Camera battery mod?

[SeanO'Connell]

Ok I know everyone has seen the batteries that some higher end cameras use. U know the flat rectangular ones. Well I was looking at some while at bestbuy the other day and I came across a couple that were no more then 4mm thick 1 inch wide and 2 inches long. They ranged from 3.6-4.8v ,500-1500mah and 1.5-3amps. Leading me to believe that if I could use these for slimmer sleeker box mods instead if the traditional cylindrical cells. Has anyone tried using these types of batteries yet? Or am I somehow the first one to think of it?

 

[MastiffMike]

I had looked into them a couple years ago. Problem was the size-mah-price didn't make them very appealing. The most intriging I found were actually batteries for medical devices, but then $30-$50 for a battery didn't seem worth pursuing. Not sure if things have changed since then though. If I was looking for a rectangular battery today, I start by looking at batteries for charging portable devices (cell phones,mp3 players, gaming systems) but I've no idea if the size-price-performance is there.
If you find something, I'm sure a lot of people will want to hear about it!

 

[mightypirate]

I know most cell phone batteries are 3.7v. I believe my Thunderbolt battery is 1400mah and the extended ones are 2700mah (I believe). Theyre pretty wide though, 2 inches or so. So while they may make your mod thinner its still gonna be wide. Amazon has the incredible batteries for $8 with free shipping for prime members if anyone is interested.

 

[SeanO'Connell]

Mastiff mike, well I'm working on a NES controller mod so width isn't really going to be a problem,

Mighty pirate, well im interested that's for sure do you know what kind of amperage it puts out ... Because some cell phone batts I've seen only out out like .25-.5 amps wich isn't enough to fire a atty.

 

[SeanO'Connell]

Also mastiff mike ... The one I was looking at was no bigger then you're palm, had 1500 mah and was $14.99 if I remember correctly

 

[mightypirate]

Well here's the thunderbolt battery info:

Model:BTR6400B
3.7vdc. 1400mAH
5.18Whr

And on the inside of the phone itself


5vdc === 1A

 

[CraigHB]

Cell phone batts and other flat cells like PSP batts are sketchy. They typically don't make the specs available for them other than the mAh rating and assuming a 1C max discharge rate is not a safe assumption. The are not necessarily protected and like any unprotected Li-Ion, they can blow up in your face if pushed beyond their limits.

You can get the hobby flat cells really cheap. They're not as compact becuase they have high drain rates, starting at 20C. Like an IMR round cell, the charge density by volume is is lower, but the hobby cells are least expensive. At the very minimum, you need to add a fuse to use them safely. Same can be said for any unprotected Li-Ion.

 

[SeanO'Connell]

Well I was thinking about using a flat cell for an NES controller mod I'm making . And I definitely have more than enough room for a fuse.

 

[srolesen]

generally camera batteries for high end camera's have good amp draw capabilities, because camera's draw much higher amps than other battery electronic like phone, psp etc.
battery from bestbuy might not be up to scrap compaired to original battery tho, i dont know.

i'm trying this one for RC people instead:
HobbyKing R/C Hobby Store : Turnigy nano-tech 850mah 2S 25~40C Lipo Pack

 

[CraigHB]

You don't need the higher C rate for an e-cig mod. This one would do the job and it's cheaper with a little more capacity.

 

[srolesen]

You don't need the higher C rate for an e-cig mod. This one would do the job and it's cheaper with a little more capacity.

yeah guess so, but figured i'd want to try fast charging at 5C, but having trouble finding IC for it :/

 

[CraigHB]

No, you won't find something you can build-in to your mod that will charge that battery quickly. Most of the modules out there are limited to 500mA and some are as high as 1A or 1.2A. That's one of the reasons the hobby guys use those expensive chargers, they have a wide adjustable charging rate. However, the faster you charge a Li-Ion, the faster it wears out. Even the hobbyists usually try to stick to 1C.

Also, if you're talking about built-in charging with that battery, it's a whole other can of worms. You wan't to use a balancing charger the extra battery connector is designed for. You can find cheap ones like this.

 

[srolesen]

No, you won't find something you can build-in to your mod that will charge that battery quickly. Most of the modules out there are limited to 500mA and some are as high as 1A or 1.2A

for referance highest amp IC i see for charging is from adafruit
https://www.adafruit.com/products/280

i dont know about the C rating when charging, and how it affects battery durability, but i guess that as battery has large discharge rating and low internal resistance, and it does not get warm when charging then fast charging is less of a concern for durability, but that is me guessing. allso battery is cheap.
it's strange that there are good number of 2 amp chips for charging, but only for people with mad soldering skillz :/

Also, if you're talking about built-in charging with that battery, it's a whole other can of worms. You wan't to use a balancing charger the extra battery connector is designed for. You can find cheap ones like this.

thanks, i kinda hoped to wire batteries in parallel instead of series so i would have simpler charging, is this bad idea ?

 

[CraigHB]

It's perfectly fine to parallel Li-Ion batteries with one caveat. You want to make them non-removable. In other words, they should be permanantly attached in a pack. The reason is, like you said, the internal resistance is very low and high equalization currents can occur if the charge differs by much at all when initially connected. People do run removable batts in parallel, but you need to exercise care to avoid installing cells with a charge imbalance. There's also the risk of reverse installation which is even worse. A protected cell will keep anything ugly from happening whatever the case, but it's risky when using unprotected cells.

The hobby batteries (like the one you linked to) are always in series. I suppose you could take the pack apart and rewire it, but you don't need to do that. You can buy the cells individually. Hobbyking has individual cells by far the cheapest, but with a minimum 20C. You can find them anywhere from 2C to 20C through online shops like batteryspace.com, but they're a lot more expensive.

Single (or parallel) cells are much easier when it comes to built-in charging. I'm not going to get into what it would take with a series mod, it's just not worth the trouble. For series cells, just use a dedicated charger connecter. For a single cell, it's easy to install a USB charging module, but keep in mind, it's best to use a charging port like a wall adapter or powered USB hub. Even then, you need to make sure it can handle the current demand. Most computer USB ports have current limitations well below the the 1A or 1.2A rate a module may be able to supply. If you want to use a charging rate higher than that, what I said before still stands. You'll need a higher end charger with a dedicated connector. That's regardless of cell configuration.

One word of caution about high charge rates; the risk of a Li-Ion cell venting (going up in flames) increases exponentially with charge rate. The hobby guys charge their cells in a fireproof container even when using a 1C rate. If you actually do set up a charge rate at 5C, then you absolutley must charge your mod in a fireproof container.

 

[srolesen]

Single (or parallel) cells are much easier when it comes to built-in charging. I'm not going to get into what it would take with a series mod, it's just not worth the trouble

so what is the best solution:

1. go with permantly parallel cells and use boost circuit for better vaping
2. make circuit for charging cells in parallel, but couple cells in series for use with buck circuit

seemed to me that boost would be best because it makes it less complex (and more safe) to charge mod, but most people here seem to go with buck strategy ???

One word of caution about high charge rates; the risk of a Li-Ion cell venting (going up in flames) increases exponentially with charge rate. The hobby guys charge their cells in a fireproof container even when using a 1C rate. If you actually do set up a charge rate at 5C, then you absolutley must charge your mod in a fireproof container.

yeah i know it seems dangerous to charge cells at high C rates, but i had camera battery vent on me at less than 1/2C (idk if it was original one, but i suspect not)
so if batteries can vent even at low C rates then it might be better to charge at high C rates and pay a bit of attention for those 15 minutes instead of letting it charge while you sleep or your out.
afaik nanotech lipoly have very low internal resistance compaired to normal lipoly so they should not get warm even with high C charging

 

[CraigHB]

I've been using the 20C 2200mAh standard cells from the same maker and have charged them at 2C before (that's 4.4A). They don't warm up at all. Internal resistance is about 7mΩ per cell as measured on the bench. That's ultra-low. An IMR 18650 is around 25mΩ. So, I dont' think you need higher end cells just for lower internal resistance. They probably are not much lower than the standard cells. They do have the higher charge rate. 2C is pretty typical for hobby LiPos. 5C is way up there.

Single cell booster or dual cell buck is always the big question. Each has the their pluses and minuses. Single cell booster makes USB charging easy. It's more convenient and more compact when using removable cells. Dual cell buck gives you much higher output capability and wider voltage range. Dual cell buck also allows you to use lower drain protected round cells. Boost requires high drain cells.

You're right about charging. It would be safer to charge a cell at its maximum rate in the proper environment than to charge one at a minimal rate on the floor unattended.

It's actually uncommon to hear first hand about someone experiencing a Li-Ion battery failure. What happended with your camera? I have a friend who experienced a Li-Ion failure on one of her e-cigs. It took off like a rocket from the charger spraying super hot electrolyte. Fortunately she was home when it happend and was able to deal with it. Might have burned down her house otherwise. All of the accounts I have heard first hand have been during charging.

 

[srolesen]

I've been using the 20C 2200mAh standard cells from the same maker and have charged them at 2C before (that's 4.4A). They don't warm up at all. Internal resistance is about 7mΩ per cell as measured on the bench. That's ultra-low. An IMR 18650 is around 25mΩ. So, I dont' think you need higher end cells just for lower internal resistance. They probably are not much lower than the standard cells. They do have the higher charge rate. 2C is pretty typical for hobby LiPos. 5C is way up there.

is it resonable to think that failure happens as a factor of thermal stress+chemical wear, rather than as a factor of charge rate, so that if thermel stress is lowered with lower internal resistance nanotech then higher C charging does not increase failure risk noticably ?

Single cell booster or dual cell buck is always the big question. Each has the their pluses and minuses. Single cell booster makes USB charging easy. It's more convenient and more compact when using removable cells. Dual cell buck gives you much higher output capability and wider voltage range. Dual cell buck also allows you to use lower drain protected round cells. Boost requires high drain cells.

so only if you want to be able to use ineffecient atomizer buck solution is preferrable ?

It's actually uncommon to hear first hand about someone experiencing a Li-Ion battery failure. What happended with your camera? I have a friend who experienced a Li-Ion failure on one of her e-cigs. It took off like a rocket from the charger spraying super hot electrolyte. Fortunately she was home when it happend and was able to deal with it. Might have burned down her house otherwise. All of the accounts I have heard first hand have been during charging.

i dont know as i just came in storage for work, and there was smell and burned plastic. nothing fly anywhere but there was mark on iron shelf for long time lol. this was before lithium was common so i was a bit put off by it as i didnt know it could happen. it allways got hotter than others when charging, so it might have eventually cracked inside from many cool-heat cycles ?

 

[CraigHB]

is it resonable to think that failure happens as a factor of thermal stress+chemical wear, rather than as a factor of charge rate, so that if thermel stress is lowered with lower internal resistance nanotech then higher C charging does not increase failure risk noticably?

Yes, you'd think a battery with a higher C rating would be less prone to failure. There are several failure modes and one of them involves internal mechancial failure. The other involves chemical failure. Both seem to happen most likely during charging. A cell with a higher C rating has thicker plates and insulators making mechanical failure less likely. It also has a more stable chemical composition to tolerate higher currents.

so only if you want to be able to use ineffecient atomizer buck solution is preferrable ?

In terms of electrical efficiency, buck and boost are similar. The only physical difference between them is where the switch, inductor, and rectifier are located in the circuit. I don't think there is a notable difference in efficiency as far as juice consumption from one atomizer to the next. Probably some, but not worth getting picky about. It's a fairly linear thing, the more power you use, the more juice you consume.

 

[srolesen]

cool, so high C batteries are likely to be safer and last longer, i like!!!
seems their allso likely to be bulkier, eeew lol, oh well

for atomizer effeciency i tried to calculate it if i remember correctly it was cartomizer like boge ones around 15% effecient and ce2's around 20% (i meassure how much vaporized juice untill battery was depleted and calculate from physics book how much energy should be needed)

i still dont understand this buck/boost stuff, if it is same basic method for both, how come so many people use buck ?

 

[CraigHB]

i still dont understand this buck/boost stuff, if it is same basic method for both, how come so many people use buck ?

There's actually a whole bunch of different types of switching regulators also known as DC-DC converters. Buck and boost are the more common ones. Buck can only lower voltage, boost can only increase voltage. There's also buck-boost that can do either one as required. For modding, you can get buck modules or boost modules. These are complete regulator units ready to plug in and work for you. I have not yet seen a buck-boost regulator in module form, but the converter type is employed in production mods like the Pro-Vari and LavaTube. The converters in those are designed from the ground up specifically for the device.

Buck is probably more popular for modding because it has the highest output and widest voltage range. Since it reduces voltage, current demand on the battery is lower. You can use smaller protected cells. Also, there's a much wider selection of buck regulators than boost regulators because buck is more commonly utilized in consumer electronics. The down side of buck is it requires two series cells which makes built-in USB charging problematic.