Battery-box pedal power - 9v 7.2v ??

guitarcookie1guitarcookie1 Frets: 222
Inspired by another thread on here, and for the princely sum of £9.80, I've made two battery-box power supplies for my mini board - one takes 6 x standard AA batteries (6 x 1.5v = 9v) and the other 8 x rechargeable AA batteries (8 x 1.2v = 9v).

The standard box works fine but when I tried the rechargeable one nothing, no power to either pedal. To eliminate the rechargeable batteries being the issue I put six of them in the other box and this also worked fine - this surprised me as I didn't think there'd be enough volts to power the pedals, only 7.2v?

Would I be damaging the pedals by running them on a lower voltage or will it just mean that the power supply won't last as long between charges?

The items on the board are just a Bogner Ecstasy Blue and a Line 6 G30 receiver.
0reaction image LOL 0reaction image Wow! 0reaction image Wisdom · Share on Facebook Share on Twitter

Comments

  • John_AJohn_A Frets: 1833
    Have you actually measured the voltage with a multi-meter?  My guess is that they would probably work at anywhere between 7-12 volts, with 9 obviously being optimal.  I suspect the wiring in the 8 battery power box is wrong
    Do me a favour and like this:

    https://www.facebook.com/MarkedCoversBand
    0reaction image LOL 0reaction image Wow! 0reaction image Wisdom · Share on Facebook Share on Twitter
  • ICBMICBM Frets: 33969
    Sounds like a wiring fault in the 8 box. The only way it wouldn't work otherwise is that the two units both have protection circuitry so sensitive to over-voltage that they shut down at 9.6V, which is highly unlikely.

    The Line6 will almost certainly be fine at 7.2V and probably run slightly cooler - it's likely to have a regulator which drops it straight to 5V anyway. Not sure about the Bogner, but if it works fine and doesn't sound different (eg lower headroom) then it should be no worse than running at 9V.
    "Take these three items, some WD-40, a vise grip, and a roll of duct tape. Any man worth his salt can fix almost any problem with this stuff alone."
    0reaction image LOL 0reaction image Wow! 0reaction image Wisdom · Share on Facebook Share on Twitter
  • steamabacussteamabacus Frets: 931
    edited October 12
    I think it was my post that you saw.

    I had a similar problem with my rechargeable version - zero output, batteries tested fine.

    The culprit was the Maplin brand rechargeable AA batteries - the metal 'nipple' at the positive end was too short to pass through the small gap in the plastic wall inside the battery box where the final positive terminal connects to the output. Have a good look at your batteries and the inside of the box and check that the final one is making contact.

    Another brand of rechargeable AA and normal alkaline AA batteries were fine. Also the maplin batteries made contact at the final negative end and at all the internal bridging connectors between individual batteries - it was only the final contact at the positive end that was a problem.

    [edit] Also, at full charge I noticed I was getting well over 1.2V per battery - I was measuring around 10.5V if I remember (still ok to power (V pedals). I would guess that 6 freshly charged rechargeables would be CLOSE to a full 9V but would probably drop off quite quickly.
                                                                                                                                                   My 'Guitar diaries' on BandCamp
                                                                                                                                                            My Soundcloud stream

    0reaction image LOL 0reaction image Wow! 0reaction image Wisdom · Share on Facebook Share on Twitter
  • John_A said:
    Have you actually measured the voltage with a multi-meter?  My guess is that they would probably work at anywhere between 7-12 volts, with 9 obviously being optimal.  I suspect the wiring in the 8 battery power box is wrong
    The 6 x rechargeables look to be 8.9v & 6 x standard batteries 9.4v (at least these are the figures the multimeter settles on and slowly counts down from there).

    ICBM said:
    Sounds like a wiring fault in the 8 box. The only way it wouldn't work otherwise is that the two units both have protection circuitry so sensitive to over-voltage that they shut down at 9.6V, which is highly unlikely.

    The Line6 will almost certainly be fine at 7.2V and probably run slightly cooler - it's likely to have a regulator which drops it straight to 5V anyway. Not sure about the Bogner, but if it works fine and doesn't sound different (eg lower headroom) then it should be no worse than running at 9V.
    Thank you, that's good to know, thank you.

    I think the 8 box is definitely faulty somewhere inside as there's no output with either standard or rechargeable batteries.

    I think it was my post that you saw.

    I had a similar problem with my rechargeable version - zero output, batteries tested fine.

    The culprit was the Maplin brand rechargeable AA batteries - the metal 'nipple' at the positive end was too short to pass through the small gap in the plastic wall inside the battery box where the final positive terminal connects to the output. Have a good look at your batteries and the inside of the box and check that the final one is making contact.

    Another brand of rechargeable AA and normal alkaline AA batteries were fine. Also the maplin batteries made contact at the final negative end and at all the internal bridging connectors between individual batteries - it was only the final contact at the positive end that was a problem.

    [edit] Also, at full charge I noticed I was getting well over 1.2V per battery - I was measuring around 10.5V if I remember (still ok to power (V pedals). I would guess that 6 freshly charged rechargeables would be CLOSE to a full 9V but would probably drop off quite quickly.
    These are Energisers and are quite a tight fit in both boxes.

    I'll have a good play with the 6 box over the weekend and see how long they last..

    0reaction image LOL 0reaction image Wow! 0reaction image Wisdom · Share on Facebook Share on Twitter
  • steamabacussteamabacus Frets: 931
    These are Energisers and are quite a tight fit in both boxes.


    But does the final positive connection pass THROUGH the space in the plastic wall and touch the metal contact BEHIND the wall?
                                                                                                                                                   My 'Guitar diaries' on BandCamp
                                                                                                                                                            My Soundcloud stream

    0reaction image LOL 0reaction image Wow! 0reaction image Wisdom · Share on Facebook Share on Twitter
  • These are Energisers and are quite a tight fit in both boxes.


    But does the final positive connection pass THROUGH the space in the plastic wall and touch the metal contact BEHIND the wall?
    Yes it does, the problem cell was position five. A bit of bending of the positive contact and we're in business, thank you :)


    0reaction image LOL 0reaction image Wow! 0reaction image Wisdom · Share on Facebook Share on Twitter
  • ICBMICBM Frets: 33969

    The culprit was the Maplin brand rechargeable AA batteries - the metal 'nipple' at the positive end was too short to pass through the small gap in the plastic wall inside the battery box where the final positive terminal connects to the output.
    I've got some of those and had the same problem with my older Apple wireless mouse - I fixed it by simply adding a small dome of solder to each of the batteries.
    "Take these three items, some WD-40, a vise grip, and a roll of duct tape. Any man worth his salt can fix almost any problem with this stuff alone."
    0reaction image LOL 0reaction image Wow! 0reaction image Wisdom · Share on Facebook Share on Twitter
  • steamabacussteamabacus Frets: 931
    They say a picture's worth a thousand words. Here's the issue that had me confused for a couple of days, hopefully this will save someone some grief if it happens to you.


                                                                                                                                                   My 'Guitar diaries' on BandCamp
                                                                                                                                                            My Soundcloud stream

    0reaction image LOL 0reaction image Wow! 0reaction image Wisdom · Share on Facebook Share on Twitter
  • steamabacussteamabacus Frets: 931
    edited October 12
    These are Energisers and are quite a tight fit in both boxes.


    But does the final positive connection pass THROUGH the space in the plastic wall and touch the metal contact BEHIND the wall?
    Yes it does, the problem cell was position five. A bit of bending of the positive contact and we're in business, thank you


    Glad you got to the bottom of it.

    When I made mine (I also made a 6x alkaline and 8x rechargeable) they both worked fine. Then I took out the rechargeables to recharge them (4x Maplin, 4 x Vanson) before a gig. When I put them back in - no power!. Thankfully, I had the other box and used that.

    The day after the gig I checked over the rechargeable box with a multimeter and all the connections were fine. Of course, I'd put the batteries back in a different order after recharging!
                                                                                                                                                   My 'Guitar diaries' on BandCamp
                                                                                                                                                            My Soundcloud stream

    0reaction image LOL 0reaction image Wow! 0reaction image Wisdom · Share on Facebook Share on Twitter
  • steamabacussteamabacus Frets: 931
    edited October 12
    One other thing about these cheap battery boxes (I got mine from eBay).

    Beware the battery polarity markings moulded into the individual cells - if you look at the second photo down in the image above, you will see that the third cell down has the battery polarity marked the wrong way round (one of the reasons why I 'idiot-proofed' mine with the clear silver Sharpie '+' markings for the positive end of each cell). One of my boxes had just two of the middle cells incorrectly marked. If you look at the connections, though, it is obvious which end is which - the negative ends are sprung)
                                                                                                                                                   My 'Guitar diaries' on BandCamp
                                                                                                                                                            My Soundcloud stream

    0reaction image LOL 0reaction image Wow! 0reaction image Wisdom · Share on Facebook Share on Twitter
Sign In or Register to comment.