Hi everyone!

[Lis]

Hi everyone, glad to join VT.

As a new member, I have a question about mod rechargeable batteries. what is different between IMR and ICR batteries, and which is better for mechanical mods? I just want to get a nice vaping, so i need some good advise. Thanks in advance.

[Christopher]

What you're actually talking about are product codes. Let me copy and paste this from CreigHB (I've quoted this before) It's 4am and easier than typing it all out

IMR is a product code. "I" stands for Lithium-Ion, "M" stands for the Manganese based chemistry, and "R" stands for rechargeable.

ICR is again a product code. Same as before except "C" stands for the Cobalt based chemistry.

Only the round cells commonly use these designators. There are flat cells or prismatic cells that use a Li-Ion chemsitry, but it's usually polymer based (plastic). I've never even seen the code designator for that. Everybody just calls them LiPo cells.

High drain means that the cell can handle high output currents. ICR cells are usually limited to 2 times the charge capacity in output drain. So, for example, a 750mAh 14500 ICR cell would be limited to two times 750mA or 1.5A. This is why this type of cell must be protected. It has the lowest drain capability and the highest volatility or flammability in composition.

IMR cells typically have an 8C drain limit which is 8 times the charge capacity. A IMR 14500 with 600mAh can handle 4.8A. This chemistry is less volatile than the Cobalt chemistry and has much higher drain limits so they are typically not protected internally. Though, they should have some kind of external protection because they can burn too, just not as easily.

LiPo and prsimatic cells can range in drain limit anywhere form 1/2C to 60C. They are slightly less volatile than ICR and a little more than IMR. They are typically not protected internally and should have external protection electronics. These are the type of cells you find in digital cameras and cell phones.

Generally speaking, you only use an IMR cell when the device specifically calls for one. IMR cells are required for boosters (single cell VV or VW) because boosters require higher drain. With a booster, you're going from lower voltage to higher voltage. That means you're going from higher current to lower current.

IMR cells may also be required for unregulated mods if the cell is small. For example, you are limited to 1.5A with an ICR 14500. If you want to use an LR atty with a cell that size, you need an IMR cell.

In the end, the size of your cell boils down to what you want in run time versus size. That's always the big trade-off. If you want a smaller device with a smaller cell, you'll have less run time. If you want more run time, you'll have to tolerate a larger device with a larger cell.

Size numbers are based on a metric scale. An 18650 is 18mm x 65.0mm. A 14500 is 14mm x 50.0 mm. A 14500 happens to be the same size as an AA battery.

[Lis]

Thank you very much, Chris.