Batteries. Chinese VV PV's. Vendors. This is what I know and what I believe.
by, 01-29-2012 at 07:00 PM (1278 Views)
I'm posting the following as a blog entry rather than in the open forums because I'm not a modder, engineer, or anything that would traditionally qualify me as an expert on these subjects. If you read what I have posted below and disagree, that's fine, but I'm not interested in defending my informed opinions because some might argue that I don't have the proper background to form and express said opinions. I do have a college degree from a reputable university, so at least I'm trained to competently research, absorb, and interpret data. I've done a lot of reading and have formed some opinions. Here are some of them:
Just some additional info on batteries for those that would like to know more:
ICR 18650 = lithium cobalt oxide (traditional) cylindrical cell
IMR 18650 = lithium manganese oxide cylindrical cell
IFR 18650 = lithium iron phosphate cylindrical cell
ICR are your Lithium Ion batteries that have great capacity (higher mAh) but require a Protective Circuit Board (PCB) for safety. A PCB is basically a circuit breaker that shuts down the flow of electricity if too much is going in or out of the battery. The PCB is needed because there is a high resistance to the flow of ions when these batteries are charged and discharged. PCB's can fail and the user would never know it unless the battery goes into thermal runaway. The result is lots of heat, venting of gasses, and possibly FLAME. That's why venting holes in mods are so important. If the gasses can't escape, pressure builds up until it explodes. When using protected Li-ions in a PV, always go for high quality, reputable brands like AW, Panasonic, and Redilast. Any protected Li-ion bought on dealextreme is only good for a flashlight with a low amp LED bulb, in my opinion. Trustfire and Ultrafire are distributors, not manufacturers. They'll slap their heatshrink label on any battery, including recycled cells and factory rejects. That's why they can be had so cheaply. Their mAh ratings are vastly overstated, too. AW is a distributor as well, but they install PCB's and heatshrink their label on to Panasonic cells. I'll take AW any day of the week. The AW 2600 mAh protected ICR battery is the best choice for a PV if you're wanting a protected Li-ion. They outperform the AW 2900 and 3100 mAh batteries for our uses. The high mAh batteries only last longer in flashlights with low amp draws. In PV's, with higher amp draws from our LR atties, the AW 2600 is as good as it gets.
IMR batteries are vaunted as "safe chemistry" and therefore don't require protection. This is true. The ions in an IMR battery flow much more freely, making them ideal for devices which want to draw a lot of amps, like Provaris and Lava Tubes. IMR batteries can short out and go into thermal runaway too, but they just produce heat and gas. No flame. Venting is still important and burn injuries are still a possibility. Provaris and Lava Tubes are supposed to have protections built in to cut the flow of electricity if they detect too much current coming out of the battery, but in a worst case scenario, your PV would get too hot to hold. If it's in your pocket, make sure you can easily fish it out if you feel it getting warm. As long as vented gases can escape and not build up pressure, there's not a huge safety risk.
IFR are also known as LiFePO4 and are also safe chemistry, but are limited to about 3.2 volts nominal due to their chemistry. This is why they are commonly used in stacked pairs of RCR 123a cells for 6 volt vaping. Stacking batteries in unregulated mods like the Silver Bullet, Omega, etc., is just not worth it, in my opinion. You have to take care not to over discharge them and also make sure your charger is compatible with LiFePO4 batteries. Also, the battery closest to the load will discharge much faster than the one "on bottom" so you have to take care to flip the batteries after every recharge cycle. That is, the one that was on top during the last use, should next be placed on the bottom after the pair is recharged. You also need to measure the voltage on each battery after every recharge cycle. If each battery in a pair don't have close to the same exact voltage after recharging, the potential for battery failure goes up considerably when using them stacked. As always, adequate venting in your PC is imperative. I, myself, would only use stacked batteries in a regulated mod with built in protections, like the Buzz Pro or Infinity Pro from notcigs.com, personal opinions of Mike and his company, notwithstanding.
When the LavaTube was first marketed by Volcano, the manufacturer/distributor that sold the Lava Tube to Volcano also sold them counterfeit AW IMR batteries. When Volcano was informed that what they were reselling to their customers were, in fact, unprotected lithium cobalt batteries (holy ...., that's not safe at all), Volcano had to scramble to make it right. This just goes to show you that some Chinese companies have no scruples when it comes to making sales, so beware of what you're buying and whom you're buying from.
Now multiple North American vendors are selling Lava Tube kits under multiple names. The batteries that come with these kits are an unknown factor and I would not trust to use them in any PV. The vendors are all about making a buck at this point and cashing in on the VV craze while they can. I have no problems with them selling the mod at their ridiculous mark ups, but selling these mystery batteries and cheap ass chargers with them is beyond irresponsible.
If anyone asks me, I'll them to buy the mod alone and then go to RTD Vapor or Super T Manufacturing to buy genuine AW IMR batteries and a TR-001 charger. If they have concerns about chargers and don't mind spending more, the XTAR and Pila chargers are both highly recommended.
TL;DR: If you aren't willing to take the time to educate yourself about the batteries we use in PV's, you should probably stick with a low mAh starter kit. The vendors are no longer trying to inform you what is best and safest to use. They just want your money. Too bad they couldn't follow Provape's example. FYI: I've never owned a Provari. Maybe someday...