Battery Help needed please

[Brownie]

Hi everyone, i need a little help

I was looking at batteries for my portable and literally have no clue.
All i know is i want lithium ion or polymer.
I think a battery pack would be better for me as its simpler.
Would this battery pack be okay, is it a good one?

http://www.ebay.co.uk/itm/RC-Multistar- ... 418ecfb33f

Another question. Can you run a gamecube on 11.1v without a custom regulator.
Also will a 12v screen work with 11.1v, or will it just not turn on at all.
Heres another battery pack, thoughts..?

http://www.overlander.co.uk/batteries/l ... sport.html

Any suggestions to battery packs would be really appreciated.

 

[The_Next_Guy]

The GC regulator will work down to 10.1V or something close. You wouldn't be able to use the batteries to their full capacity. I recommend using a 14.8v pack. Asfor the screen it depends. If you are using a cheap ebay screen you probably will be able to but you shouldn't run the screen directly from the batteries.

 

[Brownie]

Thanks for that. I think i will just use a 14.8v pack and use a regulator to step it down to 12v.
What do you think about the battery case in the 1st link? Any good?

 

[The_Next_Guy]

It looks ok to me. you only have to regulate the display's voltage because the gc can accept upto something like 20v

 

[Brownie]

Okay good to know, thanks.
One last thing. How long do you think the charge will last?
Its 14.8v, 8000mah. It will just be powering the standard 12v screen and the motherboard, as well as the WASP fusion, some iLuv speakers and 1 maybe 2 small 3v fans.

Any idea?

 

[The_Next_Guy]

Well total watts equals 118.4. The gc raw draws 36. The display will most likely draw 2-3. Fans maybe 2-3. If your going without the disc drive but with a wiikey/wasp that takes out a good chunk of power consumption. I don't know how much but ill say you will probably get 3-4 hours. Just make sure the battery is legit.

 

[Pinotte]

This battery is 142 x 49 x 43mm in size, which is very big for a portable.

 

[The_Next_Guy]

Yeah I kinda thought that too

 

[Mooper]

I wouldn't use that battery. It has a peak discharge of 20c and a constant of 10c. It can put out 80-160 amps. Way overkill for a portable. A lower discharge battery will generally be smaller as well.

This wouldn't be any easier than building a battery pack either, as you would still have to cut off the balance lead connector and solder the balance leads to a protection pcb.

Unless you plan on making the battery removable and using a balance charger.

 

[Brownie]

Can you suggest any good batteries to wire together that make 14.8v and a decent mAh.
Or a good battery pack (14.8v and decent mAh).

I literally have no idea when it comes to batteries and its the only thing holding me back from finishing my portable.

Would 4 of these wired together be any good?

https://www.all-battery.com/4pcsLi-ion1 ... 39170.aspx

Everything seem okay?

 

[The_Next_Guy]

I think most modders use those batteries, they last a good 2-3 hours

 

[bentomo]

Those one's won't do unless you use a battery mounting system. You need to have tabs spot welded onto your batteries if you want to be able to solder to them, plus you'll need a proper protection circuit.

Those batteries have the PCB built in and are designed to be stand alone cells so you wouldn't be able to properly charge them as a 14.8v pack.

You need 4 of these.

http://www.all-battery.com/tenergyli-ion1865037v2600mahrechargeablebattery-30005.aspx

Plus a protection circuit.

http://www.all-battery.com/PCBfor4Cells14.8VLi-ion_Li-PolymerPacks6AWorking17Acut-off-32027.aspx

Plus a charger.

http://www.all-battery.com/universalfastsmartchargerforli-ionli-polymerbatterypack148v4cells-2.aspx

Then you would wire this together using the guide in the protection circuit and with the play and charge diagram listed here on the forum.

http://forums.modretro.com/viewtopic.php?f=36&t=14089

The diagram is similar with those who are using a stock regulator like yourself. It should be pretty straight forward.

 

[Cllinw]

Just wondering, how long of battery life do you think 4 of those at 14.8v will give?

 

[Brownie]

Thanks for the detailed response.
Theres one problem. Im in the UK and all battery.com charges a lot for shipping.
I have to use batteries.co.uk and i have found these. Would using these instead of the ones you provided work if i do everything else you said to do.

http://www.allbatteries.co.uk/lithi...ttery-ncr-18650b-3-7v-3350mah-ft-acl9037.html

 

[bentomo]

Possibly, but you still need the option to have solder tabs on it. You can't solder to the ends of the batteries without them. You can but the heat that you would need the battery to reach is unsafe for the cell.

 

[Mooper]

https://www.fasttech.com/products/1420/10001980/2741002

3400mah, 4 pack, tabs welded, free shipping.

Free shipping isn't exactly fast, so be prepared to wait a month. But that's the trade off you make.

 

[Brownie]

Thanks man I think i will go with these.
If i order them soon they will come a couple of weeks after i finish my portable. If your sure these are exactly what I need..?
+ How long did you think the charge will last. Its 14.8v 13,600mAh. I'm running the gamecube motherboard, WASP Fusion, 2 x 3v fans, 5v mini amp, memory card (slot a) and a 12v Chinese screen. Rough estimate?

Thanks again

 

[Mooper]

First of all, since you'll be wiring the cells in series, you'll end up with a 14.8v 3400mah pack. Series you add voltage together, parallel you add the capacity.

As for how long it'll last, the GC uses 18-19W, say roughly 3.6W for the screen, and 1.5W per fan, 5W for the audio amp.
About 30W, divided by 14.8V is ~2A

3400mah/2A= 1.7Hours

But keep in mind a fully charged 4 cell battery is 16.8V, so it'll draw less current when full. Also these are just rough numbers I pulled from a few google searches. So the short answer is about 2 hours.

If anyone sees any mistakes in my guesstimate, please do tell.

 

[Brownie]

2 hours is not bad. Thanks for helping me with all this.
I found this on the same website with the batteries you showed me.
Is this what i need? If so i can order them together.

https://www.fasttech.com/products/1...016a15-8a-protective-circuit-board-for-4-cell

 

[Mooper]

Yeah that's the protection circuit you need.