4.5V battery

M

Michael C

Guest
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
 
"Michael C"
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.
Click to expand...

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


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?
Click to expand...

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




............ Phil
 
Michael C wrote:
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


4 batteries (1.2v each) = 4.8 (a touch more than 4.5 but good enough)
Click to expand...
then add usb port
 
Michael C wrote:

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).
Click to expand...
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
 
"John_H" <john4271@hotmail.com> wrote in message
news:tsmgk1tjau76jb8dt904595bo1aiq4nj7b@4ax.com...
Michael C wrote:

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).

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.
Click to expand...
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
 
"Michael C"

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.
Click to expand...

** 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
 
Michael C wrote:
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.
Click to expand...
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
 
"Phil Allison" <philallison@tpg.com.au> wrote in message
news:3qs6daFg83dlU1@individual.net...
** Had to DRAG simple fact that out of the PITA prick.
Click to expand...
When I originally posted I didn't have that much space but came up with a
better way to do it.

Go check the WES catalogue for Akai Video Backup Batteries.

Cat # BVS8 = 4.8 volt, 80 mAH.

Costs = $10 .
Click to expand...
Thanks phil, I'll give them a call next week.

........ Phil
Click to expand...
 
On Sun, 09 Oct 2005 19:49:48 +1000, John_H <john4271@hotmail.com> put
finger to keyboard and composed:

Michael C wrote:

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.

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.
Click to expand...
How would you go about charging them from a 5V source?

-- Franc Zabkar

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

Four in series would give you 4.8 volt.

How would you go about charging them from a 5V source?
Click to expand...

** Boost regulator.



........... Phil
 
"Phil Allison" <philallison@tpg.com.au> wrote in message
news:3qtq9dFfh4i4U1@individual.net...
** Boost regulator.
Click to expand...
What's one of them then?

Michael
 
Michael C wrote:

"Phil Allison" <philallison@tpg.com.au> wrote in message
news:3qtq9dFfh4i4U1@individual.net...
** Boost regulator.

What's one of them then?
Click to expand...
LM2750 -- $5.81 from Farnell (awaiting stock).

--
John H
 
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