4.5V battery

Do you have a question? Post it now! No Registration Necessary

Translate This Thread From English to

Threaded View


As I don't have the time or money (or knowledge) to design my own
electronics I'm taking an existing product and modifying it :-) It runs off
three 1.5V watch batteries in series. I'd like to replace this with a single
4.5V rechargable battery and charge it from a USB port. Does a 4.5 volt
battery exist that would take up a similar amount of space? What sort of
cicuit would I need to charge the battery (if any).

Many thanks,
Michael



Re: 4.5V battery



"Michael C"
Quoted text here. Click to load it


*  Yeah right -   like all " watch batteries" are exactly the same size.


Quoted text here. Click to load it


**  Errr  - how much space was that again  ???




...........  Phil



Re: 4.5V battery


Quoted text here. Click to load it
4 batteries (1.2v each) = 4.8 (a touch more than 4.5 but good enough)
then add usb port

Re: 4.5V battery



Quoted text here. Click to load it

If you have power available all the time it's no more difficult to
design and build a voltage regulator to eliminate batteries than a
battery charger.

AFAIK you won't get any rechargeable batteries that are compatable in
size to watch batteries.

Nor are watch batteries all the same technology.  The best and most
expensive are silver oxide, for which cheaper options exist if the
voltage stability isn't critical.

--
John H

Re: 4.5V battery


Quoted text here. Click to load it

Hi John,

The device is USB but it is wireless so won't always have power. I do have a
fair bit more space than the 3 watch batteries, probably enough for a single
AA battery. I was thinking that I could have a usb plug on the device that
was used for charging only, instead of supplying the customer yet another
charger.

Michael



Re: 4.5V battery



"Michael C"

Quoted text here. Click to load it


 **  Had to DRAG simple fact that out of the PITA prick.

Go check the WES catalogue for Akai Video Backup Batteries.

Cat  # BVS8   =  4.8 volt, 80 mAH.

Costs  = $10 .




........ Phil







Re: 4.5V battery


Quoted text here. Click to load it

When I originally posted I didn't have that much space but came up with a
better way to do it.

Quoted text here. Click to load it

Thanks phil, I'll give them a call next week.

Quoted text here. Click to load it



Re: 4.5V battery


Quoted text here. Click to load it

WES Components at Ashfield (NSW) list a 1.2V 80mAh NiMH that measures
16mm x 6mm (tagged for PCB mounting).  It's code no. is RB80.  They're
somewhat more expensive than watch batteries (probably close to
double).

Four in series would give you 4.8 volt.

--
John H

Re: 4.5V battery


finger to keyboard and composed:

Quoted text here. Click to load it

How would you go about charging them from a 5V source?

-- Franc Zabkar

Please remove one 'i' from my address when replying by email.

Re: 4.5V battery



"Franc Zabkar"

Quoted text here. Click to load it


 **   Boost regulator.



..........  Phil



Re: 4.5V battery


Quoted text here. Click to load it

What's one of them then?

Michael



Re: 4.5V battery



"Michael C"
Quoted text here. Click to load it


  **   Try Google.


.........  Phil



Re: 4.5V battery



Quoted text here. Click to load it

LM2750 -- $5.81 from Farnell (awaiting stock).

--
John H

Site Timeline