Audiobox now running on 18650 Lion batteries

Discussion in 'Firing Systems And Fusing Fireworks' started by Dodgey, Jun 26, 2021.

  1. Dodgey

    Dodgey Pro Firer/Crew

    Had to use my backup / spare AB the other day and running on 3 x AA eneloops had me a bit twitchy - I've heard the AB can be a bit power hungry. My other AB runs of a large SLA battery but has developed a fault over the lockdown somehow.

    So yesterday I fitted 4 x 18650 Lion cells, a Mini USB charging port, and a small inexpensive single cell charger.

    Below - the 4 cells in a parallel battery holder (giving 16AH / 16,000Mah of capacity at 4.1v) and also the charger at the bottom

    2021-06-26 10.48.15.jpg

    Below - Mini USB charging port. I like mini USB - much more robust than micro and much easier to see which way round to put it in! I'd use USB-C if it were commonly available for the charger parts.

    2021-06-26 10.48.17.jpg

    Below - I drilled a 2mm hole so you can see the charging status LED. Red = charging, green = full.

    2021-06-26 10.48.37.jpg

    I've just powered it up and it shows P7 in the control panel software, and I'm plotting the voltage over time - we'll which lasts longer, the AB, the tablet, or the 18R2 (powered by a bit lithium powerbank)!

    In all seriousness - I'll pop back out shortly and plug the tablet and powerbank on charge so they last the test :)

    Easy mod and costs very little.

    I'm going to attach one of these when it arrives:


    Though it won't be needed in all reality. The 18650s should last a loooong time. I've got better quality ones on order.

    This is the charger : (well, mine is very slightly different - a single dual colour LED, not two seperate ones, and mini, not micro usb)


    It will happily still run with three AA batteries installed too, as a backup. Prob not ideal, but it works. Very similar voltages.
    Last edited: Jun 26, 2021
    Pyro Pete and hofnerite like this.
  2. Is this a known issue? I've run a few shows and an MLE comp with one running on AA's and never had an problem.
  3. Dodgey

    Dodgey Pro Firer/Crew

    Don't know tbh - but the guy I bought my other AB off fitted the SLA as his ran flat part way through a show.

    Besides, I just don't like running on low capacity batteries.
  4. hofnerite

    hofnerite UKFR Stash Photo 2018 Winner! Supports UKFR

    Yeah they eat batteries big time. I always use Energiser lithium but even they will only last a few hours.
    A LiPo upgrade is coming soon for the AB apparently.
  5. Good to know, I'll have to bear that in mind! Thanks.
  6. elmo

    elmo Pro Firer/Crew

    Waiting ..........................
    hofnerite likes this.
  7. Dodgey

    Dodgey Pro Firer/Crew

    Quick test - started at P6 and ran at that for 45 mins, then dropped to P5 and that ran for an unknown time. Just got back at 20:45 (7 hours later) and was at P3 - still usable). Pressed the test button to run an audio track here and there too to emulate a "load".

    Works great, and most importantly means I can chill when the band plays "just one more song", and then 40 minute delay for other reasons (not an unusual event!)

    Ignore the P7 - I had the charger plugged in - doh! :)

    Taken at 13:25 at the moment it dropped to P6 (I unplugged the charger)


    Taken at 20:45 (I powered down the tablet whilst out, hence no looooong graph)

    hofnerite likes this.
  8. Lithium ion battery's have an issue when they run too low chargers won't reckonize the cells it happens a lot with power tools and the like you have to jump start a bad battery with a good one so two lengths of single core wire with say penny washers put into + - terminals to create circuit and left for 15min then pop bad battery back in to charge and 9 times out of ten it comes back to life hope that helps if your at a loss all the best guys.
  9. Dodgey

    Dodgey Pro Firer/Crew

    Same issue with Lipo cells.

    The charger I used has battery connections, input, and output. It shuts off the output at 2.6v so you can't over discharge a Lion (Lipo would not like it).

    Going by my quick test you'd need to leave it on overnight for that to even kick in.
  10. pyroplayer

    pyroplayer Pro Firer/Crew Supports UKFR

    Always fresh AA for every show here, you can also safely arm the system and then turn on the audio box on last minute before firing. I also believe that if the show is running, your batteries die, you can swap them and turn back on without stopping the show and it'll catch up.

    I'm planning to make a custom mains powered 1U racked AudioBox soon. 99% of our musical shows go out with our audio racks with amps etc anyway, make sense to have it all built-in and powered. Our 18R2 already have locking mains powered jacks retrofitted, again for the big shows where the client is running late, it is far less stressful sitting on arm for an unknown amount of time when you're not relying on batteries.
  11. Dodgey

    Dodgey Pro Firer/Crew

    I've now swapped out the 1A Lion chargers for 3 Amp chargers - faster charging, and a dedicated two colour LED which makes mounting easier.


    I also have locking jacks fittet to our 18R2s, powered by large Anker batteriy packs - they just run and run.

    I have discovered, and be warned about this, something in the process of installing external power to the Audiobox can trigger/cause boot up issues for the USB.

    I've got one that will only play the test audio (green LED) when powered up the second time. 1st Power on and it does not initialise properly, flip off and on and then it does, always. It's very odd. Checked everything, thoroughly. At one stage one AB was almost always refusing to initialise the USB properly. I re synced it with the 18R2 and then it behaved perfectly. Then after a while slipped back into always needing a power toggle to work again. Recently it has started behaving perfectly again...

    Checked all soldering. Even snipped wires and 100% eliminated external power pack and batt checker - put AAs back in, same problem.
    Multiple USB keys, multiple audio files.

    Can't for the life of me understand why. Zach at Cobra says it's a known issue when customers power their ABs externally, sometimes. But he doesn't know why. He suggested maybe under voltage or over voltage but I just can't see it

    3 x AA = 4.5v
    3 x AA rechargable = 3.6v
    X x Lion in parallel = 3.7v empty, 4.2v full.

    So you are always within spec.

    I now have three ABs
    1 x Old Hardware A, used to be powered by 6v SLA stepped down to 4v. Behaved perfectly for a couple of years, then started needing a power toggle to work (recently) - remember this for below:

    1 x 1 year old unused AB ver B. Was perfect. Installed Lions, then started to need a power toggle to initialise. Now back to not needing one!

    2 x Brand new AB (Cobra warranty replacement for the 1st in this list) - converted to Lions. No issues at all.

    At one stage I wondered it if was soldering the power cables whilst still attached to the Cobra - should not be a problem - just heat. But static maybe? I now unplug the power plug on the PCB when doing and soldering. But now, bearing in mind the above, I'm wondering if something changed after a firmware update. My 1st AB was rock solid and only started misbehaving recently - 1st use in a year due to lockdowns, so 1st use on it's latest current firmware.