What Watts?

Hi Here is a question for the clever ppl on the group
I have a small power pack to charge a nicade battery pack
its 240 volt and 14.3 v out at 60 ma
now Ii was thinking of buying a cheap inverter from dicks..$49 for a
12v to 230 v 150 watts....is 150 watts going to be enough to run the
charger?...I cant get 14.3 volts from my camper battery so this is the
only way I can see out of it
best regards Phill

 

[Phil Allison]

<bigjohn@hotmail.com>

Hi Here is a question for the clever ppl on the group
I have a small power pack to charge a nicade battery pack
its 240 volt and 14.3 v out at 60 ma
now Ii was thinking of buying a cheap inverter from dicks..$49 for a
12v to 230 v 150 watts....is 150 watts going to be enough to run the
charger?...I cant get 14.3 volts from my camper battery so this is the
only way I can see out of it
best regards Phill

** You could probably run 50 such chargers of that inverter.

Despite that - it is a cheap solution and useful for many other purposes.




........... Phil

 

[John Tserkezis]

bigjohn@hotmail.com wrote:

Hi Here is a question for the clever ppl on the group
I have a small power pack to charge a nicade battery pack
its 240 volt and 14.3 v out at 60 ma
now Ii was thinking of buying a cheap inverter from dicks..$49 for a
12v to 230 v 150 watts....is 150 watts going to be enough to run the
charger?...I cant get 14.3 volts from my camper battery so this is the
only way I can see out of it

Maybe not. Since your "power pack" is only 60mA, it's likely just a plain
power supply with a series current limiting resistor.

You may be able to duplicate this directly from your battery.

What is the voltage of the battery? A/h rating? What tool/appliance is it?

There may be other options rather than inverter, though, if you have other
uses for an inverter, it may still end up being the better choice.
--
Linux Registered User # 302622 <http://counter.li.org>

 

[KLR]

On Thu, 10 Jun 2004 12:02:49 GMT, bigjohn@hotmail.com wrote:

Hi Here is a question for the clever ppl on the group
I have a small power pack to charge a nicade battery pack
its 240 volt and 14.3 v out at 60 ma
now Ii was thinking of buying a cheap inverter from dicks..$49 for a
12v to 230 v 150 watts....is 150 watts going to be enough to run the
charger?...I cant get 14.3 volts from my camper battery so this is the
only way I can see out of it
best regards Phill

the inverter will handle this no problems at all. the charger will
only be likely drawing a couple of watts and 150W rating is more than
adequate.


the only problems you may have is

1> if the inverter needs a load in order to start (or even run
properly) - this charger might be too small to achieve this

2>that the charger might not like being run from an inverter and
refuse to work.

This problem happens with my DeWalt cordless drill charger
(transformerless design) and as I recall a mobile phone charger I once
had.

 

[Bob M]

Hi John,

Your charger draws 14.3 volts X .06 amps = .86 watts. Assuming an
efficiency of 45%, then .86 watts / 45% efficiency = 1.9 watts total
(it will probably be less). These calculations are based on a DC
output. Phil's estimate of 50 is being conservative.

Does your charger power pack output AC or DC? What is the voltage of
the Ni-cad pack you are trying to charge? If your power pack's output
is DC, you can probably connect your charger directly to your camper's
battery and charge your Ni-cad power pack just fine assuming your
charger is an inexpensive trickle charger, meant to charge a power
pack in the 9 volt or less range. You need to be careful to get the
polarity right. The lower charging voltage would likely result in a
lower charging current, so it might take a little longer to fully
charge the battery pack.

WARNING:

Please do not consider this route unless you or whomever is helping
you has a good understanding of electronic circuitry and can take the
necessary precautions. A camper battery is capable of much power and
can vaporize incorrectly connected devices.

The inverter route is an excellent way to get power to use for
anything you choose to connect. Using it charge your Ni-cad pack would
likely be VERY inefficient. Inverters typically draw several watts of
power with absolutely no load on them. The lighter the load, the less
the overall efficiency. You could end up drawing more than 10 watts of
"camper power" to provide less than 1 watt of "charging" power.

Cheers from Canada!

Bob M



"Phil Allison" <philallison@tpg.com.au> wrote in message news:<2ir1m2Fq5lhnU1@uni-berlin.de>...

bigjohn@hotmail.com
Hi Here is a question for the clever ppl on the group
I have a small power pack to charge a nicade battery pack
its 240 volt and 14.3 v out at 60 ma
now Ii was thinking of buying a cheap inverter from dicks..$49 for a
12v to 230 v 150 watts....is 150 watts going to be enough to run the
charger?...I cant get 14.3 volts from my camper battery so this is the
only way I can see out of it
best regards Phill


** You could probably run 50 such chargers of that inverter.

Despite that - it is a cheap solution and useful for many other purposes.




.......... Phil

 

[Yobbeaux]

<KLR> wrote in message news:ii6jc0l9gvb3i2n2d30hat8bjl0gdprrn1@4ax.com...

On Thu, 10 Jun 2004 12:02:49 GMT, bigjohn@hotmail.com wrote:

Hi Here is a question for the clever ppl on the group
I have a small power pack to charge a nicade battery pack
its 240 volt and 14.3 v out at 60 ma
now Ii was thinking of buying a cheap inverter from dicks..$49 for a
12v to 230 v 150 watts....is 150 watts going to be enough to run the
charger?...I cant get 14.3 volts from my camper battery so this is the
only way I can see out of it
best regards Phill



the inverter will handle this no problems at all. the charger will
only be likely drawing a couple of watts and 150W rating is more than
adequate.


the only problems you may have is

1> if the inverter needs a load in order to start (or even run
properly) - this charger might be too small to achieve this

2>that the charger might not like being run from an inverter and
refuse to work.

This problem happens with my DeWalt cordless drill charger
(transformerless design) and as I recall a mobile phone charger I once
had.

just get a dc - dc chip like these here dood!

http://www.calex.com/dcpcbsing1.html

theres a nice 1 watt job there that gives 15volt at 65ma from a 5 volt
supply

cheers big ears