24v to 13.8v DC/DC converter

[StrangeBrew]

No such thing as a free lunch and those battery boosters simply rob current to make up the voltage difference. Not sure i would want to deplete a battery down to the point the booster would not function. Batteries don't like that deep of a discharge.

Of course the power has to come from somewhere, no free lunch expected. However a well thought out system with one of these and a deep cycle battery or two could be just the ticket, just have to do some research and find out how much extra amperage this thing will draw in order to give you the extra voltage and go from there.

PS: It should be noted that I'm speaking of using something like this to overcome voltage drop while transmitting, it goes without saying that when your source battery voltage starts dropping off while not under load it's time to shut the station down.

 

[unit_399]

The problem with connecting batteries in parallel is that each battery won't discharge at the same rate. The internal resistance varies from one battery to another, so the battery with the lowest IR will flow more current and discharge faster than the one with the higher IR. Even two identical brand new batteries will have a different IR right out of the box.
To make a supply for portable use, I first disconnected the power transformer secondaries from an old Pyramid power supply I have.
Now, when I operate in the field, I use three 6-volt batteries in series and connect them directly to the rectifier inputs on the Pyramid supply . Set the output to 13.8 and it's good to go. You could use two 12 volt batteries in series (24 vdc), but using a 6 and a 12 (18 vdc) is a lot more efficient and generates far less heat.

- 399