I have a i931x Lasonic that I wanted to make portable so I purchased 10 Alkaline batteries and took it out to play some tunes while I washed my car. Next me and a few guys shot some pool while it played in the background not loud in either situation and using SD Card only. Then it dies! Not even 1 day. Hold on....it gets worse!

I decide to purchase rechargeables. I get NiMH 3,000 mah batteries and charge them for 6.5hrs  at 470ma (which is about right when you do the math). It swallows these batteries like a dog being thrown it's favorite treat! It played 4 songs loudly and then fizzed away to no volume at all. One thing I did notice is there is a big defference in the amps power output when using rechargeables. Mine seemed to hit harder. It was flexing the AM/FM logo strip at the top at max volume and had slightly more kick to the beats of songs.

I'm currently waiting on a new set. This time I went with the highest capacity I could find. These are 10,000 mah batteries with the charger charging at 1300ma for 7.5hrs. 

Has anyone tried these? Do they hold up?  I hope because 10 batteries and 1 charger is worth more than the box! Of course I know I will save money over time. There is not a circuit board in this thing thats bigger than a credit card. Im using this thing with SD cards not ipod so what the heck could be pulling all that power?  I guess it has to be the massive 12Wx2 power plant because there isn't even a motor like my true vintage boxes and they last way longer.

Thanks for any input.

Don't feel to bad .. My JVC PC-55 will make it through about 5 songs before the batts are dead . Portable ?  Ya right ! 

Well I am happy to report that the new Tenergy 10,000mah Batteries are the way to go for our battery hungry devices. I purchased the V-9688 Charger combo with 8 D Premium Tenergy 10,000mah batteries and then added 2 more to complete the set for my stereo (since it takes 10). The charger has a discharge function so I started off by letting it fully discharge then recharge each one. I plan to discharge after every 4th charge to avoid memory. These are Ni-MH but I have been doing a bunch of reading on this and Ni-MH batteries can develop a memory over a period of time (especially in chargers which are not smart chargers).

This is my first charge cycle and I am putting these batteries and my i931x through its paces. I know Im being cruel to both the stereo and the batteries but I perform tests of everything I own. This will never be done again but I just need to know under the worst case scenario how both will hold up to a little abuse. I have turned the stereo up full blast using a SD Card with over 10 hours of music on it in the basement. That was at 10:10 am. At 3 pm it is still thundering away. The back of the stereo is warm but the batteries are keeping their cool.

My wife couldn't take it anymore and I was forced to abort my high stress test. I moved to the house and used cleaning the house by listening to my music for motivation as an excuse to continue playing the stereo. My wife happily agreed as long as I played songs she liked and continued to clean :-) Im happy to report that the house is squeaky clean and Im quitting before the batteries or the stereo.

I'm happy and my wife is happy...lol A win win situation. Best 100 bucks I've spent. 

I'll keep you guys posted.

Thanks for the stress test. Good to know regardless which box should I ever plan on getting recharge batts.

I took my wife out for dinner and left it playing in the kitchen half volume. Im turning it off because Im going to bed. Im giving up! I never expected them to last this long. Never had batteries that last longer off the charger than on it. They're better than disposable Alkalines.

I personally recommend them. We'll see how they hold up after several hundred recharges....if I ever get to charge them again.