The ABCs of batteries

[Sumratio]

@Rocketman I knew the resistance in the math was not going to match because of the internal resistance of the battery but I am not sure of the math or of a way to compensate for the internal resistance. Also the voltage of the batteries is what they are fresh off the same charger.

I finally got another IMR to check out but it is a BDL and I have to say they are garbage compared to the AW unless I have a dud, which I might. Here are the numbers with same setup as before:

BDL IMR 14500 Resting charged voltage=4.11VDC, Load Voltage=3.40VDC, Current=1.61A, Wattage=5.44W

Like the numbers, it is performing much more like the Ultrafire than the AW IMR.

 

[Rocketman]

Is there a chance your meter is acting up?
Granted the Ultrafire is a crap cell
but the 2.9 to 2.0 ohm shift seems strange.
Often a cheaper DMM will have very different voltage, current and resistance accuracy.
I get pretty much the same voltage for all cells run through a charger. Terminating charge at 3.99 for one cell and 4.16 on another sounds odd.
Your meter got a good battery in it?

Check things out. This is a "sticky".

 

[Battletroll]

Anyone got the updated charts that are removed or a link for them?

 

[Bejeebus]

I have a question about charging - I have a nice Pila IBC 4 stage charger that I use for IMR 18650 3.7v 1600mAh - ie: it has long slots for these bats. I find that I mostly use a mod that requires 2 smaller batteries: RCR123A 3.6v 650mAh. My problem is that even with the extender included in the Pila the RCRs are too stubby. Today I realized that I can stack two of them into one slot. Will this work>>or is it a 'no no'?

If a nono, what can I use to decrease the space in the Pila slots? I have a trufire charger that will hold the little guys, but I am not convinced its doing its charging job and, hey, the Pila is never being used -

Any advice = greatly appreciated!

 

[Killjoy1]

No, NEVER stack batteries in a single slot of any charger!

Magnet spacers can be used for charging shorter batteries if you can get one the right length. There's also a guy on a flashlight forum somewhere that makes custom battery holders for use in the Pila, but I can't recall the name right now. Google "Pila adapter" and you should be able to find it

Why do you think your other charger isn't doing its job? Do you check the batteries with a multimeter after charging?

 

[Bejeebus]

Well no but now that you mention it I guess an multimeter investment is a good idea. Thank you for responding!

 

[Killjoy1]

Definitely a good investment You should be able to get a cheapie for around ten bucks that'll do what you need. It's the best way to be sure your batteries are fully charging and aren't over-charging. It really doesn't seem like a big deal, but it's a good way to help prevent that one in a million chance of a battery failure, particularly in a stacked battery situation so you know they're both charged the same when you put them in your mod.

On the spacer thing, I know you can use magnets like these, but I don't know if there are any particular things to look out for when doing so. The largest ones I've used for any reason were much smaller than would be suitable for your batteries in a Pila. There are a few vendors that sell different size magnets

I also found the custom battery adapters I mentioned above: charging adapters to fit ANY SIZE li-ion into an 18650 charger (Pila IBC or other)

 

[Rocketman]

Magnets are used in some flat top multi-cell applications but have one inherent problem to watch out for.

The Positive contact of the cell is steel, and magnetic. SO IS THE NEGATIVE SHELL. You have to be careful that the magnet does not slide off center and short out the positive contact to the negative shell. If it gets close, the strength of the magnet may pull it over the rest of the way.

 

[slimest]

There are another problems with magnets: if you put a construction with a strong magnets to your pocket, you can damage your credit card etc.

 

[byronchurch]

Very Helpful Thanks!

 

[Skyway]

What do terms like 1S01 mean when looking at batteries? Is there anyway to tell the "C rating" from this or is it just saying it is one battery or something?

 

[Koman]

Good stuff, thanks!

 

[Eli Ellis]

Thank_____It's______Over____Done______!
______God____Finally_____And_____With__ 8-o

Sorry, I couldn't resist.

Roflmao!! I will have to steal that sometime. Love it!

But while on the safety part of the issue, did anyone mention about letting the battery cool down before use! Or is that a myth too?

 

[dr g]

Question -- are the batteries that typically come with cell-phone powerbank devices usable for mods?

 

[ElectricalSocket]

Roflmao!! I will have to steal that sometime. Love it!

But while on the safety part of the issue, did anyone mention about letting the battery cool down before use! Or is that a myth too?

Nooooo not a myth. If the battery is noticeably warm, let it cool off first.

 

[WattWick]

What do terms like 1S01 mean when looking at batteries? Is there anyway to tell the "C rating" from this or is it just saying it is one battery or something?

Sure it's not 1S and 1P (not O)? In that case, it's the number of cells wired in either Serial (add up voltage) or Parallel (add up capacity). If it's single-cells and an actual O, I have no idea.

This thread is excellent. In more ways than one. Lots of useful info, some drama, the historical aspect, and ways to avoid blowing oneself up.

Thanks a lot to all contributors!

Fun "fact"; a "battery" is nothing in particular, just a configuration of "something". E.g. rocket battery. Or a battery of (galvanic) cells for storing electric energy.

 

[xpackaday]

Here a few thoughts. Most of the mod's you buy have protection built in for shorts and min voltage. The real concern is the battery charger. If you buy a charger you need to read the spec's. Most of the better chargers have protection built in. Limit to max voltage, limit to how low a battery can be before it will not charge it, short circuit, max charge rate etc.., and a shut off when full charged.

So, if you have a good charger, leaving it on the charger when it's finished is OK because it is not charging. The real problem comes when you buy a cheap one or those kits that are 2 - 18650 batt's and a charger for 9.99. It may be ok, maybe it's overstock. Or its junk.

All good batteries you should be able to find the specification. You need to make sure that the battery you are buying can handle the discharge rate you will be using. If your vaping at 12 watts on a 4V battery, you are pulling 3 amps. That's almost a short, so make sure the spec's support a 3 amp draw.

You make it sound like lead acid batteries are safe. There have been to many explosions with lead acid. You have the same problem with lead acid batteries. Buy a cheap charger and you over charge the battery because it never stops charging and you boil the acid and it develops hydrogen and explodes. Or drain the battery and cheap charger applies way to much current and the battery explodes or the charger starts on fire.

So I think something that would be useful would be what specs at a minimum you should be looking for in: a mods, batteries and chargers.