Inverters and NiCd chargers

I recharge my Dewalt 14 volt batts with a modified sine wave inverter
all the time. Bottom line is that it depends... on the charger, and
on the inverter.

No two are alike.
 >> Stay informed about: Inverters and NiCd chargers 

David&Joan wrote:

> Not likely. Your "cheap square wave inverter" is probably a "modified square
> wave" as well. I haven't had much luck with the typical hand tool NiCd
> chargers with these inverters.
>
> David
> "Richard Lane" <rqlhgl RemoveThis @ieee.org> wrote in message
> news:433dbc82$0$4860$8b463f8a@news.nationwide.net...
>
>>I use a 19.2 v Sears drill to raise the sail on my Nonsuch 26 and find
>>that the 75 watt 115 v charger does not function on the output of my
>>cheap square wave inverter. Would it work with a "modified square wave"?
>>Dick
>
>
>
Thanks for your interest, I guess I'll have to wait till I have shore
power since "true sine wave" inverters cost more than the drill, Dick
 >> Stay informed about: Inverters and NiCd chargers 

waynebatrecdotboats DeleteThis @hotmail.com wrote in
news:1128125761.560476.239700@o13g2000cwo.googlegroups.com:

> I recharge my Dewalt 14 volt batts with a modified sine wave inverter
> all the time. Bottom line is that it depends... on the charger, and
> on the inverter.
>
> No two are alike.
>
>

My Black & Deckers charge from a 500W Tripplite inverter in the stepvan all
the time. It too is a modified sine wave inverter.

--
Larry
 >> Stay informed about: Inverters and NiCd chargers 

In my experience, with charging battery packs, the free standing charge
stations don't like inverters. Even my modified sine wave charger inverter
will overheat the internal components..

I'm told and have noted myself that the wall wart type seem to work fine.

If you still want to charge with a battery charge station, then be very
observant for overheating.


--
My experience and opinion, FWIW
--
Steve
s/v Good Intentions
 >> Stay informed about: Inverters and NiCd chargers 

Richard Lane wrote:
> I use a 19.2 v Sears drill to raise the sail on my Nonsuch 26 and find
> that the 75 watt 115 v charger does not function on the output of my
> cheap square wave inverter. Would it work with a "modified square wave"?
> Dick

Usually, the charger consists of a battery holder and a power brick that
goes into your 115/230v outlet. You could bypass the powerbrick if you
have a DC-DC converter (unstabilized, for this purpose) that supplies
the correct voltage. They're a few bucks if you need something <= 12v.
12v is easy Unfortunately, 19.2 v > 12v ... So maybe get a 7 to 9 v
drill is cheaper!

I use this to charge DC-powered non-12v small appliances that don't come
with their own "car adapter".

Kees
 >> Stay informed about: Inverters and NiCd chargers 

Kees Verruijt wrote:
> Richard Lane wrote:
>> I use a 19.2 v Sears drill to raise the sail on my Nonsuch 26 and
>> find that the 75 watt 115 v charger does not function on the output
>> of my cheap square wave inverter. Would it work with a "modified
>> square wave"? Dick
>
> Usually, the charger consists of a battery holder and a power brick
> that goes into your 115/230v outlet. You could bypass the powerbrick
> if you have a DC-DC converter (unstabilized, for this purpose) that
> supplies the correct voltage. They're a few bucks if you need
> something <= 12v. 12v is easy Unfortunately, 19.2 v > 12v ... So
> maybe get a 7 to 9 v drill is cheaper!
>
> I use this to charge DC-powered non-12v small appliances that don't
> come with their own "car adapter".
>
> Kees

I have a laptop 12v power supply with varyable output voltage up to 24v.
These should be as readily available in the US as they are here in UK. Try
an electronics shop such as Radio Shack.

Dennis.
 >> Stay informed about: Inverters and NiCd chargers 

Richard Lane wrote:

> I use a 19.2 v Sears drill to raise the sail on my Nonsuch 26 and find
> that the 75 watt 115 v charger does not function on the output of my
> cheap square wave inverter. Would it work with a "modified square wave"?
> Dick

I know a person that took a dead battery from a similar drill, opened
the battery case up and made themselves a simple adapter with a 10-12
cable that lets them clip onto a auto battery and run the drill off of
that. Those drills have DC motors and the voltage varies with the
speed, so it will work over a pretty wide voltage range. To get full
speed you would need to get up around the rated voltage (14.4, 19.2,
etc.).

This adapter was made by cutting open the battery case, removing all the
dead/useless cells, soldering wires to the contacts, and "potting"
everything into place and reclosing the battery case with Liquid Nails
construction adhesive. It was more a tribute native cunning and
inventiveness than professional engineering but it works very well to
manipulate the leveling jacks on a RV.

Another option might be to check the output voltage from your 115V
charger and then look for a DC-DC adapter (for one of the older laptops
or something like that) with a similar output voltage and amperage rating.

I'm a little confused about how to do the latter method though. The
battery charger for my DeWalt 14.4V drill has an output voltage of 42V
as measured across the charging contacts. That is apparently DC, it
does not fluctuate any on my meter. The charged batteries are in the
13-14 Volt range. I think the 42V charger voltage is because the rated
voltage of all the cells (in series) totals a little less than 42V or
something like that. Maybe one of the electrical gurus here can explain
that.

Jack

--
Jack Erbes in Ellsworth, Maine, USA - jackerbes at adelphia dot net
(also receiving email at jacker at midmaine.com)
 >> Stay informed about: Inverters and NiCd chargers 

Jack Erbes wrote:

> Richard Lane wrote:
>
>> I use a 19.2 v Sears drill to raise the sail on my Nonsuch 26 and find
>> that the 75 watt 115 v charger does not function on the output of my
>> cheap square wave inverter. Would it work with a "modified square wave"?
>> Dick
>
>
> I know a person that took a dead battery from a similar drill, opened
> the battery case up and made themselves a simple adapter with a 10-12
> cable that lets them clip onto a auto battery and run the drill off of
> that. Those drills have DC motors and the voltage varies with the
> speed, so it will work over a pretty wide voltage range. To get full
> speed you would need to get up around the rated voltage (14.4, 19.2, etc.).
>
> This adapter was made by cutting open the battery case, removing all the
> dead/useless cells, soldering wires to the contacts, and "potting"
> everything into place and reclosing the battery case with Liquid Nails
> construction adhesive. It was more a tribute native cunning and
> inventiveness than professional engineering but it works very well to
> manipulate the leveling jacks on a RV.
>
> Another option might be to check the output voltage from your 115V
> charger and then look for a DC-DC adapter (for one of the older laptops
> or something like that) with a similar output voltage and amperage rating.
>
> I'm a little confused about how to do the latter method though. The
> battery charger for my DeWalt 14.4V drill has an output voltage of 42V
> as measured across the charging contacts. That is apparently DC, it
> does not fluctuate any on my meter. The charged batteries are in the
> 13-14 Volt range. I think the 42V charger voltage is because the rated
> voltage of all the cells (in series) totals a little less than 42V or
> something like that. Maybe one of the electrical gurus here can explain
> that.
>
> Jack
>
Yes those are certainly other alternatives however going via the NiCad
battery and then recharging reduces the peak current demand of directly
running the drill from the house battery via a 12/19.2v dc-dc inverter.
In fact I am thinking of replacing the NiCad cells with NiMH cells when
the two packs lose their charge taking ability and so achieving
increased AH.
Dick
 >> Stay informed about: Inverters and NiCd chargers 

"Steve" <estevew RemoveThis @hctc.com> wrote in news:DPSdne3EP8SwLaPeRVn-
vA RemoveThis @whidbeytel.com:

> I'm told and have noted myself that the wall wart type seem to work fine.
>
> If you still want to charge with a battery charge station, then be very
> observant for overheating.
>
>

For those with LESS than 12V battery packs only:

If you want to charge these packs in the boat, the solution is quite
simple. Use a voltmeter to determine which wire is + and -. Cut the wires
off at the stupid wall wart.

Get a tail light bulb socket or use any socket you can plug a tail light
bulb into....just one filament, like a backup light bulb...almost any will
work of the bright ones. Put the bulb socket in series with the positive
lead to your house batteries so the current to the battery pack is limited
by the filament in series with it. The bulb also makes a great current
indicator as to how much current the pack is drawing. The center wire of
the bulb goes to the house battery. Wrap any exposed metal on the light
socket with tape to keep it from grounding out to anything...it's hot to
the battery now. Plug in the battery pack to the charging stand and the
bulb will glow fairly bright until the pack comes up to voltage (7.2 or 9V
packs) When you notice the bulb gets dimmer and the pack starts to get
warm...it's charged. DO NOT LEAVE IT CHARGING CONSTANTLY this way as the
charge will continue indefinately. You adjust the charging current,
therefore the charging time, by changing to different bulbs. I'm using 6V
high-intensity lamps instead of tail light bulbs to charge the packs
quicker with more current, but they will easily destroy a battery pack if
you forget and leave them on too long. The packs will overheat on them.
The slower you charge, the better for the packs, of course. Sailboaters
got plenty of time...(c; Never let the battery packs get warmer than your
coffee cup and you'll be fine.

There. Now you don't need to waste power on an inverter. There are 3 bulb
charging stations like this on the house batteries to my work stepvan
glowing in the yard as I type this.

For you perfectionists, buy a little voltmeter or hook your boat VOM across
the charging stand wires so you can watch the voltage rise.

--
Larry
 >> Stay informed about: Inverters and NiCd chargers 

Larry wrote:

> "Steve" <estevew.TakeThisOut@hctc.com> wrote in news:DPSdne3EP8SwLaPeRVn-
> vA.TakeThisOut@whidbeytel.com:
>
>
>>I'm told and have noted myself that the wall wart type seem to work fine.
>>
>>If you still want to charge with a battery charge station, then be very
>>observant for overheating.
>>
>>
>
>
> For those with LESS than 12V battery packs only:
>
> If you want to charge these packs in the boat, the solution is quite
> simple. Use a voltmeter to determine which wire is + and -. Cut the wires
> off at the stupid wall wart.
>
> Get a tail light bulb socket or use any socket you can plug a tail light
> bulb into....just one filament, like a backup light bulb...almost any will
> work of the bright ones. Put the bulb socket in series with the positive
> lead to your house batteries so the current to the battery pack is limited
> by the filament in series with it. The bulb also makes a great current
> indicator as to how much current the pack is drawing. The center wire of
> the bulb goes to the house battery. Wrap any exposed metal on the light
> socket with tape to keep it from grounding out to anything...it's hot to
> the battery now. Plug in the battery pack to the charging stand and the
> bulb will glow fairly bright until the pack comes up to voltage (7.2 or 9V
> packs) When you notice the bulb gets dimmer and the pack starts to get
> warm...it's charged. DO NOT LEAVE IT CHARGING CONSTANTLY this way as the
> charge will continue indefinately. You adjust the charging current,
> therefore the charging time, by changing to different bulbs. I'm using 6V
> high-intensity lamps instead of tail light bulbs to charge the packs
> quicker with more current, but they will easily destroy a battery pack if
> you forget and leave them on too long. The packs will overheat on them.
> The slower you charge, the better for the packs, of course. Sailboaters
> got plenty of time...(c; Never let the battery packs get warmer than your
> coffee cup and you'll be fine.
>
> There. Now you don't need to waste power on an inverter. There are 3 bulb
> charging stations like this on the house batteries to my work stepvan
> glowing in the yard as I type this.
>
> For you perfectionists, buy a little voltmeter or hook your boat VOM across
> the charging stand wires so you can watch the voltage rise.
>
I suppose one could break into the 19.2/1.2= 16 cells string and either
fit a series to parallel switch or simply a centre tap allowing charging
from 12v.
Dick
 >> Stay informed about: Inverters and NiCd chargers 

Richard Lane wrote:
> Larry wrote:
>
>> "Steve" <estevew.DeleteThis@hctc.com> wrote in news:DPSdne3EP8SwLaPeRVn-
>> vA.DeleteThis@whidbeytel.com:
>>
>>
>>> I'm told and have noted myself that the wall wart type seem to work
>>> fine.
>>>
>>> If you still want to charge with a battery charge station, then be
>>> very observant for overheating.
>>>
>>>
>>
>>
>> For those with LESS than 12V battery packs only:
>>
>> If you want to charge these packs in the boat, the solution is quite
>> simple. Use a voltmeter to determine which wire is + and -. Cut the
>> wires off at the stupid wall wart.
>>
>> Get a tail light bulb socket or use any socket you can plug a tail
>> light bulb into....just one filament, like a backup light
>> bulb...almost any will work of the bright ones. Put the bulb socket
>> in series with the positive lead to your house batteries so the
>> current to the battery pack is limited by the filament in series with
>> it. The bulb also makes a great current indicator as to how much
>> current the pack is drawing. The center wire of the bulb goes to the
>> house battery. Wrap any exposed metal on the light socket with tape
>> to keep it from grounding out to anything...it's hot to the battery
>> now. Plug in the battery pack to the charging stand and the bulb will
>> glow fairly bright until the pack comes up to voltage (7.2 or 9V
>> packs) When you notice the bulb gets dimmer and the pack starts to
>> get warm...it's charged. DO NOT LEAVE IT CHARGING CONSTANTLY this way
>> as the charge will continue indefinately. You adjust the charging
>> current, therefore the charging time, by changing to different bulbs.
>> I'm using 6V high-intensity lamps instead of tail light bulbs to
>> charge the packs quicker with more current, but they will easily
>> destroy a battery pack if you forget and leave them on too long. The
>> packs will overheat on them. The slower you charge, the better for
>> the packs, of course. Sailboaters got plenty of time...(c; Never let
>> the battery packs get warmer than your coffee cup and you'll be fine.
>>
>> There. Now you don't need to waste power on an inverter. There are 3
>> bulb charging stations like this on the house batteries to my work
>> stepvan glowing in the yard as I type this.
>>
>> For you perfectionists, buy a little voltmeter or hook your boat VOM
>> across the charging stand wires so you can watch the voltage rise.
>
> I suppose one could break into the 19.2/1.2= 16 cells string and either
> fit a series to parallel switch or simply a centre tap allowing charging
> from 12v.
> Dick
Do you think that a 60 Hz series resonant LC circuit might provide
enough filtering to allow the use of a modified sine wave inverter?
Dick
 >> Stay informed about: Inverters and NiCd chargers 

I've been looking at true sine wave inverters on eBay. 300 watts for about
$150. Could be good for the laptop as well.

"Richard Lane" <rqlhgl.DeleteThis@ieee.org> wrote in message
news:433e1732$0$4861$8b463f8a@news.nationwide.net...
> David&Joan wrote:
>
>> Not likely. Your "cheap square wave inverter" is probably a "modified
>> square
>> wave" as well. I haven't had much luck with the typical hand tool NiCd
>> chargers with these inverters.
>>
>> David
>> "Richard Lane" <rqlhgl.DeleteThis@ieee.org> wrote in message
>> news:433dbc82$0$4860$8b463f8a@news.nationwide.net...
>>
>>>I use a 19.2 v Sears drill to raise the sail on my Nonsuch 26 and find
>>>that the 75 watt 115 v charger does not function on the output of my
>>>cheap square wave inverter. Would it work with a "modified square wave"?
>>>Dick
>>
>>
>>
> Thanks for your interest, I guess I'll have to wait till I have shore
> power since "true sine wave" inverters cost more than the drill, Dick
 >> Stay informed about: Inverters and NiCd chargers 

"Gordon Wedman" <PacG DeleteThis @telus.net> wrote in
news:rCf0f.291283$tt5.93571@edtnps90:

> Could be good for the laptop as well.

Switching power supplies like the laptop could care less. The first thing
they do is digest any waveforms fed to them into unregulated DC to feed the
hungry power FETs doing the switching. Notice how it says any voltage is
fine between 85 and 280VAC at any frequency?

--
Larry
 >> Stay informed about: Inverters and NiCd chargers