US v2 battery options?

[burllyandy1@comcast.net]

Hello all. I've been lurking for awhile, but this is my first post. I'm starting to get all the pieces together for my first MHS saber. I've got a US v2 pre-ordered and would like to run royal blue K2. Will the 4AAA battery pack be sufficient for this or do I need more juice?

[xwingband]

It'll run it.

As a rule of thumbe you should take the forward voltage of your LED and then add a volt for your minimum battery voltage. 4.8V if you put rechargeables in there would be just about enough, 6V of alkalines even better.

The only caveat is that a K2 is 1.5A and AAA's are around 1000mAh. This means you'll be getting sub-1-hour runtimes. I would suggest that if you can fit AA's that you should.

[burllyandy1@comcast.net]

Thanks for the answer Xwing. Looks like I'm gonna try to fit a AA pack.

[LordMasoch]

You can get a pack pretty cheap frmo the shop. $16 for a AA 2600 mAH pack. http://www.thecustomsabershop.com/48V-AA-2600mAh-NIMH-Rechargeable-battery-pack--P170.aspx

[burllyandy1@comcast.net]

I don't have an abundance of room in my hilt. The main body consists of a 3" double female MHS section and the v-grooved ribbed extension. I was thinking of switching to a Lux V and picking up some Ultrafire protected 14500 Li-ions at 3.6v and 900 mah and using them in a 2AA holder from Radio Shack. Someone was talking about this setup on the FX-Sabers forums, and it should provide enough power. I wonder if the PCB's on the individual cells will still do their jobs while being used in a 2AA holder though.

[MoonDragn]

PCBs? Those cells are 36 mms long. Would two of them fit in a 4 of them fit in a 2AA holder?

[burllyandy1@comcast.net]

The guys over at Fx-Sabers seem to think that they'll fit. The 14500's are supposed to be the same size as AA's. I imagine that the PCB adds a little to their length, but I don't think that it would be enough to keep them from fitting in a spring-tensioned AA holder.

[xwingband]

PCBs? Those cells are 36 mms long. Would two of them fit in a 4 of them fit in a 2AA holder?

No, the third and fourth digit is the length. It's 50mm's. Same as an AA cell.

My advice would be that you remove them from the holder any time you aren't using it for a while. I once experienced on a set of cells that the spring pressure made the cells leak. That made them useless.

Going back to what I said earlier that a volt extra is best, a Lux V + will work but not all that well. I prefer more juice, but you are right that you don't have a lot of space and you're limited.

[burllyandy1@comcast.net]

What about a pre-made 16850 pack. They're 7.4v and between 2000 and 2600 mah. I don't think that pack would fit inside my ribbed extension, but if I reversed my internal design, it should fit into the 3" double female section. I really should have designed my internals first, but seeing how the US isn't available yet, that wasn't really an option. I may just go Lux III to keep things simple on my first saber. I still haven't found a switch that I like either. I really want an Obi TPM style red button, but have never seen anything even close. Oh yeah, thanks for the info guys.

[eastern57]

2x 18650 packs (side-by-side) do not fit in any MHS pieces, they would have to be end-to-end.

They're a different challenge to say the least, but they're my prefered cell. If a CF with a standard size SD card can fit on top of one, then I'm fairly certain that an ultra sound would be able to also - even though I've never seen one in person :rolleyes: :p

edit: for Li-ions, pretty much the only cell that can fit side-by-side are 14500s - and those are good too. Don't be detered by the 900mah label... it still lasts for a [relatively] good amount of time.

[Strydur]

We will have a new speaker mount/battery holder combo coming out one of these days which will allow you to hold the 2 14500 protected cells and should allow the US2.0 or other sound modules to stack on top of it. So for just a little over the length of a AA you can have 7.2v, speaker, and sound module. I will try and get these done by the time US2.0 is out.

[Master Dru-Er]

Wow excellent I was just about to take the plunge on a battery selection for US 2.
*anxiously awaits*

[xwingband]

Well, there you go... then you can put another set in the grips. Automatic double of power. :)

[burllyandy1@comcast.net]

That sounds awesome Strydur. I'll be first in line for that setup.

[beggarsoutpost]

Yeah..really looking forward to this part...great to here something like this is getting made.....

[Jase Kala Maris]

any word about this battery pack/speaker combo, I'd love to add one to my order to be sent out with my USv2.0 board...

[Skaboom]

any word about this battery pack/speaker combo, I'd love to add one to my order to be sent out with my USv2.0 board...

I second this. I am really looking forward to my US board on it's own, something like this will make my hilt much neater and easier to maintain. Hopefully we can get some word on this soon...

[Strydur]

I am going to try and have it ready in time but no promises.

[Skaboom]

Awesome, Thank you very much Tim!

[Hasid Lafre]

14500s - and those are good too. Don't be deterred by the 900mah label... it still lasts for a [relatively] good amount of time.

So how long is a relatively good amount?

[Novastar]

Hasid, it's difficult to tell once you start figuring in:

* How much the LED draws
* The flicker / PWM settings
* The sound itself -- basically, the speaker
* The variance the cells will have

But, in general--that is what the entire IDEA is of a "mAh" rating. If something is rated for 1000mAh, it means that (generally) if you draw 1A consistently from the cells, they will last 1 hour.

If something is rated for 500mAh, it means that (generally) if you draw 1A consistently from the cells, they will last half of an hour.

Most current Li-Ion 18650 single cells have about 2200mAh to even up to 2600mAh. So, obviously, drawing around 1A all the time would yield something like 2.5 hours of usage.

Again, this is all GENERALLY speaking. I honestly have no idea what the "true" draw is on my CF sabers, since:

* They are always flickering and pulsing on my modes when on...
* They are not always pulsing/flicking in the same fashion (hum vs. lockup, etc.)
* They are not always on for 2 hours straight with no respite (pretty rarely actually)
* The sound is for 36mm and 45mm speakers
* There are 4 indicator LEDs drawing current in weird and random ways
* There is a vibration motor in both of them, mimicking the main LED current

Still... with all the added gunk and weirdo things going on, I imagine they last well over 2.5 hours. Maybe someday I'll test this again, but... it's sort of a waste. They last a long time on any cells >= 2000mAh.

[Jedi-Diah]

So, would a 4.8V 2600 mAh pack last longer than a 7.2V 1100 mAh? I just picked up the 7.2V pack at a local hobby shop for $10 and its about the same size as the 4.8V pack from TCSS. Both are NiMH.

Does increasing the voltage translate into longer run times if the mAh remains the same? Or is the additional voltage that you dont' need (let's say the LED I'm using is around 3.8V, 1000ma) unnecessary and wasted?

[Novastar]

Heheh, this is EXACTLY part of my point... it starts to get REALLY confusing once you start figuring in:

* Ok, the LED driver is a "step down" driver, regulating CURRENT...
* Ok, the LED itself wants (for example) about 4v...
* Ok, the Batteries are actually MUCH greater voltage than the LED!!

This all adds up to yet MORE ways "run time" can mess with your mind and f you all up if you're trying to get a super-accurate idea of such run time.

I was about to say a lot more, but... let's just say for a "step-down" driver setup (like CF, buckpuck, US board)... using a battery setup that is something like 1v to 3v greater than the LED's fwd v... will produce a bit more runtime.

Not like... an extra HOUR or something... just... more. :)

[Jedi-Diah]

Hi Novastar,

I don't expect any real accurate figures. Just general principles.

I guess my basic question is this:

Is there any good reason why I should use a 7.2V pack if I'm not using a Lux V? If all the LEDs I'm going to use are in the 2.9V - 3.9V range, is there any reason to use more than a 4.8V pack?

If not, I'm just going to concentrate on the highest mAh 4.8V pack that can fit in my hilt (2700 mAh) and not worry about any higher voltages if there is no substantial advantage.

Thanks for your patience.