How to properly power a system with Li-Po batteries

[pLover]

Here is how to properly power a portable system with two 3.7v Li-Po batteries in a way that allows the system to charge while in use. Keep in mind, this does not work with systems that require more than 7.4v of power.

Someone correct me if I'm wrong. Especially if I'm wrong about it being able to charge while in use.

 

[pLover]

Where was it before?

 

[Twilight Wolf]

Forum 47. I moved it for you.

 

[pLover]

Oh, thank you.

 

[Twilight Wolf]

No problem.

*Walks casually out of the topic*

 

[QuickSkop3]

Now, back onto topic, That one, or Beta gave me this one (after some long hardships, A lot of F-bombs and some thinking)

http://tinypic.com/view.php?pic=2dhe5ci&s=6

That gonna work?

Granted, I think this is with a wall charger

 

[hailrazer]

Well I don't quite understand.

There has never been a problem figuring out how to charge and play at the same time. You hook up the Pcb and system the exact same way you would normally hook it up.

The problem is that most chargers don't have enough power to charge and play at the same time. So while you are playing and think you are charging you really aren't charging at all until you stop playing the system.

 

[QuickSkop3]

ohh, so you just need a higher value charger than what you have battrywise?

Wait that wont work, If I say, hook up a 11.1V charger to a 7.4V Lion, then that is gonna screw something up, right?

 

[hailrazer]

ohh, so you just need a higher value charger than what you have battrywise?

Wait that wont work, If I say, hook up a 11.1V charger to a 7.4V Lion, then that is gonna screw something up, right?

Not higher voltage, higher amperage.

 

[QuickSkop3]

alright, makes more sense, got any ones that are compatible with a 7.4V li-pos set connected to a PCB?

 

[hailrazer]

alright, makes more sense, got any ones that are compatible with a 7.4V li-pos set connected to a PCB?

Nope and therein lies the problem.

 

[snowpenguin]

My lipo pack uses just a normal regulated wallwart, it's 2.5A and does the job fine.

 

[QuickSkop3]

alright, makes more sense, got any ones that are compatible with a 7.4V li-pos set connected to a PCB?

Nope and therein lies the problem.

which problem is that?

@Snow, can you charge and play at the same time? Also, got a link that will work?

 

[hailrazer]

My lipo pack uses just a normal regulated wallwart, it's 2.5A and does the job fine.

I really don't trust regular wall warts with Li-Pos. All battery sites are quite specific that Lithium Polys need a smart charger.

 

[QuickSkop3]

So, no one has a smart charger for it? that will work.

 

[snowpenguin]

My lipo pack uses just a normal regulated wallwart, it's 2.5A and does the job fine.

I really don't trust regular wall warts with Li-Pos. All battery sites are quite specific that Lithium Polys need a smart charger.

This is a portable DVD player battery, bT-42 I believe. It charges absolutely fine, the charger is not a normal wallwart, it is voltage regulated so it won't change with the different amp draws.

I've not had ANY problems whatsoever, with li ion or lipo cells on the thing.

Also, I think the pcb is not completely normal, I'm pretty sure it has the stuff from smart charges built in and it just needs a constant voltage source with enough amps to power it all.

Hail is correct, QS.

 

[QuickSkop3]

This makes little sense, because the switch has 2 positions, 3 prongs. It can either be in SNES/Battrey position, or it can be in Battry/Charger port position. How does it work if I just insert I higher Charger into it? Il just be running more into an innactive lead.

There are 2 diagrams that I have, which one would I use for this?

OR

I was thinking this might be a good idea.

But the only 2 things im unclear of, is:

1.can I connect 3 together
2. Is there a switch with 4 prongs, 2 positions, and that links 3 leads together?

 

[QuickSkop3]

My lipo pack uses just a normal regulated wallwart, it's 2.5A and does the job fine.

I really don't trust regular wall warts with Li-Pos. All battery sites are quite specific that Lithium Polys need a smart charger.

This is a portable DVD player battery, bT-42 I believe. It charges absolutely fine, the charger is not a normal wallwart, it is voltage regulated so it won't change with the different amp draws.

I've not had ANY problems whatsoever, with li ion or lipo cells on the thing.

Also, I think the pcb is not completely normal, I'm pretty sure it has the stuff from smart charges built in and it just needs a constant voltage source with enough amps to power it all.

Hail is correct, QS.

Wanna link me to the charger, im looking at that BT-42.

Also, you can charge while playing, Read above in my last post please.

 

[snowpenguin]

Your last post is going the hard way that requires two chargers.

Do this, just make sure the amperage of the charger is large enough to power your whole system and charge the batteries at once.

There is no need for a second charger/wallwart.

EDIT:

That was wrong.

LOL. Don't use either of those.

K look.

Attach p+ to your portable and your charge jack. Do the same with p minus. Put a switch on the line to the portable so it isn't always powering the portable if you want to turn it off and charge the batteries.

 

[XCVG]

Wait, if you need a smart charger, what the *Can'tSayThisOnTV* is the point of the protection circuit? It's not like you're going to overdischarge on something as low-draw and voltage sensitive as a portable.

EDIT: Also, you know those cheap camcorder chargers on DX? Pretty sure those are nothing more than power supplies, maybe with a cutoff switch. Far from smart.