PTR08100W Mod Box
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looks good!
How did you accomplish in-the-mod charging? I am assuming you are using 2 li-ion batteries in series, which means they would have to be changed to parallel for charging.
How did you accomplish in-the-mod charging? I am assuming you are using 2 li-ion batteries in series, which means they would have to be changed to parallel for charging.
Yes it has two batteries in series i took a board out of a 7.2V transformer hooked it up to a 9V transformer (see pic above)that got me down to 10.98V added two diodes and got 10.34V tested it under load and got 7.9V wow! so i knew i could charge in series. I made the charger first so i knew i could charge the mod. The batteries are 3.7V 650mah with protected circuit, i added a switch to cut power to the regulator so there is no feed back when in charge mode with an LED so i know its on charge mode. The 9V transformer put out 14V i tryed three of them all the same but the 7.2 transformer put out only 7.2V i don't know why. And i wanted to add a bicolor LED in the charger box so i know when its charging and when its done charging but i don't know how to hook it up.
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does the charger automatically stop charging in overvoltage/overcurrant situations? or are you relying on the protection circuits of the batteries? Also, from what you describe, you are charging the batteries in series, correct?
I am relying on the protection circuit of the batteries from over load charging and yes charging in series. Good thing is used cell phone batteries at the goodwill for 1 dollar thats why i am using them.
Li-Ion Charging Information
you, sir, are playing with fire, literally. Protection circuits do not always work, and if one should fail while not being monitored, you could have a fire/explosion on your hands.
Most chargers are current limited and voltage limited. They signal that the batteries are fully charged after current drops to a preset number, and the voltage is around 4.2. It does not seem like there is any sort of official protection at all in your setup, other than the battery protection.
It might be a good idea to redesign your charging setup before continuing to charge they way you currently are. As it stands, your setup is a big safety issue. Just because it works, doesn't mean it works right. It only takes one mishap to completely change everything.
you, sir, are playing with fire, literally. Protection circuits do not always work, and if one should fail while not being monitored, you could have a fire/explosion on your hands.
Most chargers are current limited and voltage limited. They signal that the batteries are fully charged after current drops to a preset number, and the voltage is around 4.2. It does not seem like there is any sort of official protection at all in your setup, other than the battery protection.
It might be a good idea to redesign your charging setup before continuing to charge they way you currently are. As it stands, your setup is a big safety issue. Just because it works, doesn't mean it works right. It only takes one mishap to completely change everything.
Not all cell phone batteries have a protection circuit in them.
Since you quote voltage measurements, I assume you have a meter.
Strange how some modders don't.
I also recommend you evaluate your circuit to be sure that charging is balanced and that there is minimal possibility of ending up with one fully charged, and one NOT fully charged. It's fun to mod. It's not fun if someone attemps to copy your work and has a problem from either bad design, or incomplete information about how you accomplished what you did.
As a modder at home your responsibility is limited to those around you. That responsibility expands when you post your mod on the internet (there are dummies out here
).
Recheck your concept, and have safe fun.
Rocket
Since you quote voltage measurements, I assume you have a meter.
Strange how some modders don't.
I also recommend you evaluate your circuit to be sure that charging is balanced and that there is minimal possibility of ending up with one fully charged, and one NOT fully charged. It's fun to mod. It's not fun if someone attemps to copy your work and has a problem from either bad design, or incomplete information about how you accomplished what you did.
As a modder at home your responsibility is limited to those around you. That responsibility expands when you post your mod on the internet (there are dummies out here
). Recheck your concept, and have safe fun.
Rocket
Ok so you say my charge is no good, I did test it when charging the batteries in series with a volt meter on it and it did stop charging so i know the circuit protection is working. But like you said i can't relying on only that to be safe. I want it to be safe and you know a lot more about this then i do, is there any charger that you know of that i can mod to charge in series? I was looking at one from battery junction.com Dual LI-Ion button cells 3.6v might be able to make this one work.
Dangers of Li-Ion cells
check out these:
2200 mah 7.4v LiPo battery pack
Balancing LiPo/NiMH charger
keep in mind, though, that the most safe way to charge li-ion cells is either 1 at a time, or in parallel. The more you stack, the more unsafe it becomes.
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Thank for all the info o4_srt I did't know that when the li-lon batteries get unbalanced they can dead short and explode/burn. And to buy a good balancing/charger rewire my mod, Its not worth it, I am just going to get two 14500 batteries and a charger. Take out the batteries and charge them, that seems to be the best way to bulid a mod. So i am out 4 bucks and some time but i did learn a lot and i didn't burn down the house.
good idea
and like I said before, you could always use 1 battery and a boost converter to raise voltage. Since you would only have 1 battery, you could charge in the mod, as long as the battery was able to be isolated from the rest of the circuit.
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