FYI; From an email I got today, these odd size wires might be fun to experiment with.
Odd Gauges are back in stock! Nichrome 80, Kanthal A1, Stainless 316L
Odd Gauges are back in stock! Nichrome 80, Kanthal A1, Stainless 316L
Anyone know of a charger (besides large RC types that plug into a lipo pack) that will allow you to set the max charge voltage to 4.1V or so? Mooch has said that charging to less than full voltage will extend the life of batteries and since 'lil 'ol tootle puffer me uses the 20700B batteries which last me way longer than a bottle does I don't need a full charge on them.
Yeah back in the 90's, Palm handheld computers (remember those? I still have a bunch of them) started to use lipos in some of their models (usually color screen models). And I noticed that their lipos lasted about twice as long as other lipos. And when I measured what they were charging their batteries to, it was 4.10v instead of 4.20v. And just before they went out of business again for good, they even went lower and only charged them up to only 4.05v.
And yes like Wayneo stated, the DNA built in charger can do the same and selectable in EScribe. But any charger I've seen that can charge either to 4.10v or 4.20v, will have a selectable setting for either 3.6v or 3.7v cells. Selecting 3.6v charges to 4.10v and 3.7v charges to 4.20v. Years ago they actually had 3.6v lipos. But I rarely ever see any of them anymore.
Another thing you can do is to take it off the charger about at 90% charged. That is usually pretty close to 4.10v. If you drain them down to about the same every time, you can probably figure out how long on the charger it takes to get to 4.10v and set a timer. One word of warning though about taking them off early. Most chargers won't ever get to the balancing step. So you will be taking them off charge probably before it actually gets to this step. So you have to keep an eye on how well the cells are balanced yourself.
Oh yeah, if you can't find a 20700 bay charger with a selectable 3.6v or 3.7v setting (I know they are pretty rare). You could still use a RC charger with a battery holder. You could wire them up so the cells are in series (you would need to add a balance plug too) or in parallel. In parallel it is treated and one large 3.7v single cell to the charger. So it is much easier and you don't have to worry about balancing.
They say hooking them up in parallel, you want all of the cells at the same voltage. Otherwise one will discharge and charge the low one. This is true, but I experimented what if one was at 4.20v and the other was as low as 3.20v. What will happen? I did this test a number of times and I couldn't get any cell to discharge faster or the other charge faster than 1A.
As I didn't like the parallel way of doing this until I did these tests. Now I am not worried about a bit of a difference between cells. And say you accidently did put a 3.2v one in parallel with a 4.2v one. You probably won't even reach 1A and the current will drop off quickly after a few minutes anyway.
They say hooking them up in parallel, you want all of the cells at the same voltage. Otherwise one will discharge and charge the low one. This is true, but I experimented what if one was at 4.20v and the other was as low as 3.20v. What will happen? I did this test a number of times and I couldn't get any cell to discharge faster or the other charge faster than 1A.
As I didn't like the parallel way of doing this until I did these tests. Now I am not worried about a bit of a difference between cells. And say you accidently did put a 3.2v one in parallel with a 4.2v one. You probably won't even reach 1A and the current will drop off quickly after a few minutes anyway.
Watching a cop show, a swat team is getting ready to enter a hotel room where a guy is held up after cutting the hotel manager with a knife, the guy was convicted of murder in the past. Here's the cops stacked up ready to make entry, the female officer takes time to put on either lipstick or chap stick, always be prepared for anything. 
Okay I just spent two hours playing around with the Theme Designer and the pieces are starting to fit together. Not knowledgeable enough to create one from scratch quite yet, but I am getting there. 
Thanks for the instant head and stomach ache Willy. Palm was the 1st of 3 major stock IPO's I bought into that failed dismally. It shot up like a rocket on opening day and never recovered after prices dropped. I think I still have one ..... somewhere.
I'm rebuilding the Mrs. machine into a backup machine. When I tore it down the other day one of the things I coiled up and stuck in the "?" pile was a Palm docking station. I put it right next to the Kodak camera and docking station. The video card is so old it won't even plug into the "new" mobo. Anybody want some technology relics? I'll throw in the Palm Pilot, too.
To be honest, if the case wasn't such a great mid tower, I would've used a gaming mid tower I've got hanging around.
To be honest, if the case wasn't such a great mid tower, I would've used a gaming mid tower I've got hanging around.
I'm not sure about that. Not sure how many amps would flow between a 3.2v & 4.2v battery, it's almost a dead short of 1v delta voltage and current flow would be determined by battery internal resistance along with other factors. This much I can say without doubt, connecting 2 lipos with 1v delta-v instantly burned through a balance connector trace on my lipo paraboard. From that point on I always make sure batts are within 0.2v and connect the main output leads of the lipos to the paraboard first to give the batts a few minutes to equalize before connecting the balance connectors.
On a charging setup with 18650/20700 batts in parallel the same thing applies so the battery sled contacts and parallel hook up wires would have to carry current in excess of probably 5a? Easy enough to test between two batts with an ammeter but I don't have one that's rated for higher than 2a dc.
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Just incase anyone is interested? The Typhoon IV clone came yesterday
It has excellent DTL Air Flow, Good flavour, the JFC, holds nice, no flooding or leaking.
It vapes quite well
How ever the build quality just isn't there
The threading is sharpe,(cut my finger) the build deck screws are insanely tiny! With a tiny alen Key head.
They don't look like they will hold up well at all The glass tube is thin, good thing it's in the SS cage! They include a stupid pair of folding scissors, but no spare glass
IMO not worth the $29, this should have a price of $19.
BTW this is the one I got ShenRay SRG V4 TF GT4 Style RTA Silver 316SS 5ml 25mm Tank Atomizer
These clones are the first round, maybe SXK or SJMY will make a better copy?
It has excellent DTL Air Flow, Good flavour, the JFC, holds nice, no flooding or leaking.
It vapes quite well
How ever the build quality just isn't there
The threading is sharpe,(cut my finger) the build deck screws are insanely tiny! With a tiny alen Key head.
They don't look like they will hold up well at all
The glass tube is thin, good thing it's in the SS cage! They include a stupid pair of folding scissors, but no spare glass IMO not worth the $29, this should have a price of $19.
BTW this is the one I got ShenRay SRG V4 TF GT4 Style RTA Silver 316SS 5ml 25mm Tank Atomizer
These clones are the first round, maybe SXK or SJMY will make a better copy?
Well I first learned this isn't too bad when I read the report of how Samsung 25R are randomly tested. It is probably listed in the data sheet too. If you can't find one online, I think I can find mine to send you a copy. Anyway one of the torture tests they randomly do is to apply 20VDC directly to the battery for 24 hours. I would have guessed it would have lasted about 5 to 20 seconds before she would blow. But it doesn't. Nor did the charge current ever exceed 5 amps in 24 hours. So the battery temperature never reached critical.
Sure you can say this is just one Samsung 25R. How about an Efest, Panasonic, or whatever? Yeah I am sure not all brands of cells and even including some other types of Samsung cells probably couldn't pass that same test. But I did come to appreciate how much tougher the cells we use are compared to what I (perhaps we) would have guessed.
And since I wasn't crazy enough to try to win any Darwin awards by attaching 20V to any of our cells and stand there and watch them for 24 hours. I decided to start with a much safer approach. I don't know if you have any variable CC/CV power supplies around. But they all should have a voltage and a current readout. Interesting enough, they work exactly like our battery chargers do.
With the exception of they lack reverse polarity protection (well some do anyway) and a full charge cutoff. As when the current of charge reaches to 100ma or less, our chargers should disconnect. And variable CC/CV power supplies lack this feature. And you could actually use them for charging our cells if you fully understand this and act accordingly. And I have for 3.3v and 3.0v lithium cells. I even have used them to bring back lithium cells from the dead. There is no guarantee it will work, but I believe feeding it just 10ma will tell you soon enough if it will come back nicely or not.
You can also use a variable CC/CV power supply as a battery replacement too. Better yet, there is zero battery sag if the current is set high enough. And you can test how long a device (mod in this case) will continue to work as the battery voltage drops. And to any outside device connected up to it, it will appear as a cell with zero internal resistance. This is just perfect to do our testing with.
Now take a discharged cell say at 3.20v. Set the power supply at 3.20v and connect them in parallel. What will happen? Absolutely nothing. There will be no current flow or anything. Connected or not connected, it makes no difference at all.
Now we can use the power supply as a simulated cell in parallel. Sure set the max current to whatever you feel comfortable with. Even say 50ma if you are a real chicken. But you could use 1A too for this test. As our batteries can handle charging at 1A. Now slowly start dialing the voltage up. This simulates two batteries in parallel with one that the voltage is climbing.
The more of a difference in voltage, the higher the current. Remember the power supply will never allow the current to exceed our dialed in max current (I used 2.5A for these tests). And you could slowly turn up the voltage to 4.20v (and I have) and I never saw anything over 1A yet. And you could even disconnect one lead and dial in the 4.20v and the other cell is sitting at 3.2v and then connect the leads again. You might get a spike just barely over an amp for less than 100msec, but that is just about it.
So if this is what happens, how does 1A and 2A battery chargers work? Since 4.2v isn't really enough voltage to cause a steady 1A let alone 2A constant charging. As I have at least three pieces of equipment that can create a graph how battery chargers pulls this off. And fast battery chargers are exceeding 4.2v per cell, I am sure of it and you can see this when you measure them. Of course they monitor what the battery voltage charge is up to, so they won't ever allow the battery voltage to exceed 4.20v per cell.
Mine, same one, is a few days from delivery. FT has this one now: $17.53 SRG V4 Styled RTA Rebuildable Tank Atomizer - 5ml / stainless steel + PC / 25mm dia. at FastTech - Worldwide Free ShippingJust incase anyone is interested? The Typhoon IV clone came yesterday
It has excellent DTL Air Flow, Good flavour, the JFC, holds nice, no flooding or leaking.
It vapes quite well
How ever the build quality just isn't there
The threading is sharpe,(cut my finger) the build deck screws are insanely tiny! With a tiny alen Key head.
They don't look like they will hold up well at all
IMO not worth the $29, this should have a price of $19.
BTW this is the one I got ShenRay SRG V4 TF GT4 Style RTA Silver 316SS 5ml 25mm Tank Atomizer
These clones are the first round, maybe SXK or SJMY will make a better copy?
Glass is really thin on authentic with small set screw hex as well...just saying.
I don't think they ever put more than 4.2V on a cell to charge it faster, more current is applied to the constant current phase of the charge cycle.
Fast-Charging Trends and Challenges for Single-cell Batteries
Yeah I dunno I couldn't explain what happened in your case. And I haven't read this anywhere, but it has to be our batteries have a totally different internal resistance between discharging and changing. As our cells have no problems supplying high current when discharging. But they are really resistive when charging. That would explain why discharging C rating is quite different than C rating for charging. Here let me check if I could find anything.
Oh boy did I get that 20v test all wrong. Here it is.
9.1 Safety
9.1 Overcharge test
Test method: To charge with 20A-20V at 25°C for 2hr.
Criteria: No fire, and no explosion.
So it wasn't 5A, but 20A. And not 24hr, but 2hr. Sorry, but that is still very good if you ask me.
Here is a chart between charging internal resistance vs. discharging resistance.
Figure 7. Internal Resistance Change Curve in Charging-discharging...
It came from "On-line Measurement of Internal Resistance of Lithium Ion Battery for EV and Its Application Research" publication. And it shows there can be, but either case it isn't a lot of a difference. And Samsung data sheet says:
7.0 Characteristics
7.5 Inital internal impedance
Initial internal impedance measured at AC 1kHz after standard charge
Initial internal impedance < 18mΩ
So Samsung is taking the average between the two at 1kHz. I dunno, I need to study this more.
You can see the higher voltage on my two 15 year old Triton RC chargers. I can dial in up to 2.5A for 3.7v lithium cells. 5A for other types of cells. And no CC phase is ever going to get 1A @ 4.2v. Not if the cell is 3.2v or higher. I could even set my two CC/CV power supplies at 2A @ 4.20v to a 18650. And it won't deliver 2A either. I have to raise the power supply to way over 4.20v before the cell will take 2A.
I just did a simple DVM test on my XTAR SV2 Rocket.
I had a low VTC6 and figured it would be a good battery to check as they have a crazy Fast Charge rating of 5A. Mooch rates them at 1.5A for Max Life rate and 3A for Standard rate.
Started on the 0.5A range popped the battery in and let it settle in a few minutes. The LCD read 37% and I measured 3.7V on the charge posts. Switching the charge rate switch to 1A and 2A. I continued to measure 3.7V on the posts.
Putting the meter in series with the battery I measured 0.48A, 0.97A and 1.9A switching between the 0.5A/1A/2A settings.
I thought it might be that your 25R might not take anything over a 1A charge rate, but Mooch's chart shows that is not the case.
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