Replacing old gigabeat battery: Ipod 4G (1200 mAh) vs Gigbeat F40 (1000 mAh)

[GigaBrick]

I've seen some of the run times here... http://www.rockbox.org/wiki/GigabeatRuntime

As well as the 30 hour bench that was posted along with the tutorial on how to mod the Ipod 4 g battery...  http://www.rockbox.org/wiki/GigabeatBatteryUpgrade

Well, I tracked down a couple versions of that battery on eBay and found they were rated at 1200 mAh.  Then I also found a battery from the same manufacture that was made for the Gigabeat series that is 1000 mAh.

So, would the Ipod battery likely give me a significant increase in battery life?  There doesn't really seem to be a lot of difference between 1000 mAh and 1200 mAh.  There's not really enough people mentioning which battery they used for me to really draw a solid conclusion but if I could assume the ones left blank are using the default battery, then the ipod batteries don't really seem to have that much of an edge.  One 19 hr bench was even reportedly using a 830 mAh battery...  So I'm even left to wonder how much it depends on usage, especially seeing a couple of results for the Ipod battery at only 15-20 hours.

In any case, it doesn't seem like it would be that complicated of a job to modify the Ipod battery but unless I'm actually going to be looking at a difference of 5 or 10 hours I don't think it's really worth it.  Maybe I missed the point and the modification is just if you weren't able to find an original battery replacement?

[torne]

The increase in battery life will be 20%, give or take a tiny amount. That's what the capacity number means. So, it won't give you 5 hours more life unless your current life is 25 hours already.

[GigaBrick]

The increase in battery life will be 20%, give or take a tiny amount. That's what the capacity number means. So, it won't give you 5 hours more life unless your current life is 25 hours already.

So given that, if I got the figure on the left for the 1000 mAh I could estimate that I would get the time to the right of it with the 1200 mAh at a 17% increase?  Give or take a little...

1000 mAh   1200 mAh
25hrs           30hrs
20hrs           25hrs
16hrs           20hrs
12hrs           15hrs
10hrs           12hrs


That seems to match up with some of the numbers I'm seeing on the table there.  Since 16 hours doesn't seem like an unrealistic estimate then I could probably look at it as a matter of 16 vs 20 hours...   Well, that makes my decision a little easier, I think I'll just go with the original battery at first and if I wind up only getting 10-12 hr battery times then I'll look into the Ipod battery.

Thanks