Li-Ion/Polymer 3.6v batteries... your experiences?

[Eco]

Would the concept of using the external pack and zener diode work with a NiMH setup as well, providing the external pack is obviously also NiMH?

I know Nova's kind of the Li-Ion expert, but I don't know if we have a NiMH expert here. Lol

[Novastar]

I'm definitely no expert, lol. Far from it.

As to NiMh--when you get right down to it, voltage is voltage is voltage is voltage. Sure, cell types differ, but 12v "alkaline" is still essentially 12v "Li-Ion" and so forth. It doesn't mean you should mix battery chemistries... no,no,no... but it DOES mean that the energy is the same.

Now, Ni-Mh have a lot more "output power" than most standard Li-Ion cells. On Li-Ions, the PCB limits the output (~4.2A) to prevent the cells from becoming dangerous. Ni-Mh are different, since in this case they can take a larger strain on output (>5A) for the mostpart.

I learned this from Edwin (Eandori) in the past. He applied Ni-Mh cells in RC-racing, because you could get some CRAZY "boosts" of speed from the cells. Versus using other cell types.

But anyhow... yup, the diode would still need to be there. In fact--maybe MORE SO because of the fact that the cells are made to output a truckload of current if the situation was "wrong enough". Therefore, additionally, you would definitely need more protection on the "charging pack" to put a gate/limit on how much current would be allowed to flow.

When you get right down to it... GENERAL cell charging is something like "CCCV" (constant current, constant voltage). Each cell type differs, which is why you will see "Li-Ion" chargers and "Ni-Mh" chargers and so forth.

If you had a dedicated power supply + the RIGHT KNOWLEDGE... you could recharge most any cell that was made to BE re-charged. Because you could provide the precise CCCV setup.

Anyhow... again--not to be duh pahtee poopuh, but... I am advising *against* making a "battery to battery" charge pack. Not that I think it cannot be done... but only because:

* Honestly, WHEN are you in a situation SO dire... that you can't get to a power outlet with your saber??!? Are you REALLY ~that~ addicted?!??!

* When the possibility exists to: A) swap cell packs and have saber running in 10-15 seconds... B) charge current saber with "special batt pack" and wait 4-8 hours... ... ... WHEN in Zeus' holy place in the clouds would you choose option "B"?!?!?!?

* This requires fairly decent electronics knowledge. Also--it's still a dangerous experiment. One wrong move, and ~poof~ ... it's fire time. Possibly explosion time. No bueno.

* My Li-Ion chargers really aren't all THAT much bigger than a battery pack. Sure, they're bigger, but this isn't to say that they are SO horribly "non-portable" that they would come with you to some event with any more difficulty than another battery pack.

Finally, I'd say that maybe waiting for WiLectricity (which is actually already HERE) might be even better, heheh!

[Rhyen Skytracker]

I say the best thing to do is make another saber. That way you won't have to worry about charging batteries, just grab your other saber. LOL

[Kant Lavar]

Oh, granted. (Actually, if I really wanted a portable recharging solution for an in-hilt battery pack, my battery charger can run off a car battery!) And personally, I like being able to just swap out Trustfire cells quickly - in fact, when I troop in my Jedi costume (if/when I actually get the belt!) I plan on having an extra pair or two of charged batteries ready to go in one of my belt pouches.

It's just kind of an interesting thought experiment.

[Eco]

Why make a battery-battery charger?
Because we (theoretically) can.

[Jay-gon Jinn]

Oh, granted. (Actually, if I really wanted a portable recharging solution for an in-hilt battery pack, my battery charger can run off a car battery!) And personally, I like being able to just swap out Trustfire cells quickly - in fact, when I troop in my Jedi costume (if/when I actually get the belt!) I plan on having an extra pair or two of charged batteries ready to go in one of my belt pouches.

It's just kind of an interesting thought experiment.

This is what I do....and if the back up batteries die on me, I usually have 3- 5 back up sabers with me too.

[Novastar]

A snippet of a recent post I made. I thought it was a fitting thing to add here... for anyone wondering about Lithium Ion cells in general.

I will also note... I don't think Lithium Polymer is a very good idea for sabers. But, I put up the poll a long time ago. Sorry for that!

---------------------------------

http://en.wikipedia.org/wiki/Lithium-ion_battery

By the way, here is a bit on Lithium Iron Phosphate cells (LiFePO4).

http://en.wikipedia.org/wiki/Lithium...sphate_battery

As a matter of note... Lithium ION cells--don't really even have the metal "Lithium" in there. Because it's in ionic form. You can see this in the above link--it just says it in a more scientific way.

Also, Lithium primary cells... unfortunately ARE using the metallic compound or whatever of Lithium. These shouldn't be confused with Lithium-Ion! Although it would be easy for a n00b to do so...

Finally--although it can be found in the above links--Lithium Ion is a 70's (!) technology... and LiFePO4 is a 90's technology. This doesn't mean that Lithium Ion tech is "old school" and out-dated though... it only means that Li-Ion has seen 30 years of (successful) development. And that LiFePO4 still has places to go.

Whether or not LiFePO4 ends up being the "best in show" over Li-Ion remains to be seen. What I think is cool is... new techs and solutions are always changing/improving.

[TroyO]

It's actually pretty simple to make a charge-on-the-go pack. Get a "12V" charger for 7.4 Lithium Ion packs.. IE:

http://www.batteryspace.com/customiz...connector.aspx

Get a 14.4v NimH (Or Li-Ion, or even use an Alkaline 8-10 pack... or even a 12V sealed lead acid pack, your choice really) pack, such as:

http://www.batteryspace.com/nimhbatt...nimhcells.aspx

or http://www.batteryspace.com/customli...11pid4901.aspx

Gut the one, hook to the other and bingo... you are all set. Because you are powering the charger and not the other pack directly it should work like a charm. You should get about 1.5 to 2 charges of a 7.4v, 2600 mAH Li-Ion pack from it... more or less depending on the pack you get.

Note that charging voltage for a car is 14.4V, although the batteries are nominally "12V"... which means any charger designed to run from car voltage is generally good from about 11V-15V.

So... there ya go. Get a cheap wall charger for the 14.~V pack of choice and you are set to go for less than $150 bones.

[Novastar]

Not to resurrect the Li-Ion situation, but... here's a question/observation I'm wondering about...

Ok... so you bought your Li-Ion cell/cells. You did this in 2005/2006. So, of course you are expecting that SOMEtime soon enough... the cell(s) will no longer hold (an acceptable) charge...

Have you ever experienced that a cell/setup would:

* Suddenly stop working (even if you check it with a charger)... but after a day or so, you're able to give the sucker a fairly decent charge

* General "flickering" from the cell/pack... even when the saber is NOT set up to flicker (meaning basically the current draw is unable to stay 'stable')

* Obvious decreased runtimes, yes...

Anyhow... just wondering! The point of this is--most of us who started using Li-Ion (in sabers)--did so no earlier than 2005 or whatnot... so it makes sense that few people have had their cells SO DARN long that they would already be nearly dead (permanently).

Thoughts/experiences?

[Novastar]

* BUMP? *

Dang. It figures. I ask ONE question of my own for once and all I get are crickets, hahahahahha :P

May the fourth be with you all... lol