Good or bad battery solutions?

[RageCreation]

My friend and I have been planning to bring life into his old Wii system for quite some time. When planning out our Wii Laptop, batteries always seem to be a dead end as neither of us have much experience on the subject. We've done some research and have a few ideas in mind.

1
http://amzn.com/B00935L44E

This is a Li-Po power bank which can output 9v or 12. Judging by it's compact size, and assuming it can be charged while playing, it's perfect. I'd like other peoples' inputs.

2
http://amzn.com/B00RSPMUQW

Very similar to the first. Again, I'd like to know what people think.

3
My final idea is very out of the blue, and will be hard to explain without a diagram

Picture this: Eight Lithium-Ion batteries at 3.7v, 2000mah

Two groups of 4 batteries are connected in series.

Then, the two groups are connected in parallel, thus resulting in 14.8v & 4000mah.

Again, I have no experience in electrical engineering, so sorry if I made you facepalm too hard.

 

[C4RB0]

There are a few things you have to consider when you're looking for a battery. First, the voltage your system needs. Second, how much ampere the system (console, screen, controllers and anything else that's connected to the battery) draws. Third, how much battery life you want to have. And finally, how much space you have in your build.

The Wii is similar to the GameCube and draws around 1A according to the stickies here on modretro at 12V.

Option 1
- 12V: ok
- Supplies 2000mA max: This is going to be enough for the Wii but you also have to consider the screen and so on. Potentially, the 2000mA are not going to be enough to power the whole system.

Option 2
- 10.8~12.6V: The original regulator works with a minimum of 10.2V. This is ok.
- It doesn't mention a max ampere draw. Generally, you should not discharge a li-ion battery at more than 1C. This means that your system shouldn't draw more than 6800mA. This should be more than enough.

Option 3
- 14.8V: I'm not sure if the regulator of the Wii accepts 14.8V. The one in the GameCube did. I assume this is also ok.
- Again, you shouldn't exceed 1C or 4000mA, which shouldn't be a problem.
- It may be better if you make four groups of batteries connected in parallel and connect these four groups in series. You get the same voltage and capacity but it's supposed to be better for balancing the cells. You'll also need a protection circuit and a smart charger to charge the batteries.

To calculate the battery life you can simply divide the capacity of the battery by the ampere draw of your system. For example, 4000mAh battery and 2000mA draw of the system yields 4000/2000=2 hours battery life.

To sum up, all three options should work. If space is not an issue I'd probably choose option 2 since it comes with a charger and isn't limited in the ampere draw as option 1 is. If space is an issue, I'd go with option 3. Something else you have to consider is that manufacturers of battery packs tend to exaggerate the capacity of their battery packs. If you choose option 3, you can be certain that you get the capacity you want.

 

[RageCreation]

I couldn't have asked for a better answer that that. I'll definitely consider everything you said.

To refrain from starting another 'noob thread', What kind of overcharge protection would be on the 2nd battery? Can I feel free to leave something like that charging over night, and charge it while playing?

Thanks!

 

[C4RB0]

I don't know. It doesn't say much in the description. Theoretically, the charger should stop charging when the battery is fully charged. Nevertheless, I'm always very cautious when handling li-ion batteries in my projects. I don't charge them over night and disconnect them as soon as they're fully charged. It's very important that you always use a smart charger to charge them. Option 1 and 2 have some kind of smart charger integrated already.

The battery (i.e. option 2) itself probably doesn't have a protection circuit that allows charging while using it. This means that you either have to make a circuit like this (note you'll only need the left half of it):
viewtopic.php?f=36&t=14089

Or you build your own battery pack and buy a charge managing board:
http://www.batteryspace.com/CMB-for-14. ... -char.aspx

The first option is much cheaper but you'll need a charger for the batteries and a separate 12V power supply for the system. For the second option you'll need only one power supply (18-25V) which charges the battery and powers the system. Unfortunately, it's a bit more expensive. If you go with the second option, you'll also have to make sure that your battery pack fits all the specifications of the charge managing board.

 

[RageCreation]

Thanks so much for the info. This will no doubt be extremely helpful with our project.

 

[Blargaman91]

I saw this thread and thought I would mention that you do have the option of using custom regulators on the Wii. ShockSlayer has a video about it. The advantage would be that you can use batteries with a voltage as low as 7.4v.

 

[Shank]

But Blargaman, didn't we try to but still not figure out how he did that?