Good point, Ron. I like the AGM type of lead-acid deep cycle batteries,
like the Optima yellow tops.
Also remember to keep voltage drop as low as possible in the cable and
connectors. I tightened up the power socket pins on my Scout and
replaced the spring-loaded fuse and holder with the automotive blade
type. I wish that Ten Tec would dump the AMP connectors and go to power
poles.
73,
Bob WB2VUF
Ron Zond wrote:
> Hello Bob and Group
>
> I have used TEnTec rigs and battery power for about ten years, so the
> following observations might be relevant.
> The rigs were the Scout at 50 watts, and the Argonaut V at 20 watts. The
> batteries were 33 A\h gel SLA, a good weight\power density ratio. In all
> cases, regardless of rig, the 33 A\h batteries maintained a fairly constant
> voltage over
> a 12 hour period. The change would be .3 volt at most. I wonder if running
> the Orion at reduced power (CW 5 to 30 watts)
> would be suitable? Also, I would like to know your thoughts on using
> batteries in parallel with power supply
> as a voltage regulator\charger? Interesting post; thanks for any comments
>
> Ron
> K3MIY
> k3miy@csonline.net
>
> -----Original Message-----
> From: tentec-bounces@contesting.com
> [mailto:tentec-bounces@contesting.com]On Behalf Of Robert & Linda McGraw
> K4TAX
> Sent: Thursday, March 30, 2006 8:41 PM
> To: Discussion of Ten-Tec Equipment
> Subject: Re: [TenTec] battery life
>
>
> I've always figure the discharge of a lead-acid car battery at 50% of its
> rating. Example: 150 AH battery at 50% is 75AH. Now to draw 10 amps
> average, we must consider transmit at some 22 amps and receive at some 2
> amps average for about 50% of the time. Now, 75/10 = 7.5 hours. If you
> have a "hot shot" CW operator that runs 30 to 50 WPM then the duty cycle
> goes up and so does the average current. Therefore 10 amps may be a bit low
> for an average figure. If the bands are dead and you spend 95% of the time
> listening then the average goes down.
>
> In a 100% receive mode theoretically the battery would last, 75/2 or 37.5
> hours. The 2 amps is with min audio so expect the real current drain to be
> a bit higher. So we will take a more realistic approach and say 75/3 = 25
> hours.
>
> Other factors one must consider is the internal IR drop of the battery. New
> batteries are lower, old batteries are higher and deep cycle batteries tend
> to produce a higher voltage longer but at the expense of less current.
> Keep in mind that this radio is not going to like a voltage below about 12.8
> to 13 volts. It is rated at 13.8 VDC. A lead-acid battery open terminal
> voltage not under charge will likely be 12.8 to 13.5 depending electrolyte
> temperature. That takes a HOT battery, one that is very new and preferably a
> deep cycle marine battery. Therefore, a car battery is not the battery of
> choice as it is designed to be a "high current" device and that is not the
> application here. Based on this scenario, one could not expect a battery to
> provide much more than 25% of its rated AH value and thus for a 150 AH
> battery we now have 37.5 AH available. Again using our example, 37.5/10 is
> 3.75 hours of use time before required re-charge or a radio and associated
> internal processors getting flakey.
>
> OK, so one says we'll have two batteries, one to run on and one to charge.
> Not so fast on the draw cowboy. The correct charge rate should equal 2X to
> 3X the discharge time so 5 to 7.5 hrs will be required to restore the
> battery to full charge. Oh, one can do a fast charge but this raises the
> electrolyte temperature, plates and spaces expand and the capacity of the
> battery in terms of AH decreases. This gets us to the point that we need 3
> to 4 batteries to support the operation.
>
> In other words, the Orion II is a power hog and not really suitable for
> Field Day battery operation.
>
> One solution, use a good fresh marine deep cycle battery to power the radio,
> keep a charger attached and power the charger off of the generator. Using
> this method, the radio will have lots of current when needed, the battery
> acts as a big filter capacitor so humm from the charger is not a concern,
> and the battery acts as a voltage regulator to protect the radio from surges
> and generators as they "do their thing with changing loads", and when the
> generator dies or is down for refueling {you do shut it down don't you?} you
> can continue operating the station.
>
> 73
> Bob, K4TAX
> A connoisseur of fine radios
>
>
> ----- Original Message -----
> From: "Larry DiGioia" <listacct@longwire.com>
> To: "Discussion of Ten-Tec Equipment" <tentec@contesting.com>
> Sent: Thursday, March 30, 2006 5:56 PM
> Subject: [TenTec] battery life
>
>
>
>>I am looking for guesses as to how long an O2 would run, connected to a
>>reasonable large, fully-charged car battery, while operating CW for
>>Field Day...?
>>
>>--
>>Larry N8KU
>>
>>w w w . l o n g w i r e . c o m
>> 100% CW 100% HF
>>
>>_______________________________________________
>>TenTec mailing list
>>TenTec@contesting.com
>>http://lists.contesting.com/mailman/listinfo/tentec
>>
>
>
>
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