Charger for Yaseu FT290R Mark II with NiMH batteries??

  • Thread starter Geoffrey S. Mendelson
  • Start date
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Geoffrey S. Mendelson

Guest
About 16 years ago, I purchased an FT-290R II in the US. I now live in
Israel. I purchased the FBA-8 battery pack, and charger with it.

I have since lost the charger.

The FBA-8 holds 9 C batteries, which were either dry cells or NiCad
batteries. I have since replaced them with 2500mAh slow discharge NiMH
AA batteries in AA to C battery adapters.

They fit but did not work because the positive end of a C battery is
longer than a AA battery's one. I was able to make it work by placing
metal washers on top of the cells to make contact. They are held in
place by pressure.

Therefore I am loath to take the cells out and charge them in a standard
AA charger, it would require opening the FBA-8, removing each cell from
a sleeve, charging them and then assembling the FBA-8 by placing them
back in the sleeves, getting the washers in the correct position and
snapping it back together.

The FBA-8 has a charger connection, which according to the manual is
just a direct connection to the batteries. Since I no longer have the
original charger, I am at a loss as to how to charge it. I don't have a
12 volt "smart" battery charger, but I have many 12 volt "transformers",
aka wall-warts, etc. Some are rated for a few hundred ma, some for 1amp,
and some for 2amps. Most are unregulated.

Note that the FBA-8 has no overcharge or over current protection, it was
designed so that the internal resistance of the NiCad batteries would
limit the current draw from the charger, and the current supplied from
the charger would be low enough to not cook the batteries if you left it
on too long.

Unfortunately, I no longer have the charger, nor those conditions.

Any suggestions?

Thanks in advance,

Geoff.


--
Geoffrey S. Mendelson, N3OWJ/4X1GM
Making your enemy reliant on software you support is the best revenge.
 
Perhaps someone in the group will have a circuit for a regulated 12V
charger.

If not, I would experiment, starting with something simple. Stick a 25-ohm
resistor in series with the output of a 12V supply and see what happens.

If you want true constant-current charge, you'll need a higher voltage (25V,
perhaps?). You might, for example, put the battery in the collector circuit
of a power transistor and vary the base bias to get the charging current you
want.
 
The voltage of 9 rechargeable cells is 10.8V. If you can't come up with a
charger design that will prevent overcharging, the cells won't last long.
I have AA to C cell adapters that adapt the AA cells to the same size as C
cells, so that would be one option.

There are universal smart chargers that will charge battery packs from 4.8
to 10.8V in either NIMH or NICD.
The ones I use are Powerizer brand, and have international 120/240VAC input,
but the charge rate is manually set for 1A or 2A, which is likely too high
of a rate for your 2500mAh AA cells. Some would consider a 1A rate suitable,
but it depends upon the quality/grade of the cells.
Powerizer may have some models of universal chargers with a 0.5A/1A rate..
or you could buy some full size C rechargeables, which would have more
capacity than 2500mAh, and the universal 1A rate would likely be fine.

--
Cheers,
WB
..............


"Geoffrey S. Mendelson" <gsm@mendelson.com> wrote in message
news:slrnivgne2.q0s.gsm@cable.mendelson.com...
About 16 years ago, I purchased an FT-290R II in the US. I now live in
Israel. I purchased the FBA-8 battery pack, and charger with it.

I have since lost the charger.

The FBA-8 holds 9 C batteries, which were either dry cells or NiCad
batteries. I have since replaced them with 2500mAh slow discharge NiMH
AA batteries in AA to C battery adapters.

They fit but did not work because the positive end of a C battery is
longer than a AA battery's one. I was able to make it work by placing
metal washers on top of the cells to make contact. They are held in
place by pressure.

Therefore I am loath to take the cells out and charge them in a standard
AA charger, it would require opening the FBA-8, removing each cell from
a sleeve, charging them and then assembling the FBA-8 by placing them
back in the sleeves, getting the washers in the correct position and
snapping it back together.

The FBA-8 has a charger connection, which according to the manual is
just a direct connection to the batteries. Since I no longer have the
original charger, I am at a loss as to how to charge it. I don't have a
12 volt "smart" battery charger, but I have many 12 volt "transformers",
aka wall-warts, etc. Some are rated for a few hundred ma, some for 1amp,
and some for 2amps. Most are unregulated.

Note that the FBA-8 has no overcharge or over current protection, it was
designed so that the internal resistance of the NiCad batteries would
limit the current draw from the charger, and the current supplied from
the charger would be low enough to not cook the batteries if you left it
on too long.

Unfortunately, I no longer have the charger, nor those conditions.

Any suggestions?

Thanks in advance,

Geoff.


--
Geoffrey S. Mendelson, N3OWJ/4X1GM
Making your enemy reliant on software you support is the best revenge.
Click to expand...
 
In article <slrnivgne2.q0s.gsm@cable.mendelson.com>,
Geoffrey S. Mendelson <gsm@mendelson.com> wrote:

About 16 years ago, I purchased an FT-290R II in the US. I now live in
Israel. I purchased the FBA-8 battery pack, and charger with it.

The FBA-8 has a charger connection, which according to the manual is
just a direct connection to the batteries. Since I no longer have the
original charger, I am at a loss as to how to charge it. I don't have a
12 volt "smart" battery charger, but I have many 12 volt "transformers",
aka wall-warts, etc. Some are rated for a few hundred ma, some for 1amp,
and some for 2amps. Most are unregulated.

Note that the FBA-8 has no overcharge or over current protection, it was
designed so that the internal resistance of the NiCad batteries would
limit the current draw from the charger,
Click to expand...
Eww. Wall-wart with a really thin-gauge secondary, I'd guess...
built-in resistance limit.

and the current supplied from
the charger would be low enough to not cook the batteries if you left it
on too long.

Unfortunately, I no longer have the charger, nor those conditions.

Any suggestions?
Click to expand...
My understanding is that NiMH cells really do *not* do well if
overcharged (even at relatively low rates) - it's fairly important to
cut off the charge when they hit 100%. Failing to do so, shortens
their life considerably.

Doing this properly seems to require either a temperature sensor
connected to the battery pack (or one of the cells) to detect the
temperature rise at the full-charge point, or a NiMH-aware charge
control circuit which can detect the "zero delta V" point where the
battery's terminal voltage stops rising and begins to fall (a
secondary effect of the temperature rise, I believe).

There are dedicated NiMH charge-control ICs available. You might want
to see if you have enough room to pooge one (with the necessary
support circuitry and temperature sensor) into the FT-290R in between
the battery terminals and the "charger connection" point.

You maybe-could wire up a charge controller of this sort externally,
and depend on zero-delta-V detection (and not have a temperature
sensor) and/or a cutoff timer... but I'd expect poorer battery
lifetime under these circumstances.

Using some sort of actively-regulated current source (maybe just an
LM317 in current-source mode) rather than a resistor or a really lousy
wall-wart would probably be sensible.

--
Dave Platt <dplatt@radagast.org> AE6EO
Friends of Jade Warrior home page: http://www.radagast.org/jade-warrior
I do _not_ wish to receive unsolicited commercial email, and I will
boycott any company which has the gall to send me such ads!
 
I'm starting to think the OP would be better off buying two sets of NiMH C
cells and charging them outboard.

http://www.thomasdistributing.com/Maha-POWEREX-4000-mAh-C-Size-Rechargeable-NiMH-Battery_p_1066.html

http://www.thomasdistributing.com/-MAHA-MH-C808M-AA--AAA--C--D-Battery-Charger_p_244.html
 
On Jun 15, 2:24 am, "Geoffrey S. Mendelson" <g...@mendelson.com>
wrote:
About 16 years ago, I purchased an FT-290R II in the US. I now live in
Israel. I purchased the FBA-8 battery pack, and charger with it.

I have since lost the charger.

The FBA-8 holds 9 C batteries, which were either dry cells or NiCad
batteries. I have since replaced them with 2500mAh slow discharge NiMH
AA batteries in AA to C battery adapters.

They fit but did not work because the positive end of a C battery is
longer than a AA battery's one. I was able to make it work by placing
metal washers on top of the cells to make contact. They are held in
place by pressure.

Therefore I am loath to take the cells out and charge them in a standard
AA charger, it would require opening the FBA-8, removing each cell from
a sleeve, charging them and then assembling the FBA-8 by placing them
back in the sleeves, getting the washers in the correct position and
snapping it back together.

The FBA-8 has a charger connection, which according to the manual is
just a direct connection to the batteries. Since I no longer have the
original charger, I am at a loss as to how to charge it. I don't have a
12 volt "smart" battery charger, but I have many 12 volt "transformers",
aka wall-warts, etc. Some are rated for a few hundred ma, some for 1amp,
and some for 2amps. Most are unregulated.

Note that the FBA-8 has no overcharge or over current protection, it was
designed so that the internal resistance of the NiCad batteries would
limit the current draw from the charger, and the current supplied from
the charger would be low enough to not cook the batteries if you left it
on too long.

Unfortunately, I no longer have the charger, nor those conditions.

Any suggestions?

Thanks in advance,

Geoff.

--
Geoffrey S. Mendelson,  N3OWJ/4X1GM
Making your enemy reliant on software you support is the best revenge.
Click to expand...
What is a Yaseu FT290R Mark II?
 
On Wed, 15 Jun 2011 11:14:21 -0700 (PDT), "hrhofmann@att.net"
<hrhofmann@att.net> wrote:

What is a Yaseu FT290R Mark II?
Click to expand...
<http://www.rigpix.com/yaesu/ft290rii.htm>
<http://www.radiomuseum.org/r/yaesu_ft_290rii.html>

--
Jeff Liebermann jeffl@cruzio.com
150 Felker St #D http://www.LearnByDestroying.com
Santa Cruz CA 95060 http://802.11junk.com
Skype: JeffLiebermann AE6KS 831-336-2558
 
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