USB 9V rechargeable battery

[douglasfan1]

I've just tried 4 USB 9V rechargeable batteries individually for acoustic preamp (Highlander IP-2) and a blender preamp (L.R.Baggs Mixpro), both got the unwanted noise which disappear when I use normal 9V battery.

Is that the normal result when using rechargeable 9V battery in audio gear?

[AeroUSA]

Originally Posted by douglasfan1

I've just tried 4 USB 9V rechargeable batteries individually for acoustic preamp (Highlander IP-2) and a blender preamp (L.R.Baggs Mixpro), both got the unwanted noise which disappear when I use normal 9V battery.

Is that the normal result when using rechargeable 9V battery in audio gear?

Yes I would avoid them.

[Cuki79]

Originally Posted by douglasfan1

I've just tried 4 USB 9V rechargeable batteries individually for acoustic preamp (Highlander IP-2) and a blender preamp (L.R.Baggs Mixpro), both got the unwanted noise which disappear when I use normal 9V battery.

Is that the normal result when using rechargeable 9V battery in audio gear?

Those use a DC-DC voltage converter than can be noisy if not properly filtered.

my 2 cents,
CUki

[lkingston]

NiMH 9v rechargeables come in three voltages: 7.2, 8.4, and 9.6. Often an 8.4 or 9.6 volt battery will work were the stock 7.2 volt one doesn’t have enough voltage.

[Cuki79]

Originally Posted by lkingston

NiMH 9v rechargeables come in three voltages: 7.2, 8.4, and 9.6. Often an 8.4 or 9.6 volt battery will work were the stock 7.2 volt one doesn’t have enough voltage.

I think he was refering to something like that

[varmonter]

Maybe one of the EE here could
explain how a battery could impart
noise. In layman's terms.

[douglasfan1]

Originally Posted by Cuki79

I think he was refering to something like that

Exactly, is that work or all those batteries are not function properly in audio equipment?

[shufflebeat]

Originally Posted by douglasfan1

Is that the normal result when using rechargeable 9V battery in audio gear?

Just to re-clarify - we're talking about USB rechargeables here, not just any r/c which, in my experience, are no different to single use. Is this correct?

[lkingston]

Originally Posted by shufflebeat

Just to re-clarify - we're talking about USB rechargeables here, not just any r/c which, in my experience, are no different to single use. Is this correct?

I didn’t know there were Lithium-ion rechargeable batteries with USB ports for recharging. It looks like a product I would use...unless it makes noise...

What is the actual output voltage of these batteries?

I know that I don’t get any added noise with my NiMH batteries. I use the 9.6 variety in everything but Boss pedals (which don’t work with the extra .6 volts). 8.4v NiMH batteries work fine in Boss pedals.

For anyone who might be curious, a standard 9v Alkaline battery is made up of 6 1.5v cells wired in series. NiMH cells are only 1.2v, so when 6 of them are wired in series (as in a standard 9v battery form factor) the output voltage is 7.2 volts (6 x 1.2v). 8.4 volt rechargeables cram an extra 1.2 cell into the same case bringing the output voltage up 1.2v which results in an 6.4 voltage. 9.6 volt rechargeables stick 8 1.2v cells in the same case, bringing the voltage up to 9.6 volts.

These are all initial voltages with a full charge. These voltages go down gradually as the battery depletes, making it easy to monitor their power with a built in battery meter.

A few years ago, I tried a couple of LiON batteries in some audio gear. What I liked was that they gave a full 9 volts and lasted a decent amount of time at that voltage.

What I didn’t like is that the metering on the gear would say full right up until the point that they suddenly died. I was doing video work at the time, and I would go into a take having just looked at three bars of battery, only to have it die mid take. That is why I stopped using them. They worked well other than that.

[keith.rogers]

I've used Talentcell Lion battery packs for cameras and field recorders and they've been noise free. If your gear has a jack for external power, I'd look for something like that. The ones I used were 12v and 12/5v models, but I see they have at least one 9v model. There may be other brands and sizes, of course. Just one datapoint...

https://www.amazon.com/dp/B01337QXMA...pa_dk_detail_2

P.S. I found the LED power (remaining) indicators good enough for field use, though I always had a backup and switch things out before "the lights went out." (My field recorders had voltage indicators, too.)

[phcorrigan]

Originally Posted by keith.rogers

I've used Talentcell Lion battery packs for cameras and field recorders and they've been noise free.

I use a similar 12V battery for my ToneDexter. When I got my Gretsch electric and started building my pedalboard, I installed a 12v-9v converter on the bottom of the board so I could use the same battery (or a 12v power supply) for my pedals.

This is the converter: https://www.amazon.com/SMAKN%C2%AE-C...1688230&sr=8-1

With connectors, I spent less than $10 for the converter.

[phcorrigan]

Originally Posted by keith.rogers

I've used Talentcell Lion battery packs for cameras and field recorders and they've been noise free. If your gear has a jack for external power, I'd look for something like that. The ones I used were 12v and 12/5v models, but I see they have at least one 9v model. There may be other brands and sizes, of course. Just one datapoint...

https://www.amazon.com/dp/B01337QXMA...pa_dk_detail_2

P.S. I found the LED power (remaining) indicators good enough for field use, though I always had a backup and switch things out before "the lights went out." (My field recorders had voltage indicators, too.)

Be careful if you buy this battery. The 9v connection is center-positive, and most guitar pedals require center-negative, so you'll need to build or buy a crossover cable.

[douglasfan1]

I think the easiest way is to use back the normal standard 9v battery then cause they last quite a long time actually. I just hate to un-attach the battery as the attachment thing looks like easy to be damaged. Anyway, thank you for all the response.

[lkingston]

Originally Posted by douglasfan1

I think the easiest way is to use back the normal standard 9v battery then cause they last quite a long time actually. I just hate to un-attach the battery as the attachment thing looks like easy to be damaged. Anyway, thank you for all the response.

I think the issue must be in the USB recharging circuit. Regular rechargables would probably work fine if they had a separate charger instead of the USB port.

[dnf777]

My understanding from other Li-ion applications is that they all have an internal circuit to monitor and prevent overcharging, as where ni-cad andvothers do not. Perhaps this generates noise in susceptible situations. Maybe simply some shielding foil in the battery compartment would fix it?