Breaktru Forum

eCigarette Forum => Battery => Topic started by: DjKiDD on August 15, 2014, 12:42:50 AM

Title: The biggest battery I could find...
Post by: DjKiDD on August 15, 2014, 12:42:50 AM
I'm thinking of making a build utilizing this monster...

(http://www.all-battery.com/productimages/lifepo4/30078%20LiFePO4%20Cylyndrical%20Cell%2040152S%203.2V%2015Ah%201x450.jpg)
(http://www.all-battery.com/productimages/lifepo4/30078-10C.jpg)

Normal Capacity   15,000mAh (0.5c)
Normal Voltage   3.2V
Inter Impedance    <=8mOhm
Maximum Charge Current   3C (45A)
Maximum Charge Voltage   3.65±0.05V
Maximum Discharge Current   10C (150A)
Discharge Stop Voltage   2.0V
Dimension   Diameter   40±1mm
Height   152±1mm

Datasheet (http://www.all-battery.com/datasheet/30078_datasheet.pdf)
Title: Re: The biggest battery I could find...
Post by: CraigHB on August 15, 2014, 02:26:42 PM
Yes, that's a large battery.  That's a LiFePO4 cell which has a lower nominal voltage.  That may or may not be a problem depending on what you want to do with it.

The energy density with those is not hugely greater than a lead acid battery in terms of volume, but they are better in terms of weight.   They are not particularly safe batteries either.  The claim is that LiFePO4 cells are a safer chemistry, but based on the instances I've read of fire with them, that doesn't seem to be the case.

The main problem with that one is finding a charger for it.  If you attempt to use a standard 3.7V Li-Ion charger, that cell will die a horrible death and probably take the house down with it. 
Title: Re: The biggest battery I could find...
Post by: DjKiDD on August 15, 2014, 11:57:15 PM
I was imagining making a giant mech mod somewhat as a joke... depending on how it works out. haha
My other idea was to make a battery pack out of a couple and have a nice portable hookah style vaporizer.

There really aren't any DC/DC converters that can take such a low input voltage, right?

I have a a Turnigy Accucell6 charger to charge it, so I'm not too worried about that
Title: Re: The biggest battery I could find...
Post by: CraigHB on August 16, 2014, 03:34:50 PM
Generally a booster can run off the voltages you get with a single one of those cells, but it may have trouble once you get below about 2.5V.  You'd have to use that TI booster module (it's the only boost module I've seen).  Depends on the minimum input voltage for that one.

You'd have a problem running two in series with a buck converter since input voltage would not be high enough to cover regulator drop-out with higher output voltage settings.  You'd probably have to run three of them in series.

Probably the best application would be for a mech with a single cell and an atomizer with resistance low enough to get the power you want.