looking for small 5v to 2.4v-3v regulator PCB with connection to 2x AA rechargeable batteries

[radiance32]

Hi,

I'm looking for a small PCB that accepts 5V (coming from a USB port, only used as a power supply),
and that provides 2.4v to 3.0v (the equiv of 2 alkaline or NI-MH rechargeable AA batteries)
to the system, and connects to a pair of rechargeable NI-MH batteries,
that it uses for power if the USB 5V power is not connected/available.
It should also recharge the batteries up to %100 when it is connected to the 5V USB power supply.
The current drawn by the device at the 2.4 to 3.0 voltage is approx ~100mah to ~250mah.

I'd like a ready-made, drop-in solution (not a kit that i need to solder together myself),
small size PCB board that does this. The board needs to be tiny, as small as possible,
I'm hoping for something that's just 25x20mm or similar, just the smallest possible...

Does anyone know of a suitable board like this that I can purchase online? (I need 14 of them in total)
I don't have much electronics skills, so if you have any questions, please be verbose,
however, I'm moderately proficient at soldering.

If anyone could drop a reply with a name and/or link for a suitable item like this,
I'd really appreciate it

Thanks,
Terrence

 

[RayRay1132]

I could try to design a pcb that does that for you. How fast does it have to charge the battery. (Current Requirements)?

 

[radiance32]

I could try to design a pcb that does that for you. How fast does it have to charge the battery. (Current Requirements)?

Hi,

While I appreciate your offer, I just need to buy some ready-made boards, something you can buy off an electronics resaler for a couple of dollars, I don't really have the time to start designing PCBs, ordering components, soldering them on etc... while there are perfectly fine solultions already out there that I can buy, I just need to know which one to buy out of the many on offer...
No point in re-inventing the wheel...

So if anyone knows about a good read-made solution, tiny PCB with regulator IC on it etc... it would be great if you could let me know in this thread...

Thanks!,
Terrence

 

[Visitor]

Could you use a "USB power bank" board and an appropriate sized LiIon battery? This type of module is probably easier to find.

 

[gophert]

I have a ready made solution, I just have to solder a single resistor to it to set the output voltage.
you can add a fuse or just a jumper wire.
Boards are 25mm x 19mm.
They are designed for this regulator capable of 1.5A with short circuit protection and needs a 5 to 14vdc input.
**broken link removed**

One or two 0805 smd resistor pads are for setting the output voltage. The second resistor is in parallel to fine tune output. They have incredible voltage compliance across a wide load range (0.01v). The large holes on one end are all connected to ground. Each end of the board has the same input, ground and output plus a control pin (enable) but that does not need to be connected.

they are switch mode power supplies so they generate very little heat. Send a PM, if you want a set of 20 and and offer, boards only, no regulator.

 

[Visitor]

The Murata module is zero stock at Digikey, but Mouser has over a thousand in stock.

 

[radiance32]

I have a ready made solution, I just have to solder a single resistor to it to set the output voltage.
you can add a fuse or just a jumper wire.
Boards are 25mm x 19mm.
They are designed for this regulator capable of 1.5A with short circuit protection and needs a 5 to 14vdc input.
**broken link removed**

One or two 0805 smd resistor pads are for setting the output voltage. The second resistor is in parallel to fine tune output. They have incredible voltage compliance across a wide load range (0.01v). The large holes on one end are all connected to ground. Each end of the board has the same input, ground and output plus a control pin (enable) but that does not need to be connected.

they are switch mode power supplies so they generate very little heat. Send a PM, if you want a set of 20 and and offer, boards only, no regulator.

Thanks, gophert,
but I don't have time to look for all the components and solder them all on,
and, you're board is too high (the components are too large/high), it won't fit into the tiny space in my device.

The Murata board people speak about, I've read the specs, but it doesn't mention anything about charging NI-MH batteries, as said i don't know that much about electronics, just soldering and basic knowledge...

Someone in another forum gave me this link:

1-8S 1.2V-9.6V NiMH NiCd Rechargeable Battery Charger Charging Module Board Input DC 5V

Only US$5.99, buy best 1-8s 1.2v-9.6v nimh nicd rechargeable battery charger charging module board input dc 5v sale online store at wholesale price.

www.banggood.com

It looks good, it's' quick/cheap to buy, the size is perfect and does exactly what I need (the 2 cell version),
but, I have one question, how do I hook up the device to it?
When the battery is charging, where do I hook up the device's power input to so it gets powered from the board while the battery is charging...
Can I just attach it to the battery terminals too ???

Terrence

Terrence

 

[radiance32]

Could you use a "USB power bank" board and an appropriate sized LiIon battery? This type of module is probably easier to find.

Hi,
Sorry but it have to be NI-MH batteries as I plan to ship these devices world-wide,
and, our NZ post service often refuses to ship li-ion or li-poly batteries via airplanes,
to a ridiculous degree...
So NI-MH batteries are all I can use for this project...

 

[radiance32]

So if anyone could explain how i can hookup the device to this board:

1-8S 1.2V-9.6V NiMH NiCd Rechargeable Battery Charger Charging Module Board Input DC 5V

Only US$5.99, buy best 1-8s 1.2v-9.6v nimh nicd rechargeable battery charger charging module board input dc 5v sale online store at wholesale price.

www.banggood.com

Can i simply connect it to the battery/terminals, so give power to the device while the batteries are charging ?

I'd really appreciate it

Terrence

 

[gophert]

and, our NZ post service often refuses to ship li-ion or li-poly batteries via airplanes,
to a ridiculous degree...

UPS Airlines Flight 6 - Wikipedia

en.m.wikipedia.org