NB V4 Led strip and sound wiring check

[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.
voltage.jpg

[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.tron disc.jpg

[PCModulus]

hey is this also ok? i only have a usb charger port.tron disc.jpg

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.

[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.
voltage.jpg

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.