Sealed Lead-Acid Batts vs D Alkalines for Handheld radios?

[kosPap]

Greetings all!

I have 2 questions that bug me about batteries for Handheld radios.

I have both options for my handheld Kenwood (TH-F7). The Sealed Lead-Acid is wired to the carcharger with a suitable female plug, and I can wire a 4D size case to the radio's 4AA battery pack with dummy cells.

So both options are workable. But I would like to know the differences,

One is mAh....Lead-Acid is 7Ah but the 4D-size is about 25.000 mAh and does't that make 25Ah? So will I be getting a longer runtime with the D-cells? Why do not I believe I will?

One more issue is Amp Draw. My radio drops its output automatically at 0.5W when the 4AA pack is used instead of the Li-Ion rechargable battery. Is there a reason that D size Alkalines can stand to the necessary draw for 5 Watts ?

On the other hand, using the lead acid batt is just the same as plugin in the radio in the carjack...but this batt is not fielf replendishable/replacable...

Glad to draw from your experience, kostas

 

[Lynx_Arc]

Most alkaline battery *ratings* are based upon very small current levels around 24-50ma which IMO is useless for most calculations. I would estimate your radio at 5 watts draw off both the 7Ahr SLA vs 4D alkalines may get about the same runtimes. It is possible as the alkalines get to 1/2 life and the voltage drops to about 5.2-5.4v while the SLA is closer to 6.0v the radio could drop out sooner than the SLA. It is however possible the radio may work even off 3D cells as I have operated a 6D cells stereo off a 6v SLA which is well short of the starting 9v. Some equipment can tolerate higher voltage than normal also. I have run stuff using 1 extra battery (1.5v cell) fine and it can increase runtime off the normal cell usage by keeping the voltage level up longer. Try that at your own risk though.