Internal usb charging; best/safest method?

[Digital-Dragon]

I was looking at that one also, seems good...

I have been wondering about dealextreme, I'll avoid them like I do all chinese vendors.

I have a few 2000mah protected trustfires, and a few 2000mah aw imrs, all 18650s. I gave the vv mod I built to a friend who loves vv, but I'm fine with unregulated atm, and having the extra half volt or so that the imr puts out under load really seems to make a difference, plus the imrs seem to last a lot longer... (not that I ever actually run them dry,) and I like the "safer chemistry" thing, and it seems to me that safer chemistry, combined with protections, would be, well, even "safer."

I finally understand the current rating thing, at least more than I used to... Java_az helped me out a bit. He said I should look for a protection pcb with a cutoff around 4A to 6A, becuase a 1.5 ohm atty on an unregulated mod will be using just under 3 amps according to him. I love my 1.8ohm bridgless 306s, so I assume they are using slightly less amps than that.
If 4A is really the lowest I should go that annoys me, because this seems really close to being perfect for my needs: Battery holder : Li-Ion 18650 Battery Holder (1S1P) With 2.6" long 20AWG & PCB (1S1P-18650)
And they also have this battery which looks okay, but they don't say if it's an imr, or a regular unprotected li-ion... LG Lithium 18650 Cylindrical Rechargeable Cell: 3.7V 2600mAh (9.62Wh))

This is all coming together, I'm exited!

 

[CraigHB]

This is all coming together, I'm exited!

Sounds like you're getting it all sorted out. Good to hear things are coming together for you. Have fun!

 

[Digital-Dragon]

Sounds like you're getting it all sorted out. Good to hear things are coming together for you. Have fun!

Oh yeah, learning about and building this stuff is super fun! Thanks CraigHB! I feel much more competent now than when I first started this thread not that long ago. And you played a big part in my "electronics education" lol, even if you didn't know you were... I googled "protection pcb aw imr" and even though I had never really checked out the breaktru forum, it was the first result, and a post you made in that thread was helpful.

I'm about to order the last few things I need to get this done, and I'm just going to try a few different batteries and chargers and protection pcbs in a few different mods, and see which ones seem to the best. Guess I'll know which ones aren't the best if anything explodes lol... But, as you stated, I probably should stop using these imrs in my unregulated mods...

I'm still very open to advice from anybody who is also interested in this stuff, and I still have some unanswered questions throughout this thread. I know I still have a lot to learn, and I really don't wanna burn my house down...

 

[Rader2146]

And they also have this battery which looks okay, but they don't say if it's an imr, or a regular unprotected li-ion... LG Lithium 18650 Cylindrical Rechargeable Cell: 3.7V 2600mAh (9.62Wh))

That is an unprotected ICR cell.

http://www.batteryspace.com/prod-specs/5457_1.pdf

 

[breaktru]

I built this for my micro-controller mod. Runs two Series Li-Po 20c batteries for vaping and charges them in parallel w/ a USB charger shown below. The USB charger is rated at 500mA and the wall adapter is a 1000mah (1A).
The circuit will place the Li-Po's in series (8.4v) when the 3.P.D.T. switch is in the UP position and the Li-Po's will be in parallel with the 3.P.D.T. switch is in the DOWN position which also places the USB charger on line.

So far I charged the half charged batteries until the Red LED extinguished (about 2 hrs) and each battery measured 4.19v at charge completion.

The circuit has been revised using Craig's expert suggestions. As per his suggestions I added an additional Fuse (F2), removed a Zener Diode I had and replaced the DPDT with a 3PDT switch. Thanks Craig.

 

[Digital-Dragon]

Oh wow, breaktrue... I'm honored to be in your presence, thanks for sharing that!

Have you had any issues with the durability of that micro usb charger, as far as it only having 2 solder points? I ask because the comments about it made it seem like it will break easily.. And the mini usb version of that charger has 4 solder points, and got more favorable comments...

Also, would aw imrs work instead of li-pos in your above design?

 

[breaktru]

Just got it together a couple of days ago and the mod it's in is not completed. Waiting on a decent case to house it in.
I bought the Micro version several months ago only because the Mini was sold out. Thanks D-D for pointing out the weak point. I'll make sure when I install it in a case that I secure it firmly so not to move.

IMR's should work as well, unless one of the experts see a problem with that. Let's hear from one....

 

[slimest]

I am not shure that simple switching batteries from series to parallel to charge them is a good idea. Every battery has its own discharge performance, so when you connect them in parallel, one of them can have a higher voltage and charges another without current limit. There is a good practice: if you connect a batteries in parallel, first balance them through a resistor. This way is safer.

 

[StrikeEagleCC]

I am not shure that simple switching batteries from series to parallel to charge them is a good idea. Every battery has its own discharge performance, so when you connect them in parallel, one of them can have a higher voltage and charges another without current limit. There is a good practice: if you connect a batteries in parallel, first balance them through a resistor. This way is safer.

I've been wondering about that myself. There exist some fairly in-depth cell balancers for hobby lipo packs, but wouldn't connecting them in parallel with an appropriate resistor do just as well? What am I missing?

 

[digunderground]

@ digital-dragon / OP

This might work and be close to the diameter of an 18650. It looks like you could wire it to work at the top of a tube mod to regulate overcharge / over discharge for any unprotected battery you use.

Charge/Discharge Circuit Board for Rechargeable Li-Ion Batteries, protective | eBay

I've been looking at this for modding and im not sure if in conjunction with the 5v usb charger board it would work but it looks really promising. If I understand the specs correctly, this is basically a protection circuit, similar to whats on a protected battery but this is separate and may offer more features / flexibility.

hopefully someone else chimes in and either agrees or disagrees. I'm fairly experienced making electronic things but by no means an expert when it comes to Lithium ion stuffs.

 

[slimest]

StrikeEagleCC, I am talking about different thing. About fast switching from "in series" to "in parallel". If you use a balancing charger, you don't need a such switching.

 

[Digital-Dragon]

@ digital-dragon / OP

This might work and be close to the diameter of an 18650. It looks like you could wire it to work at the top of a tube mod to regulate overcharge / over discharge for any unprotected battery you use.

Charge/Discharge Circuit Board for Rechargeable Li-Ion Batteries, protective | eBay

I've been looking at this for modding and im not sure if in conjunction with the 5v usb charger board it would work but it looks really promising. If I understand the specs correctly, this is basically a protection circuit, similar to whats on a protected battery but this is separate and may offer more features / flexibility.

hopefully someone else chimes in and either agrees or disagrees. I'm fairly experienced making electronic things but by no means an expert when it comes to Lithium ion stuffs.

I've seen the one you linked to before, and I don't think it is ideal for a few reasons... Firstly, it has a 10A cutoff, and from what I understand, 4-6 is better for our purposes as 10 would be kinda pointless... Second, it doesn't list any of the other protections actuall numbers, just says it has them...

This one was recommended by Craig - Protection Circuit Module (PCB) for 3.7V Li-Ion Battery (6.0A limit)
its bigger, but seems much more suited to our needs.

 

[Java_Az]

I've seen the one you linked to before, and I don't think it is ideal for a few reasons... Firstly, it has a 10A cutoff, and from what I understand, 4-6 is better for our purposes as 10 would be kinda pointless... Second, it doesn't list any of the other protections actuall numbers, just says it has them...

This one was recommended by Craig - Protection Circuit Module (PCB) for 3.7V Li-Ion Battery (6.0A limit)
its bigger, but seems much more suited to our needs.

I got my order of protection chips the other day. Slapped one in the test circuit for the mod i am building and they wont work with the high drain Panasonic's. The CGR18650CH's have 3 times lower impedance then the regular Li ions. my best guess as to why they wont work. slapped a regular li Ion in the circuit and the protection chip worked fine. Live and Learn i guess. Not sure if all protection circuits are going to do this but my guess is they will. Anyway thought i would throw that info out i know someone asked if IMR's would work with protection PCB's.

 

[Digital-Dragon]

I got my order of protection chips the other day. Slapped one in the test circuit for the mod i am building and they wont work with the high drain Panasonic's. The CGR18650CH's have 3 times lower impedance then the regular Li ions. my best guess as to why they wont work. slapped a regular li Ion in the circuit and the protection chip worked fine. Live and Learn i guess. Not sure if all protection circuits are going to do this but my guess is they will. Anyway thought i would throw that info out i know someone asked if IMR's would work with protection PCB's.

Oh wow, horrible news... I was about to order a few of those panasonics... Do you think it was just those, or would the aw imrs also not work with protection pcbs?

PS, there is a lot of info about those panasonics here: http://www.e-cigarette-forum.com/fo...e-made-2250mah-10a-imr-battery-aw-slayer.html

Edit: what are the specs of the protection chips you are using Java?

 

[Rocketman]

That's odd. I've used protection boards with 26650 IMR cells.
both the 6 amp one from BatterySpace and the 4 amp ones from DX.

 

[Java_Az]

Oh wow, horrible news... I was about to order a few of those panasonics... Do you think it was just those, or would the aw imrs also not work with protection pcbs?

PS, there is a lot of info about those panasonics here: http://www.e-cigarette-forum.com/fo...e-made-2250mah-10a-imr-battery-aw-slayer.html

I just tested with some older lower amp PCB's i have laying around same thing. No Joy. My best guess would be that AW IMR's will not work also. That is if my theory is correct and it has to do with the low impedance of these high drain batteries. I dont have any AW IMR'S so i cant test them. The PCB's i just got are tenergy branded and the old ones i have i got off the slow boat from china ( so no brand ). I have one more kind of PCB that i will have to wire to a 2 cell holder since it is for 7.4 volts. I will slap it together really quick and see what it does.

 

[Rocketman]

did you activate the protection board? I don't think the protection circuit can tell anything about cell resistance at very low currents.

 

[Java_Az]

did you activate the protection board? I don't think the protection circuit can tell anything about cell resistance at very low currents.

Loaded or unloaded they wont work with the CGR18650CH pano's. The Protection PCB's turn them self's on as long as the voltage is in range you get a output voltage reading, not sure what you mean by activating them. They work fine with a Li Ion lots of vapor. Slap a CGR18650CH in the battery holder and no joy.

I have the 7.4 protection PCB soldered up and ready to go. I just have to wait for one of the CGR18650CH's to charge . Putting them in series with different voltages would not be good. So it will be about 2 1/2 hours before i can test it.

 

[Digital-Dragon]

Okay Java, as you know I'm still learning about all this stuff, but I do have a theory about what's going on. In that "aw slayer" thread I linked to in my last post, there is mention of the Panasonics not being recommended for regulated mods, though they do work great in many vv mods, their spec page was quoted as sayings they should only be used in unregulated mods... Maybe some protection pcbs are overwhelmed by them?

I just find it hard to fathom that imrs won't work with any protection pcb, when many folks have recommended that set-up to me...

I'll still get a couple of those Panasonics as they seem at least as good as the aws, and even safer...

 

[Java_Az]

did you activate the protection board? I don't think the protection circuit can tell anything about cell resistance at very low currents.

I see what your saying now, this third chip wont activate until a load is applied as where the other ones just needed voltage and they turned on. I think it will turn out that not all protection PCB's will work with the Pano's and or IMR's . Got a feeling this PCB will work when the battery gets charged. Got some regular li ions in it now. Another hour or so i will report back.