Question about Petit Crouton L battery formulation preferences

[Arkhan]

I've read in the PC.L user manual that LI batteries are recommended. I've also read the written voltage range for the board, with 4.5V being at the bottom.

My question is: Does the PC.L actually have a strong preference for the higher voltages of Lithium Ion rechargables, or is the blurb in the manual just a recommendation?

Here is an example of a situation where NIMH might be, at least on paper, a better fit.

4xAA pack. With NIMH, you can achieve 4.8V and ~2200 mah with plenty of discharge rate and a very low price point. With LIon, you can achieve 7.4V and ~1800 mah.

If the PC.L would really be (louder, better, happier) with 7.4V, or is the 4.8V solution just as good with a smidgey more runtime. I understand that the LED driver on the PC.L is not a voltage chopper, so perhaps the 2200mah vs 1800mah is not an apples to apples comparison due to the voltages.

Somewhere, someone commented that the audio amp on the PC.L really comes into its own at/above 6V input voltage, and if that is the case, then LIon may be preferred for that very reason.

Its too bad that there is such a jump in capacities between the 14500 and 18650. I know there are physical sizes inbetween those, but capacities don't seem to make them attractive choices.

Don't get me started on LIon AAA batteries, which are apparently oversized Tic-Tacs with a protective PCB attached.

Those sabersmiths who have had access to the PC.U for the past year-ish, what are your experiences between the two battery formulations?

Any input would be appreciated.

[FenderBender]

I have used the PC successfully with 3.7V Li-Ions as long as it is a red/amber LED and no issues with volume. It IS louder with 7.4V I will say though. You can get 18500s for more runtime than 14500s with shorter pack length than 18650s. Or you can use 14670s as well. Lots of options for Li-ion solutions. I would stick with Li-ions on the PC. The driver is so good, mah on the batts aren't everything;)

[Azmaria Dei]

i've always heard it said that a 7.4V Li-Ion pack puts the CF and PC right at their 'sweet spots' on power. and since that advice has come from a lot of highly experienced smiths that i trust, i'm going to go with that info.

[Takanis]

Good topic here. I was curious about this myself. I've heard the same thing that Azmaria said, but I've seen people run them on Reds with 3.7v. Good to know. Thanks guys!

[Skottsaber]

Yep, and it is mainly to do with the audio amp. From having done some R&D with them [small audio amp chips] before, that 6v point makes a ton of difference.

[jedimastergarcia87]

I was also wondering this. Thanks for the info. I will be using a blue rebel led with my PC-L when I get it next week. Should I be fine with two 14500 li-ion batteries without the pcb board or is that needed for the re-charge?

[Skottsaber]

To build a pack you will need 2 unprotected 14500s and a protection PCB.

[xl97]

I was also wondering this. Thanks for the info. I will be using a blue rebel led with my PC-L when I get it next week. Should I be fine with two 14500 li-ion batteries without the pcb board or is that needed for the re-charge?

are your 2 cells re-chargable and protected cells?

if so..you dont 'need' a PCB ..

each cell has its own built in protection.

that being said..the general 'attitude' about using pre-protected cells without a PCB for your 'pack'.. is that the drain and re-charge of the cell wont be uniform.

meaning 1 cell could charge up full before the other does.

[Jucksta]

I thought I knew what I was doing... but as I have all of my components in front of me, I realize there are a few things I need to be clear on.

I have a PCL, and 2 3.7v unprotected li-ion batteries (in a holder) as well as the PCB. I'm a bit confused about wiring the PCB since it has the plug w/ 2 wires running off which I wasn't expecting. Also, today I wasn't going to wire the recharge port because I don't have a decent plug for when not in use.

Now I'm wondering if I can just run the li-ion batteries I have directly to the board since I will recharge them outside of the hilt. Alternatively should I just get some protected li-ion batteries. Waiting to fire up my set up will be painful, but not nearly as harsh as frying my board. Burning out an av switch was painful enough when I put the resistor in the wrong spot.

Suggestions? Links to other threads?

[Skottsaber]

In this post (http://forums.thecustomsabershop.com/showthread.php?12829-Li-Ion-Battery-Packs&p=199373#post199373) I detail the wiring of the PCB and what to do with that connector.
For a Petit Crouton is is highly recommended that you make a soldered pack instead of using a holder, as on a hard hit your batteries will lose very slight connection with the springs and the board will reset.

As for a kill plug/key, you can always use the plug that comes with your charger or a 2.1mm DC plug to kill power. The reason most kill keys we use are plastic is just precautionary (so as to not short the batteries or perhaps not even kill power), and while they are again, highly recommended, it isn't necessary for them to be 100% plastic.

[Jucksta]

Thank you so much. I scanned over it... I'll obviously need to read through very carefully as I actually do the build. So my remaining question would be whether it is safe to power up my PCL w/ the unprotected batteries in the holder, just to test it out. No hitting anything, I don't even have a blade at this point.

I also haven't purchased the smartcharger yet, next on my wishlist.

[Silver Serpent]

Yes it will be safe to power it that way. The protection circuits are only needed when charging the batteries. Make sure you put them on the charger before using them at any rate, as they don't come fully charged.

[Skottsaber]

Yes it will be safe to power it that way. The protection circuits are only needed when charging the batteries.

That is incorrect. It is dangerous to use Li-Ion cells without protection. The protection board not only helps regulate charging but also prevents the cells from dropping 5A loads at a time (something they love to do), and overdischarging.
Always use protected cells/packs when using Li-Ion.

[Jucksta]

I'm stalling on building my battery pack, since I'm not really sure what to make tabs for them out of. Any suggestions? With all of the stuff I have sitting around here, I can't really find anything with conductive strips of metal to salvage from them.

[Silver Serpent]

I stand corrected, Skott. Thanks for catching that, my brain doesn't come on all the way during the weekends.

[Sunrider]

I'm stalling on building my battery pack, since I'm not really sure what to make tabs for them out of. Any suggestions? With all of the stuff I have sitting around here, I can't really find anything with conductive strips of metal to salvage from them.

Errmmm... Dude... You buy cells with tabs on them. You don't mount tabs yourself. ;)

[Crystal Chambers]

Tabs? Like in a battery holder? When making packs you'd normally solder directly to the battery. If you're not comfortable doing so (not the safest way to go) then you can buy cells with tabs on them and then you can solder to the tabs. Have a look around the forum for tutorials on it otherwise....http://www.youtube.com/watch?v=wSp9hRKkYDM

[Jucksta]

I guess I will post here since I've already asked a few questions regarding the PCL. So I initially tried setting it up with an illuminated av switch, but there was no action. Now I have it wired with a simple momentary switch, but I cannot get it to respond in any way. Will the PCL function off 3v? I'm just running 2 AA batteries until my protected li-ions come in.

[Sunrider]

I think it needs at least 5 volts.

[Skottsaber]

5v is only for CFv5.

I think that the minimum PC will work on is about 3.3v.