USB charging 9v batteries

[JoeEvans]

I bought one of those rechargeable 9V batteries the other day that have a USB C socket right there in the battery, so you can just plug it in without needing a charger. Great item in itself, but it occurred to me that you could wire it to a socket on the back of a bass, so that you wouldn't need to open the back and take the battery out to charge it. Has anyone done this?

[thebrig]

1 hour ago, JoeEvans said:

I bought one of those rechargeable 9V batteries the other day that have a USB C socket right there in the battery, so you can just plug it in without needing a charger. Great item in itself, but it occurred to me that you could wire it to a socket on the back of a bass, so that you wouldn't need to open the back and take the battery out to charge it. Has anyone done this?

Don't tell everyone, Patent your idea.🤐

[Beedster]

John East had a similar charging system on the P-Retro (not USB, 1/4 jack, but similar principle) 👍

[TimR]

KUOQIY 6 PCS USB Type C Soldering Panel Mount Female Cable, 3A 2 Wire Type C Female USB-C with LED light, 2 Pin Type-C Female Power Jack with 150mm 24 AWG Wire, with Dust Covers and Nuts https://amzn.eu/d/7pBnEM5

 

 

[Downunderwonder]

8 minutes ago, TimR said:

KUOQIY 6 PCS USB Type C Soldering Panel Mount Female Cable, 3A 2 Wire Type C Female USB-C with LED light, 2 Pin Type-C Female Power Jack with 150mm 24 AWG Wire, with Dust Covers and Nuts https://amzn.eu/d/7pBnEM5

 

 

No cigar.

 

OP needs a female USB or USB-C panel mount with male USB-C plug on cable to go to the battery on the other side of the panel.

 

 

[TimR]

24 minutes ago, Downunderwonder said:

No cigar.

 

OP needs a female USB or USB-C panel mount with male USB-C plug on cable to go to the battery on the other side of the panel.

 

 

Yep. But you wont be able to buy a ready made lead like that. He now just needs an inline USB C plug and solder it on to the two wires. The difficult part (panel mount) is done there for him. 

[Aidan63]

I'd advise seeing how the battery works before modifying the instrument - I bought a couple of these PUJIMAX branded batteries earlier this year and I have found they aren't really anywhere like 1200mAh they state on the label (which in itself is a 'fake' of the old FujiMax one) and don't last very long, because they have the charging circuit board inside so they have less actual cells than the old 600mAh batteries I have and don't last as long as the old ones do even after a few years use. I also found that like many simple lithium cell devices you can't use them whilst being charged, so you might not be able to charge the battery in the device whilst the battery is plugged in

[TimR]

21 minutes ago, Aidan63 said:

I'd advise seeing how the battery works before modifying the instrument - I bought a couple of these PUJIMAX branded batteries earlier this year and I have found they aren't really anywhere like 1200mAh they state on the label (which in itself is a 'fake' of the old FujiMax one) and don't last very long, because they have the charging circuit board inside so they have less actual cells than the old 600mAh batteries I have and don't last as long as the old ones do even after a few years use. I also found that like many simple lithium cell devices you can't use them whilst being charged, so you might not be able to charge the battery in the device whilst the battery is plugged in

 

The 9v on an active bass should be out of circuit when its lead is unplugged. 

 

Active bass batteries last months. 

 

Although I'd agree, modifying the bass to fit a plug seems a bit OTT. Why not just buy two batteries and modify the bass to have a quick release compartment for the battery. It's not like you'll be charging it every day/week/month. 

[Bigguy2017]

Just mount one of these on the rear cover plate - easy enough to drill + file the wee slot for USB-C

 

JSADZKJ USB 2.0 Tyep C Panel Mount Cable 90 Degree Angle USB C Male to Female Extension CableUSB 2.0 Type C Cable with Panel Mount Screw for Laptop, Tablet, Mobile Phone 1ft/30cm: Amazon.co.uk: Computers & Accessories

 

 

[tauzero]

I've bought a couple of these, but to use in Variaxes which take 6xAA batteries when on open mic nights, so high consumption but short duration. I haven't yet assessed how long they last for.

 

It would be a bit tricky adding a charging cable when there's a separate battery compartment as there wouldn't be room for the plug in the battery compartment, or for the socket in the lid, and generally the hole between control cavity and battery compartment would be too small to pass the plug through so that solution is also precluded. Single compartments (eg later Warwicks) would be more feasible. But if the battery lasts a few months, it's not exactly onerous to take it out for a recharge now and again.

[Downunderwonder]

12 hours ago, Bigguy2017 said:

Just mount one of these on the rear cover plate - easy enough to drill + file the wee slot for USB-C

 

JSADZKJ USB 2.0 Tyep C Panel Mount Cable 90 Degree Angle USB C Male to Female Extension CableUSB 2.0 Type C Cable with Panel Mount Screw for Laptop, Tablet, Mobile Phone 1ft/30cm: Amazon.co.uk: Computers & Accessories

 

 

Cigar!

[lemmywinks]

78p on AliExpress:

 

https://www.aliexpress.com/item/1005003437763396.html

[lemmywinks]

Right angle option here:

https://www.aliexpress.com/item/1005001762409569.html

Edited October 18, 2024 by lemmywinks

[lemmywinks]

Thinking about this isn't it about time manufacturers give us modern features on basses? A decent internal battery and a little discreet screen on the upper edge showing the remaining battery level with a built in tuner wouldn't go amiss.

 

 

[JoeEvans]

30 minutes ago, lemmywinks said:

Thinking about this isn't it about time manufacturers give us modern features on basses? A decent internal battery and a little discreet screen on the upper edge showing the remaining battery level with a built in tuner wouldn't go amiss.

 

 

I would like that. I know 9v batteries last for ages and aren't much trouble to change, but it's annoying to have a big gig coming up and to be wondering about the state of the battery. I'd like to have either an external charging port, so I can just plug it in while it's sat on a stand in the corner; a battery charge indicator; or phantom power, so I can just use a preamp with phantom power and be done with it.

Ideally the system that I gather Chapman Sticks have, or some of them anyway, where they run active if they have phantom power, and passive if not.

Edited October 18, 2024 by JoeEvans

[goingdownslow]

I bought some of the Pujimax ones after reading this thread. They didn't last 2 months in my Thumb Bass, used in the house for about an hour or so a week. The spare that was fully charged at the same time was also flat. I put back the Duracell that was installed in June 2019 ( I always write the date on) and that still worked.

[Stub Mandrel]

I got four similar ones. Far too noisy in my Sire.

[Cliff Edge]

Rechargeable PP3 batteries don’t deliver a full 9volts which may not suit some instruments.  

[goingdownslow]

25 minutes ago, Cliff Edge said:

Rechargeable PP3 batteries don’t deliver a full 9volts which may not suit some instruments.  

Some years back rechargeable PP3s were only 7.2 volts, then they became 8.4 volts and then 9.6 volt. Each time the capacity becoming less as they were trying to cram more 1.2v cells into the same size battery.
These Lithium-ion batteries do measure 9+ volts but I doubt the 1200mA.

Edited Sunday at 11:45 by goingdownslow

[Cliff Edge]

32 minutes ago, goingdownslow said:

Some years back rechargeable PP3s were only 7.2 volts, then they became 8.4 volts and then 9.6 volt. Each time the capacity becoming less as they were trying to cram more 1.2v cells into the same size battery.
These Lithium-ion batteries do measure 9+ volts but I doubt the 1200mA.

Good to know, thanks. 

[binky_bass]

Warwick have been doing this for some years. Hard to spot, but you can see the USB in on the back of the control panel.

 

[PinkMohawk]

Something like mounting a charging port on the bass really requires something like a pouch battery or similar, 9v rechargeable, as mentioned above, aren't really fit for the purpose. Fishman does something similar, though I don't know if they have a version for sale that only has the battery and port that you could use to retrofit a bass.

[itu]

EBS had a built in 9 V Phantom in their preamps. Just connect your bass with a stereo (TRS) cable.

[Happy Jack]

Fit a 3-pin plug and go straight to mains.

 

Just make sure that you use a 5A fuse and proper shielding ...

 

[Jean-Luc Pickguard]

My US Fender acoustasonic jazzmaster guitar has fishman electronics with a micro usb on the jack plate with an LED to indicate the charge level. Obviously USB-C would have been much better, and mounting the socket anywhere but the jackplate would make it easier to charge.