Battery power supply for small pedal board

[cooder]

Something from left field: I wanted to make me a small portable board with rechargeable battery powered. Quick grab and go, good for jam sessions and also to quickly throw some pedals on there for testing etc.
I have done one in the past similar using 18650 batteries, and that worked well too. However, I found swapping batteries and having enough grunt important in this, so I bought a charger and batteries for 18V powered drills (same as I use in workshop anyway) and gutted the charging station to turn it into battery holder and put a buck converter inside to regulate voltage down to 9.4 V and keep it constant there.
I stuck two little voltmeters in, the blue one shows battery voltage, red one show outgoing voltage to pedals. So I always can see if voltage in battery drops and quickly stick replacement in when needed. Should run quite a bit though, the smaller battery is rated at 2.5 Ah and the bigger one at 4 Ah.
Made a wee wooden board that holds up to 7 x 125B boxes and recess for the power supply. Board is made from NZ native red beech.
Here we go, a bit picture heavy to show the process:

Cutting out holes for 9V jacks and voltage displays. Dremel works great for this, if you try to drill plastic with a normal spiral bit it often cracks, ask me how I know.

Buck converter and voltage displays installed.

The wooden pedal board:

 

[jimilee]

Something from left field: I wanted to make me a small portable board with rechargeable battery powered. Quick grab and go, good for jam sessions and also to quickly throw some pedals on there for testing etc.
I have done one in the past similar using 18650 batteries, and that worked well too. However, I found swapping batteries and having enough grunt important in this, so I bought a charger and batteries for 18V powered drills (same as I use in workshop anyway) and gutted the charging station to turn it into battery holder and put a buck converter inside to regulate voltage down to 9.4 V and keep it constant there.
I stuck two little voltmeters in, the blue one shows battery voltage, red one show outgoing voltage to pedals. So I always can see if voltage in battery drops and quickly stick replacement in when needed. Should run quite a bit though, the smaller battery is rated at 2.5 Ah and the bigger one at 4 Ah.
Made a wee wooden board that holds up to 7 x 125B boxes and recess for the power supply. Board is made from NZ native red beech.
Here we go, a bit picture heavy to show the process:

Cutting out holes for 9V jacks and voltage displays. Dremel works great for this, if you try to drill plastic with a normal spiral bit it often cracks, ask me how I know.

Buck converter and voltage displays installed.

The wooden pedal board:

Oh hell yeah, that is DI fuckin Y right there. I love it.

 

[PunchySunshine]

Something from left field: I wanted to make me a small portable board with rechargeable battery powered. Quick grab and go, good for jam sessions and also to quickly throw some pedals on there for testing etc.
I have done one in the past similar using 18650 batteries, and that worked well too. However, I found swapping batteries and having enough grunt important in this, so I bought a charger and batteries for 18V powered drills (same as I use in workshop anyway) and gutted the charging station to turn it into battery holder and put a buck converter inside to regulate voltage down to 9.4 V and keep it constant there.
I stuck two little voltmeters in, the blue one shows battery voltage, red one show outgoing voltage to pedals. So I always can see if voltage in battery drops and quickly stick replacement in when needed. Should run quite a bit though, the smaller battery is rated at 2.5 Ah and the bigger one at 4 Ah.
Made a wee wooden board that holds up to 7 x 125B boxes and recess for the power supply. Board is made from NZ native red beech.
Here we go, a bit picture heavy to show the process:

Cutting out holes for 9V jacks and voltage displays. Dremel works great for this, if you try to drill plastic with a normal spiral bit it often cracks, ask me how I know.

Buck converter and voltage displays installed.

The wooden pedal board:

Clean as a whistle! Well done!

 

[falco_femoralis]

Damn that is a clean board

 

[Harry Klippton]

Hey @cooder did you make your own daisy chain too? Where'd ya get the plugs? Also where'd you get the volt meters?

 

[Paradox916]

That’s pretty cool…. Now make it isolated

 

[cooder]

Hey @cooder did you make your own daisy chain too? Where'd ya get the plugs? Also where'd you get the volt meters?

Yep haha I did make the daisy chain myself as well. I don't like the premade daisy chains with way too mych cable floating around. I wonder if anyone out there has really good ways, other alternatives to make custom length daisy chains with good right angle plugs?
What I used at this stage is the standard garden variety plug from Tayda
https://www.taydaelectronics.com/hardware-tools/dc-power/dc-power-plug-2-1mm-x-5-5mm-x-9-5mm.html
then cut the end off, dremel a side hole into it, fiddle wires through, solder on, push back on (you can screw turn it at that point obviously, once it's all hooked up and tested I fill it with epoxy to make it bomb proof.

If anyone has better right angle connectors let me know. I don't like the right angle connectors that tayda has, I think above works better for me.

The voltmeters are from evilbay
https://www.ebay.com/itm/2772562329...+azsefbSra+12JB/mqBMMwrQ==|tkp:Bk9SR-ryhtveZg

 

[Paradox916]

I’m curious with those batteries, is it any more noisy than a similar daisy chain

 

[cooder]

I’m curious with those batteries, is it any more noisy than a similar daisy chain

I couldn't detect any noise so far. Haven't used it at high volume band settings yet though.

 

[fopoman]

Something from left field: I wanted to make me a small portable board with rechargeable battery powered. Quick grab and go, good for jam sessions and also to quickly throw some pedals on there for testing etc.
I have done one in the past similar using 18650 batteries, and that worked well too. However, I found swapping batteries and having enough grunt important in this, so I bought a charger and batteries for 18V powered drills (same as I use in workshop anyway) and gutted the charging station to turn it into battery holder and put a buck converter inside to regulate voltage down to 9.4 V and keep it constant there.
I stuck two little voltmeters in, the blue one shows battery voltage, red one show outgoing voltage to pedals. So I always can see if voltage in battery drops and quickly stick replacement in when needed. Should run quite a bit though, the smaller battery is rated at 2.5 Ah and the bigger one at 4 Ah.
Made a wee wooden board that holds up to 7 x 125B boxes and recess for the power supply. Board is made from NZ native red beech.
Here we go, a bit picture heavy to show the process:

Cutting out holes for 9V jacks and voltage displays. Dremel works great for this, if you try to drill plastic with a normal spiral bit it often cracks, ask me how I know.

Buck converter and voltage displays installed.

The wooden pedal board:

Amazing build!

 

[MattG]

That is awesome! At a glance, that battery pack kind of looks like the Cry Baby Mini I have on my board.

I'm curious about your 18650-based scheme too, as I always wanted to do something like that. My understanding is that safe lithium ion charging isn't too terribly hard, but ideal lithium ion charging needs some degree of smarts. And I'm also not clear on what it takes to make a circuit where the batteries can provide power and be charged at the same time. I basically want the equivalent of a datacenter-grade UPS (uninterruptable power supply) for pedals. I want to be able to plug it in, like I normally do, and it will charge the batteries. But if the power flickers or someone accidentally pulls/steps on my AC power cable (it's happened), then the board runs off battery power. And I have the option to run straight from battery if there's no AC handy.

I'm also curious how these premium pedal power supplies (e.g. Cioks, Truetone, Voodoo Lab) do isolation in such a small package. The only "easy" way I could think of is using a transformer with as many secondaries as you need outputs. But if you're starting with DC, i.e. coming from a battery, then to get isolation you have to invert to AC so you can use a transformer, then re-rectify and regulate. That adds a lot of inefficiency and size, and just feels wrong for something battery-powered. There must be another way to do isolation in the DC domain, i.e. without a transformer?

Anyway, thanks for sharing, that's really inspiring!