NB V4 Led strip and sound wiring check

[Shriker1]

16323

is this ok? also suggestion for two wire recharge ports?

[bigkevin61]

A 9v battery will NOT have the discharge capability to power a “neopixel” strip.

This battery (http://www.thecustomsabershop.com/Panasonic-Li-Ion-18650-37V-10A-3200mAh-PCB-Protected-Rechargeable-Battery-P1282.aspx), or one with similar specs is recommended.

[Shriker1]

i cant see the picture or link. and the voltage regulater is rated at 3 amps

[bigkevin61]

The link is the word “battery” and it hyperlinks to the store’s product page for the ”Panasonic Li Ion 18650 3.7V 10A discharge 3200mAh PCB Protected Rechargeable Battery” which is here: http://www.thecustomsabershop.com/Panasonic-Li-Ion-18650-37V-10A-3200mAh-PCB-Protected-Rechargeable-Battery-P1282.aspx

You don’t have to use that specific battery, but you need one with similar (height amp discharge) specifications (specs).

Most people use 2 led “neopixel” strips (back to back), and the amp draw of one, 1 meter strip, with all 3 colors on (white) is around 8.6 amps at 5 volts (though most people use a 3.7 v Li-Ion battery, and the amp draw is a little less)

There is no way an alkaline 9v can discharge that much, regardless of the voltage regulator (which at a 3 amp, rating would be insufficient).

Besides, even IF a 9v battery could handle the output (which it can’t), at a typical 550 mAh capacity, one color “on” would get you less than 11 minutes of run time (the Soundcard draw).

[Shriker1]

my rerasoning for this battery is when it goes through the regulator (not the simple 3 prong electrical component. its much more technical) it will be 5 volts which the board can handle and i like the extra oomph it gives. in fact its not really a voltage regulator, its more of a Step down module

[Shriker1]

the 9 volt battery also isn't alkaline. its a rechargeable lithium ion and im only using one strip and about 95 leds

[bigkevin61]

Any battery has 3 characteristics, though the 1st 2 are usually quoted.
1) Voltage which = “push” or “pressure” of current it produces.
2) mAh or milliamp hour capacity = “capacity” or “reservoir”, essentially how much / how long it can provide power before being “used up”.
3) max discharge (in amps) = “width of the pipe” or “how much current” the battery can discharge at once.

The typical 9v battery doesn’t have a large enough max discharge to power a neopixel led strip.
Even the typical Li-Ion 18650 3.7V 2600mAh Battery (http://www.thecustomsabershop.com/Li-Ion-18650-37V-2600mAh-PCB-Protected-Rechargeable-Battery-Module-P672.aspx) sold in the store dos not have a high enough max amp discharge to power those strips.

[Shriker1]

a Typical 9 volt battery has average of 330 mAh, my battery has almost double the amps at 600mAh and with the step down module it will take the unused voltage and convert it to amps making 3000mAh

[minorhero]

I am building a LED strip (neopixel) saber next. But my understanding is that 2 strips are needed back to back in order to not have half your saber dark. Again I haven't done it, but unless you are wall mounting your saber with no plans of using it, you may wish to run 2 strips.

[Shriker1]

thats the thing, im not using it for a saber. im using it for a tron disc, but i thought this the best place to ask

[bigkevin61]

Ok but milliamp hours is a measure of how long the battery can power something, NOT how much amps it can discharge at once.

The most popular google search for Rechargeable 9v battery points to EBL brand products, but I cannot find a data sheet for the products I found.

I just read you are planing in using the board and led strip for a Tron Disc.
So, I’m guessing space is an issue (and factor in looking for a battery that isn’t a 3.7v Li-Ion).

If you have seen any of the forum posts for bench tests and completed neopixel strip sabers, you will see that even at 3.7v, the leds are quite bright (in the 144 per meter variety). Running them at 5v may mean creating a more complicated setup.

[Shriker1]

ok ill look that up, also as i said before, im making a tron disc like erv did, only simplifying it. trying my hardest to not use arduino boards and lights so im using generic ws2812b strips

[Shriker1]

This is something that i have found


(post from amazon review) by Ken M.: I did run a discharge test with a 117 ohm resistive load. The discharge voltage curve was basically linear from a start of 8.4 volts down to about 7 volts, that took about 8.5 hours This, to me, would be the useful life. The end of the curve was from 7 volts down to the cut off voltage of 6 volts, that part took about 20 minutes.

Keep in mind, this data was taken from the very first cycle of this battery. Li-ion cells will have a slightly greater capacity after a few cycles. My test results: Resistive load of 117 ohms, start voltage 8.5 v, end voltage 7 v, average discharge current 66 ma, battery capacity measured as 560 mAh.

These are made up from two Li-ion 3.7 v cells. They will never charge up to an actual 9 volts, 8.4 v is about it. If the device you are powering is OK with this voltage range (most are), then the EBL 9V Li-ion is a good replacement for a 9 v alkaline battery.
16324

[bigkevin61]

ok ill look that up, also as i said before, im making a tron disc like erv did, only simplifying it. trying my hardest to not use arduino boards and lights so im using generic ws2812b strips

Hey, good luck with the project!
My profile pic is a hand made wooden TARDIS, with lights and music, so I’m all for non-saber projects!

The 9v Rechargeable battery’s are not prohibitively expensive, and if you are regulating the voltage to the NB board to 5v (within the operating range), you can at least wire it up and give it a shot.

Look up some forum posts about neopixel issues (board cutting out; weird sounds from the speaker; boot ok, but cuts out on activation; etc) which are usually caused by un or undercharged batteries, OR batteries without the max discharge capacity needed, (protection circuits cut off the battery temporarily, like a circuit breaker in your house).

That way if you wire this setup and test, and experience any of those issues, you know what to look for (if it is battery related).

[Shriker1]

hey is this also ok? i only have a usb charger port.16325

[PCModulus]

hey is this also ok? i only have a usb charger port.16325

Still need a cutoff switch so the board never sees the charger, unless your step down circuit takes care of that.

[Shriker1]

i would imagine it would take care of that. though im only a hobbyist electronics man so i wouldn't know too much, but i am capable of understanding what i need.

[minorhero]

The regular 2.1mm recharge port sold in the store has a built in switch on it so that with the charger removed it bypasses the port. Your USB recharge port would need something similar. To my knowledge the board does not have this built in.

[PCModulus]

i would imagine it would take care of that. though im only a hobbyist electronics man so i wouldn't know too much, but i am capable of understanding what i need.

If theres not a physical disconnect, youll need something.


The regular 2.1mm recharge port sold in the store has a built in switch on it so that with the charger removed it bypasses the port. Your USB recharge port would need something similar. To my knowledge the board does not have this built in.

I use USB ports to charge and just use a simple on/off switch. Both batt and USB port negs go to one side so itll charge with the switch off. Just gotta make sure you dont leave it on when charging.

http://pcmodul.us/jeff/DSC00400.JPG

[bigkevin61]

This is something that i have found


(post from amazon review) by Ken M.: I did run a discharge test with a 117 ohm resistive load. The discharge voltage curve was basically linear from a start of 8.4 volts down to about 7 volts, that took about 8.5 hours This, to me, would be the useful life. The end of the curve was from 7 volts down to the cut off voltage of 6 volts, that part took about 20 minutes.

Keep in mind, this data was taken from the very first cycle of this battery. Li-ion cells will have a slightly greater capacity after a few cycles. My test results: Resistive load of 117 ohms, start voltage 8.5 v, end voltage 7 v, average discharge current 66 ma, battery capacity measured as 560 mAh.

These are made up from two Li-ion 3.7 v cells. They will never charge up to an actual 9 volts, 8.4 v is about it. If the device you are powering is OK with this voltage range (most are), then the EBL 9V Li-ion is a good replacement for a 9 v alkaline battery.
16324

Ok, this is someone measuring how long the battery takes to “use” it’s voltage. The “discharge curve” is not linear over time. (Ie, the battery may take longer to go from 8v to 7v than from 7v to 6v)
Batteries tend to not have linear “discharge curves”.

The key to this person’s review, is that he did this test while only drawing a paltry 66 milliamps.

Once again this test is not showing how many amps the battery can output at once. That figure is usually dependent on the physical & chemical makeup of the battery, and it is not infinite.

[Shriker1]

ok here is an updated version of the schematic.
16326
do you approve?

[bigkevin61]

ok here is an updated version of the schematic.
16326
do you approve?

The idea of a switch is to cut the board off from the circuit of the battery and USB port.
The USB port will not be part of a complete circuit until you plug something in, so haveing a switch in that circut doesn’t accomplish anything.

You want to place the switch on either line from the battery to the step down module, and open the switch before plugging in your power source into the USB port.

[Shriker1]

so like this?16327

[bigkevin61]

so like this?16327

I just realized you are showing a SPDT Switch, not a SPST Switch.

If you use a SPST Switch (open or closed are the only options) it can stay in that position.
If you want to wire in a SPDT Switch (basically think of a railroad switch, where one line breaks into two, you can direct the train to either based on the Switch position) there are multiple ways to do it.
One way would be to leave it where you have it in the diagram, and only wire the common post, and one out post, basically making it function like a SPST Switch (in the railroad example, one of the two lines is a dead end)
Another way to wire it would require you to rearrange the diagram, and it would be easier to draw that than try to explain with words.

[Shriker1]

so like this?
i removed the sd mod and replaced it with a ten amp battery cell.
16338

[Forgetful Jedi Knight]

so like this?
i removed the sd mod and replaced it with a ten amp battery cell.
16338

Yes, that looks better. The SPST switch will act as your “kill key”, correct? If so, your diagram looks fine.

[Shriker1]

ordered the new battery and switch

[Shriker1]

470 ohm 1/4 watt? or 5 watt?