[RFI] quiet chargers?

[David E. Crawford]

Gary:  How old are your Battery Tenders?  The one I purchased, 12 VDC, 1.25 A, "Battery Tender Plus" model 021-0128, June 2023, is too 
white-noisy on MF/HF when used on a radio battery to keep it powered while operating.

I have an older 1.5 A Schumacher charger/maintainer (SEM-1562A) on the radio desk battery now.  It is much quieter than the newer Battery Tender 
but hasn't been getting the job done for a 100 AH Mighty Max AGM battery -- at least now that I put an older ICOM-756 Pro II on it that draws 3 
A just sitting there receiving.  A newer version of the same alleged Schumacher model was way too noisy on the radio desk, but is OK at the far 
end of the house keeping a "portable" (if you have a mule) generator starter battery maintained; clearly the design changed between my two 
Schumacher purchases.

The battery itself has probably failed (after 2 years), and once the voltage drops below low 12.x now it keeps crashing quickly down toward 
"nothing" with the 3 A load on it.  This just began the past week after a few months of operating with no such problems.  I'm just not sure yet 
whether a 1.5 A C+M cycle helped cause it.  I'm not the only one complaining about short Mighty Max AGM life either.  Once the voltage drops 
down to ~12 I had been just turning off the thirsty ICOM and waiting for it to charge back up.

At the same time, 1.5A is well below the recommended charging current for a 100 AH AGM.  So, I'd like to replace it with a 5 A charger, but need 
to find a quiet one.

So, I may have two problems feeding off one another to solve here.  A big linear supply for routine ICOM use is of course a solution for the 
noise, but also complicates the overall configuration.

Tnx.

On 2024-09-13 09:55, Gary Smith wrote:
> Batter tender is my favorite brand. Have three on my m/c’s when not riding.
> Gary…wa6fgi
> Sent from Gary’s iPad
> 
>> On Sep 12, 2024, at 10:14 PM, David E. Crawford <dcsubs at molniya1.com> wrote:
>>
>> Any make/model recommendations, based on direct experience, for an RF-quiet battery charger+maintainer, AGM or flooded deep cycle lead-acid, 12 VDC, 3 to 5 A rating?
>>
>> Thanks!
>>
>> --
>> -----------------
>> David E. Crawford
>> Indian River City
>> Florida Libre
>> -----------------
>>
>>
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-- 
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David E. Crawford
Indian River City
Florida Libre
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