[Motorola] NTN1171A Rapid Charger for HT1000 Radios

Sat Jul 5 17:05:34 EDT 2014

We think alike.  I do have a Battery Maintenance System Plus unit with six
stations, and an adapter for HT1000 batteries- among many others.  The BMS+
does "know" which chemistry is in the pocket, and reacts accordingly.
However, I still want a rapid single charger that I know is safe for my NiMH
battery.  I will sniff around on eBay to see what is available.  Thanks!

73, Eric Lemmon WB6FLY

-----Original Message-----
From: Motorola [mailto:motorola-bounces at mailman.qth.net] On Behalf Of KB0NLY
Sent: Saturday, July 5, 2014 1:54 PM
To: Discussion of equipment manufactured by Motorola
Subject: Re: [Motorola] NTN1171A Rapid Charger for HT1000 Radios

Most likely big M is going to just form letter you the specs on that charger
and repeat what you already know.  Been there done that.

Given the cost of the batteries I would just buy the RPX4747A to be safe. 
They run around $20-$30 on eBay, I got one off there for $29.99 brand new in
the box about two months ago. Cheap investment given the cost of the
batteries.

Your other option would be an aftermarket NiMH charger with a pocket for the
correct battery, I have a few of them from ArrowMax that have served me well
and at least they can charge more then one model with a quick swap of the
pockets.  I built a fixture for one with three pockets and a rotary switch
to select the different pockets.  Looks a little hodge podge but works great
for bench use.

73,

Scott KB0NLY

-----Original Message-----
From: eric lemmon
Sent: Saturday, July 5, 2014 3:47 PM
To: 'Discussion of equipment manufactured by Motorola'
Subject: Re: [Motorola] NTN1171A Rapid Charger for HT1000 Radios

Scott,

Thanks for the response.  I, too, know of folks charging NiMH batteries with
the 1171A charger, but Motorola states unequivocally that the 1171A is for
NiCd batteries only, and has been replaced by the RPX4747A for NiMH and
NiCd.  The three-contact models do, in fact, monitor the temperature sensor
inside NiCd batteries.  However, as Bob Meister wrote in a Repeater-Builder
article, the trip points in some such chargers must be modified to avoid
damaging a NiMH battery, unless the charger can detect which battery
chemistry is in the pocket.

Before even experimenting with an expensive NiMH battery, I'd like to know
whether the four-contact NTN1171A is an early production version of the
RPX4747A charger that is appropriate for NiMH, or not.

Monday morning, I will open a case on MOL to get Motorola to answer the
question.

73, Eric Lemmon WB6FLY

-----Original Message-----
From: Motorola [mailto:motorola-bounces at mailman.qth.net] On Behalf Of KB0NLY
Sent: Saturday, July 5, 2014 10:28 AM
To: Discussion of equipment manufactured by Motorola
Subject: Re: [Motorola] NTN1171A Rapid Charger for HT1000 Radios

I know of 1171A's being used to charge NiMH batteries but I don't know for
sure if its Motorola recommended.  I do know that generally the ones with
four contacts are rapid chargers with the thermal sensor input that can
handle NiMH, the three contact models are just dumb slow chargers though
some of the three contact models had a circuit in them that would light an
LED and turn it green based on battery voltage or current draw to indicate
fully charged, its been a long time since I went over the schematics for
one.

One thing I always hated about the 1171A is that when the light goes green
the battery is only about 80% charged, so most people that are in a hurry to
charge it won't ever fully charge the battery.  You have to let it go green
then wait another hour or so.  What I would do is put your NiMH battery in
the 1171A and closely monitor it and see if it starts getting hot, if it
does then don't use it for NiMH.  The NiMH chargers really only add a
thermal sense input to let the charger know if the battery is too cold or
too hot and stop charging.

73,

Scott KB0NLY

-----Original Message-----
From: eric lemmon
Sent: Saturday, July 5, 2014 9:20 AM
To: Motorola-Radius at yahoogroups.com ; 'Discussion of equipment manufactured
by Motorola'
Subject: [Motorola] NTN1171A Rapid Charger for HT1000 Radios

I have several NTN1171A Rapid Chargers for HT1000 portable radios.  I
noticed that some of them have four spring contacts while others have only
three.  I opened one of each to see what was different.  The three-contact
PCB has a part number of 8480648C01-P6, while the four-contact board has
part number 766V-A.  There are significant differences between them in
component count and layout.

I know that the NTN1171A charger is to be used only with NiCd batteries, and
was replaced by the RPX4747A charger, which can charge both NiCd and NiMH
batteries.  The RPX4747A is now NLA, so I can't examine its PCB to see if it
might resemble the 766V-A PCB.  Neither my HT1000 nor my Visar manuals
include any information about the NTN1171A or the RPX4747A chargers.

I am well aware that a NiMH battery can be toasted if placed in a NiCd-only
charger, and I don't want to risk damaging a new NiMH aftermarket battery.
I wonder: Is it possible that the four-spring version of the NTN1171A is
actually an early embodiment of the RPX4747A?  Moreover, is it safe to use
the four-spring NTN1171A to charge NiMH batteries?

73, Eric Lemmon WB6FLY

______________________________________________________________
Motorola mailing list
Home: http://mailman.qth.net/mailman/listinfo/motorola
Help: http://mailman.qth.net/mmfaq.htm
Post: mailto:Motorola at mailman.qth.net

This list hosted by: http://www.qsl.net
Please help support this email list: http://www.qsl.net/donate.html

______________________________________________________________
Motorola mailing list
Home: http://mailman.qth.net/mailman/listinfo/motorola
Help: http://mailman.qth.net/mmfaq.htm
Post: mailto:Motorola at mailman.qth.net

This list hosted by: http://www.qsl.net
Please help support this email list: http://www.qsl.net/donate.html

______________________________________________________________
Motorola mailing list
Home: http://mailman.qth.net/mailman/listinfo/motorola
Help: http://mailman.qth.net/mmfaq.htm
Post: mailto:Motorola at mailman.qth.net

This list hosted by: http://www.qsl.net
Please help support this email list: http://www.qsl.net/donate.html 

______________________________________________________________
Motorola mailing list
Home: http://mailman.qth.net/mailman/listinfo/motorola
Help: http://mailman.qth.net/mmfaq.htm
Post: mailto:Motorola at mailman.qth.net

This list hosted by: http://www.qsl.net
Please help support this email list: http://www.qsl.net/donate.html