charge and play?

[I am Noah]

Hai!
For my n64p I wanted to make it be able to play off of the batteries, and also play off wall power (charge and play). But I have no idea how to. Can someone post some sort of guide please? And I heard that you need a dpdt switch to do this, and I brought these 2 from radio shack.http://comingsoon.radioshack.com/search?q=dpdt+rocker
would these work?
Thanks!

 

[asdfqwer426]

as far as i know, the main issue is that there isn't a charger that has the right amperage to charge the batteries and run the system at the same time. if the charger amperage is high enough to run the console, then the batteries will likely get fried. if the amerage is low enough to charge the batteries correctly, then when the system is running, it draws more power than the charger can supply, so it slowly drains the batteries because the charger can't keep up.

to get around this problem, some people install 2 charge ports, one that runs the system, and one that charger the batteries. with this set up, any spst switch could be used.

another option, one i'm guessing you read about, would involve a dpdt switch and a single charge port. it would still need 2 chargers, but it would likely save space in the build. throw the switch one way, it charges the batteries with one charger, throw it the other way it has the power to run the system with the other charger.

i'm just guessing this is whats up. how this is all set up depends on your build. finding 2 chargers the right voltage and size, with 2 different amperages. i could probably draw up wiring if you needed it, let me know.

 

[C4RB0]

Yes, the DPDT switches work if you wire them up like this:
viewtopic.php?f=36&t=14089

Note that for the N64 you don't need the 5V and 1.7V regulator. As asdfqwer426 wrote, you'll need a smart charger to charge li-ion batteries or they will blow up. Since these chargers are not designed to power the system, you'll also need a 7.5V (or 12V) power supply. It's also recommended to use two different charger/power ports such that you can't plug the power supply in the charger port accidentally.

 

[I am Noah]

For the project, I'm using 2 lipo batteries

 

[I am Noah]

Can someone post some sort of diagram? Thank all of you!

 

[Miceeno]

as far as i know, the main issue is that there isn't a charger that has the right amperage to charge the batteries and run the system at the same time. if the charger amperage is high enough to run the console, then the batteries will likely get fried. if the amerage is low enough to charge the batteries correctly, then when the system is running, it draws more power than the charger can supply, so it slowly drains the batteries because the charger can't keep up.

to get around this problem, some people install 2 charge ports, one that runs the system, and one that charger the batteries. with this set up, any spst switch could be used.

another option, one i'm guessing you read about, would involve a dpdt switch and a single charge port. it would still need 2 chargers, but it would likely save space in the build. throw the switch one way, it charges the batteries with one charger, throw it the other way it has the power to run the system with the other charger.

i'm just guessing this is whats up. how this is all set up depends on your build. finding 2 chargers the right voltage and size, with 2 different amperages. i could probably draw up wiring if you needed it, let me know.

I used an internal smart charging pcb in my Nintendo Sixty 4or the Win. I only have a single DC in port and it works quite well. The smart charger can handle the extra load but it takes longer to charge (as does any battery powered device when you use them while charging). The only catch is that it requires a power supply that puts out 5 amps at 12 volts. Whereas you only need 1.5-2 amps to either run the system or charge the batteries.

I wired it so the portable is always connected to the batteries, the batteries connected to the charger, and the charger connected to the DC in port. 99% of all portable electronics and laptops are configured like this.

If you wanted to speed up charging you could do everything listed above except connect the portable to the DC in as well as the batteries and put a diode between the batteries and the portable. This would allow the smart charger to safely charge the batteries while the portable draws from the DC in instead of the batteries (electricity will follow the path of least resistance). I didn't do it this way because while it sounds good in theory and on paper I don't know how it will work in practice. You may pop diodes or overcharge the batteries cause an explosive fireball to appear in your hands while playing.

EDIT: Whenever I say connect to batteries I mean to the batteries load balanceing / low voltage drop out / protection PCB (which is then connected to the batteries) . You shouldn't connect directly to the batteries if you can help it.

 

[C4RB0]

I used an internal smart charging pcb in my Nintendo Sixty 4or the Win. I only have a single DC in port and it works quite well. The smart charger can handle the extra load but it takes longer to charge (as does any battery powered device when you use them while charging). The only catch is that it requires a power supply that puts out 5 amps at 12 volts. Whereas you only need 1.5-2 amps to either run the system or charge the batteries.

Is that safe? (I'm genuinely asking.) Even if it seems to work, this doesn't mean that the battery is charged safely. A smart charger is a constant current constant voltage charger. If the battery is almost fully charged it charges with 4.2V and decreases the supplied current (see the figure in this stackexchange post: http://electronics.stackexchange.com/qu ... attery-cha). Wouldn't the portable suddenly turn off when the allowed current isn't high enough anymore?

99% of all portable electronics and laptops are configured like this.

I don't think this is true. They may have only one charging port but they have additional circuitry that properly manages charging and discharging at the same time (similar to this http://www.batteryspace.com/CMB-for-11. ... -char.aspx).

 

[I am Noah]

For the project I'm using 2 lipos. A diagram would be greatly appreciated.
thank you!

 

[Miceeno]

I used an internal smart charging pcb in my Nintendo Sixty 4or the Win. I only have a single DC in port and it works quite well. The smart charger can handle the extra load but it takes longer to charge (as does any battery powered device when you use them while charging). The only catch is that it requires a power supply that puts out 5 amps at 12 volts. Whereas you only need 1.5-2 amps to either run the system or charge the batteries.

Is that safe? (I'm genuinely asking.) Even if it seems to work, this doesn't mean that the battery is charged safely. A smart charger is a constant current constant voltage charger. If the battery is almost fully charged it charges with 4.2V and decreases the supplied current (see the figure in this stackexchange post: http://electronics.stackexchange.com/qu ... attery-cha). Wouldn't the portable suddenly turn off when the allowed current isn't high enough anymore?

99% of all portable electronics and laptops are configured like this.

I don't think this is true. They may have only one charging port but they have additional circuitry that properly manages charging and discharging at the same time (similar to this http://www.batteryspace.com/CMB-for-11. ... -char.aspx).

This is what I have in the portable http://www.batteryspace.com/Interna....2A-for-7.4V-Li-ion-Rechargeable-Battery.aspx. It is a smart charger, it is safe, and it is equivalent (not 100% the same of course) to the additional circuitry in 99% portable electronics. The portable doesn't shut off when the battery is almost fully charged (when the smart charger lowers voltage) because it's drawing from the batteries (that are at the almost fully charged voltage, in this case 7.4 volts maybe a little more), the batteries just get warmer and take longer to charge. This smart charger also has a thermal probe that will cut charging if the batteries get too hot. The danger is when the batteries are too warm to charge (when the smart charger stops charging due to heat) and you continue to run the portable creating more heat. Smart phones will detect the dangerous temperatures in the batteries and shut down. In the portable there isn't any thermal shut down protection unless you get creative with a micro-controller.

To make this system "safer", you can get creative with diodes or relays and tweaked wiring.

 

[Miceeno]

C4RB0, just in case you come back and tell me that the board you listed and the board I listed aren't the same. The way to make the board I listed function almost identically all you need is the battery protection pcb (which comes on almost all battery packs) and an led fuel gauge. The battery protection pcb that I used looks and acts like this one. And it came wrapped in the plastic on the Tenergy 7.4V 2200mAh Battery Pack. As for the led fuel gauge I used something similar to this one.

While the board you listed is a little smarter, my solution works just the same and it was the best I could find at the time. I'm working on a slightly different version in my upcoming portables.

 

[C4RB0]

I don't really question that the smart charger you're using is safe. I just wonder if the way you wired everything up is safe when you play and charge at the same time. That the battery gets warmer doesn't seem to be a good sign. Since batteryspace.com doesn't show any schematics of their design and I don't have the necessary knowledge, I can't refute your claims but I still remain sceptical.

 

[Miceeno]

Use any portable electronic that can be used while charging and you will notice it (the battery) gets warmer and charges slower than when you charge it without using it. My laptop, smart phone, 3ds, etc all behave this way. Test this with your own professionally engineered devices. Also, every rechargeable battery gets warm when you charge it. And when I say gets warmer when you play and charge simultaneously I mean by less than 5 or 10 degrees (just enough that it is noticable). This shouldn't be alarming because all batteries generate heat when they discharge. So you are getting heat from charging, heat from discharging, and heat from inefficiencies. The only time when the heat should be alarming is when it exceeds the maximum safe heat for the chemistry of the battery.

 

[I am Noah]

Hey! I was wondering if anyone can post/link me a diagram for this. Thank you!