this a load of crap, or do they really work? if they do, I am going to pick up two high capacity batteries.

 

If a battery is advertised with a significantly higher capacity than the original, it has to bulkier than the original and also heavier.
The only way to achieve higher capacity is to include more cells and they take place and add weight (that is unless completely new cell technology hits the market but that's not where we are now).

So if you are offered an extended battery that says 4600mAh instead of 4400mAh - that might be OK, but it someone is advertising say 8800mAh and the battery is not significantly larger and heavier than the stock one, it's a lie.

 

Depends on how they optimized use of the battery space. I recently upgraded my Acer E11 from a 30WHr to a 45WHr battery only because they didn't use all of the cell space with the 30Whr, it was just replaced by a plastic bracket instead.

 

True but E11 has a very different type of battery. Both notebooks owned by kojack use the old type - plastic box full cylinder shaped cells.

Battery for 7720 looks like it could fit 8 cells - two rows of 3 and one row of two. Service manual confirms that there were two batteries available for this notebook- 6 cell and 8 cell. 6 cell - as you said - would have not used all the place - the narrower part of the battery would be free. 8 cell battery would have used it all.

6 cell battery was 4000mAh; 8 cell was 4800mAh. So a single cell would be 667mAh for one and 600mAh for the other. It stands to reason that using 8 cells 667mAh would easily get you some 5300mAh battery without increasing the size.

Since 866mAh cells of this size have been available and reasonably priced for a while now, one could expect 6 cell standard size battery for 7720 to be advertised as 5200mAh (there are lots of those); potentially 8 cell advertised as 6900/7000mAh (haven't seen those) and these could be normal-size.

To get above that you'd need an extended battery. This one for example is a real deal - it's advertised as 12 cell 10400mAh. That would indeed bring a single cell to 866mAh. What's more you can see that it's not a regular shape - it has a bulge that looks conveniently exactly like 4 standard cells - that is on top of those 8 that fit within the normal sized battery.

That would indeed mean 12 cell - 10400mAh battery.

Please excuse the math - I know there are different sizes of cells and different capacities of cells but if you look at the battery like that, you know what size of cell is most likely used and if you know what capacity cells are most often used these days you can approximate the result. Point being - 5200mAh normal size and 12 cell 10400mAh (raising the back of the notebook) both seem plausible enough as "extended batteries". That is on top of 4000/4400/4800mAh "standard" batteries.

Same type of approximation can be done for 4810.

 

As far as I can tell, the batteries are physically bigger. The one for the 4810 raises the back of the notebook a little bit compared to the stocker. same for the 7720. So, maybe its a safe bet that they are actually higher capacity than the originals. right now I can get less 3 hrs from my timeline and about 1.3 hrs from my 7720. where as when I installed my ssds in both, I was getting 11-12 hrs from the 4810 and about 6-7 hrs from the 7720. So its new battery time!

 

Well, I just noticed something. Using edge, My battery would drain very fast. I switched back to IE to get rid of the slow ad bombardment that is happending in edge. and I am now at 51% on my battery with 3h 57min left on my timeline. I will still refresh my batteries, but EDGE is a battery HOG.

 

I just looked. The 9 cell for my timeline is 30 bucks shipping included. I will get both batteries anyways. No big issue. That along with the big battery for my 7720, I should be good for another while.