battery hot swap.

[Brad]

The next step in our project is to be able to hot swap the batteries
on the device and continue to run with out any interruptions.
Currently we are using 4 AA batteries. Currently draw is about 200
mA.

Do any of you have any ideas for a solution for something like this
where we could pull the batteries out and continue running for about
30 seconds until fresh batteries are inserted?!

Thanks for any information.

-Brad

 

[Jim Thompson]

The next step in our project is to be able to hot swap the batteries
on the device and continue to run with out any interruptions.
Currently we are using 4 AA batteries. Currently draw is about 200
mA.

Do any of you have any ideas for a solution for something like this
where we could pull the batteries out and continue running for about
30 seconds until fresh batteries are inserted?!

Thanks for any information.

-Brad

Depends on what your definition of "running" is.

Voltage?

Maybe just a big-valued capacitor?

Or two sets of batteries?

...Jim Thompson

 

[RFI-EMI-GUY]

The next step in our project is to be able to hot swap the batteries
on the device and continue to run with out any interruptions.
Currently we are using 4 AA batteries. Currently draw is about 200
mA.

Do any of you have any ideas for a solution for something like this
where we could pull the batteries out and continue running for about
30 seconds until fresh batteries are inserted?!

Thanks for any information.

-Brad

Insufficient information to answer your question. What is the device?
200MA sounds like a lot of continuous current for AA batteries. Maybe
you need a NICAD or NIMH rechargeable to maintain the operation while
changing batteries. But then how do you know that the primary batteries
are ready to go?

--
Joe Leikhim K4SAT
"The RFI-EMI-GUY"©

"Treason doth never prosper: what's the reason?
For if it prosper, none dare call it treason."

"Follow The Money" ;-P

 

[SoothSayer]

Depends on what your definition of "running" is.

Voltage?

Maybe just a big-valued capacitor?

Or two sets of batteries?

...Jim Thompson

Two set of batteries . Switch in the new batteries on the load, switch
out the old, and then the old can be replaced while the new, secondary
set are already in service. No extra cap bank circuits or storage
circuits needed.

Or put a crank storage module on it between battery swaps, the crank
bank would supply the needs.

 

[[email protected]]

  Two set of batteries .  Switch in the new batteries on the load, switch
out the old, and then the old can be replaced while the new, secondary
set are already in service.  No extra cap bank circuits or storage
circuits needed.

  Or put a crank storage module on it between battery swaps, the crank
bank would supply the needs.- Hide quoted text -

- Show quoted text -

You can logically OR the two supplies through diodes, if you can live
with the drop.

 

[Spehro Pefhany]

The next step in our project is to be able to hot swap the batteries
on the device and continue to run with out any interruptions.
Currently we are using 4 AA batteries. Currently draw is about 200
mA.

Do any of you have any ideas for a solution for something like this
where we could pull the batteries out and continue running for about
30 seconds until fresh batteries are inserted?!

Thanks for any information.

-Brad

Maybe you could use primary (eg. Lithium AA) cells with a long shelf
life just to supply that 200mA between changes. Usually, IME, with
that kind of situation the 'controller' powers down the stuff that
uses a lot of current, and just keeps enough stuff alive to maintain
the state. In that case, a double-layer capacitor may be enough.



Best regards,
Spehro Pefhany

 

[Eeyore]

The next step in our project is to be able to hot swap the batteries
on the device and continue to run with out any interruptions.
Currently we are using 4 AA batteries. Currently draw is about 200
mA.

Do any of you have any ideas for a solution for something like this
where we could pull the batteries out and continue running for about
30 seconds until fresh batteries are inserted?!

Well ..... if you wanted to use a cap to store charge, @ 200 mA, in
order to get a droop of 1 volt over 30 secs then the cap would have to
be 30 x 200 milli farads = 6 Farads !

Looks like you need a small back-up battery.

Graham

 

[Phil Allison]

"RFI-EMI-GUY"

200MA sounds like a lot of continuous current for AA batteries.

** Not true at all.

The common Energizer E91 alkalines will run 6 to 8 hours at 200mA -
depending on what end voltage is OK.

NiMH AA cells could bring that up to 12 hours or more.

Maybe you need a NICAD or NIMH rechargeable to maintain the operation
while changing batteries.

** One could switch over to a 9 volt battery to hold up the supply while
replacing in AAs.

But then how do you know that the primary batteries are ready to go?

** Bout the only way to do that reliably is to use NiMH AA cells and have a
strict routine of replacing them with a freshly recharged set every 8 to 10
hours.



....... Phil

 

[Jim Thompson]

You can logically OR the two supplies through diodes, if you can live
with the drop.

Or see how us big boys do it, take a look at...

PerfectDiodeForChargerIsolation.pdf

on the SED page of my website.

...Jim Thompson

 

[legg]

The next step in our project is to be able to hot swap the batteries
on the device and continue to run with out any interruptions.
Currently we are using 4 AA batteries. Currently draw is about 200
mA.

Do any of you have any ideas for a solution for something like this
where we could pull the batteries out and continue running for about
30 seconds until fresh batteries are inserted?!

Using each new battery to push out each old battery reduces hold-up
time requirements.

RL

 

[JosephKK]

Well ..... if you wanted to use a cap to store charge, @ 200 mA, in
order to get a droop of 1 volt over 30 secs then the cap would have to
be 30 x 200 milli farads = 6 Farads !

Looks like you need a small back-up battery.

Graham

I have seen 2 farad supercaps.

 

[linnix]

I have seen 2 farad supercaps.

You can get thousands F supercaps if necessary. For the size of 4 AA,
100F is possible (Wima supercap R 16x36x45 mm).

 

[PeterD]

I have seen 2 farad supercaps.

At 6 volts?

 

[sycochkn]

The next step in our project is to be able to hot swap the batteries
on the device and continue to run with out any interruptions.
Currently we are using 4 AA batteries. Currently draw is about 200
mA.

Do any of you have any ideas for a solution for something like this
where we could pull the batteries out and continue running for about
30 seconds until fresh batteries are inserted?!

Thanks for any information.

-Brad

2 sets of battery holders?

Bob

 

[Fred Bloggs]

The next step in our project is to be able to hot swap the batteries
on the device and continue to run with out any interruptions.
Currently we are using 4 AA batteries. Currently draw is about 200
mA.

Do any of you have any ideas for a solution for something like this
where we could pull the batteries out and continue running for about
30 seconds until fresh batteries are inserted?!

Thanks for any information.

Wrong buzzword, that's not a "hotswap" which has to do with plugging a
circuit into live power through some form of connector. The"swap" part
is close, but no cigar...

 

[JosephKK]

At 6 volts?

Elna has standard product of 1 farad at 6.3 volts, and in excess of 100
F at 2.5 volts.

 

[John Popelish]

PeterD wrote:

Elna has standard product of 1 farad at 6.3 volts, and in excess of 100
F at 2.5 volts.

Put three of Epcos B49410B2506Q000 5000F 2.5 volt caps in
series for a 1666F 7.5 volt cap.
http://www.epcos.com/inf/20/35/ds/B49410B2506Q000.pdf

 

[Martin Griffith]

Your idea will work but costly. He doesn't need any big Cap, all he has to do is to make sure a new battery is full charged before swapping. Insert the new battery in first before removing the old battery. It's so simple task to ask.

Jack

Tryv

<CR/LF>

occasionaly

martin

 

[Michael A. Terrell]

You got no brain.

Aren't mirrors wonderful? People like you can prance and pose in
front of them all day, yet you still see that you are an idiot.


--
Service to my country? Been there, Done that, and I've got my DD214 to
prove it.
Member of DAV #85.

Michael A. Terrell
Central Florida

 

[Phil Allison]

"Jak The Fuckwit Retard "

You too have a funny sound.

** LOL - this asinine prick sounds like a

STEAMING GREAT FUCKWIT !!!

Battery doesn't dictate the current draw,

** Err - where did I say otherwise ???

FUCKWIT !!!!!!



........ Phil