[FreeBay] Re: HTX-202 charger

[Richard]

A 100mA wall wart most likely will not overcharge NiCads because it cannot
supply enough current to do so. Charge management circuitry shouldn't be
necessary.

Richard, N7TGB


-----Original Message-----
From: freebay-bounces at mailman.qth.net
[mailto:freebay-bounces at mailman.qth.net]On Behalf Of Doug Younker
Sent: Monday, September 25, 2006 3:05 PM
Cc: freebay at mailman.qth.net
Subject: Re: [FreeBay] Re: HTX-202 charger


Hey nothing to be sorry about, Rick.  I mention if I recall correctly, I
didn't, I stand humbly corrected. When I purchased my 202, I ordered the
service manual.  I referred to it before my other post.  Maybe my
bifocals weren't setting square on my face, I don't know, but I didn't
see the battery circuit off to the side of the schematic.  I just
scanned it, if anyone needs a copy email me directly, I'll return a copy
via email.  Just give me a bit of time to clean it up, and write down
the component values.--73
Doug, N0LKK
Kansas USA inc.


qrp_1 at juno.com wrote:

> Doug, N0LKK [snip]
>
> Sorry Doug, but they are 12 volt 100mA chargers.  And you can even charge
> the batteris from a plain cable direct to the cigar plug in your car.
> The battery packs are 7.2 volt but they have a small regulator/charger
> circuit built in to bring the 12 volts down to the proper voltage/current
> level.  I just run a cable from the back of my 13.8 volt 20 amp Yaesu
> power supply and plug it into my 202 packs to keep them charged up and
> keep the little wallwart charger in a bag I use when I travel.  As for
> the dry cell case, get some nickel metal hydride rechargeables that are
> rated at 2300 mA to put in them and get a charger that will handle at
> least 6 of them and you can keep one set on charge while the other set is
> in the radio.
>
>> Yes, you can charge any 12volt battery by connecting it to a 13.6vdc
>> supply, but how you connect it and how well you limit the current drawn
>
>> may make a big difference in if you will ever be able to use tha
> battery
>> again. [snip]
>
> As I said above, the 202 battery packs have a built in charge controller
> to prevent damage to the batteries.  Somewhere around here, I even have
> the schematic for the built in charge controller !
>
> I just got the wall wart charger out that came with my 202 and measured
> the output voltage.  With no load, it measures 16.1 volts - enough to
> cook a nicads without some sort of regulation, and thats why the battery
> packs on the 202's have the built in charge controllers.  Plus, evidently
> the manufacturer of the battery packs had plans for a drop in fast
> charger - if you notice the 2 scews on the bottom of the battery packs,
> they are connected direct to the batteries and completely bypass the
> built in controller circuit.  The plug on the other hand goes direct to
> the controller circuit and then to the batteries.
>
> Rick McKee - KC8AON - Southern Ohio
> http://www.angelfire.com/electronic2/qrp
> http://www.angelfire.com/electronic2/qrp/forsale.html
> Monthly QRP Field Day Group: http://groups.yahoo.com/group/mqfd
> With God all things are possible <><
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