Doctor,
Loved the diagram. Am always amazed at what can be done on a key board.
Ok...I know, you think it's crazy, but consider your over-thinking it. I run
into this problem all the time. Many forklift batteries are 24/36/48/ volts
and some are daisied into 120v dc output so that platforms can run tools
that are ac/dc. With so many, and so many types of batteries, I have to
charge, acid adjust, carbon arc connectors, tar seal, etc since these
batteries can run from $700 to $7k and are just really heavy and expensive.
Charge rates, heat, finish rates, etc are very important. Water level,
overcharging, and none use are the common death of batteries. Some customers
have batteries that are still excellent at 20 years of age. Simple care is
the key and one-time neglect is the death.
Simply consider this: One 12 volt battery, one 12v charger. Put another set
beside it, like in your diagram. Now two 12 bat and two chargers. Ok,
connect the positive of one to the negative of the other. You can use the 12
v off of each for a (center tapped) load, or connect a 24 volt load at the
zero negative and the 24v positive, as in your diagram. Now remember, each
battery still has it's own 12v charger connected. Each is getting charged
with 12v.
You could charge both with a 24 volt charger, from your zero post to your 24
positive post shown in the diagram.
You could also cut the wires off one of those 12 chargers at the charger
that are still connected to one of the 12v batteries, put those two wires
onto the two wires comming out of the other 12v charger as long as you use
at least one diode on the negative lead to keep the flow direction to the
battery and not back to the charger negative output on the attached negative
lead to the charger.
Of course you wouldn't do it that way, much simpler to just jump negative
post to negative post with a in-line diode. Also, because of 1/4 and 1/2
wave chargers, I put a diode on the positive lead also. This also stops the
capacitor affect of the battery to the charger.
I have charged many 24, 36, and 48v batteries with just one 12 v charger, a
bucket of 50 to 400 amp diodes, and a birds-nest of cables with alligator
clips. It cost me a lost less in electric bill than the 600 pound chargers,
a lot less heat, no risk of overcharging, and you get a equalization of so
many cells without cooking the plates out of the stronger cells.
Doing two 12v "car" batteries, a total of 12 cells and 24 v with one 12 v
charger does work and utilizes the on-board RV charger, requires no wires to
be run from the charger that are not already there at the house 12v battery.
Just leave everything connected as you find it, add the second 12v battery.
add a heavy lead from the existing positive post terminal to the negative
post of the new/added battery, connect the 24 volt load/device the positive
of the new battery and the negative of the old.
To charge: Take a light wire of the same gauge as now comming from the
charger negative of the same color if you can, use a 20 or 30 amp diode and
connect that wire to both ends of the diode. Paying attention to flow
direction of the diode existing battery to the new battery, connect the wire
with the diode from the negative post of the existing house battery to the
new added battery negative post. Do the same thing for the positive post
with the chargers positive lead attached to the positive lead of the
existing house battery, connect with in-line diode from the positive of the
existing house battery to the positive of the new added battery. Whatever
the voltage is in the house battery, it will keep at least that voltage in
the added battery.
The good news! Like in a motorhome with a house and engine start/run
battery, you can totally run down and deplete the one battery, without
depleting the other. You have just built a battery charger and battery
isolator simultaneously. All motorhomes must have this battery
isolator/charger diode set up, so that you don't wake up in the morning
realizing that your shore power failed, your house battey is dead, and you
can't start the coach either because it's battery is also dead. Same thing
in boats.
It works.
-Eddie- (713)694-8084 24hrs or email, EddieHuffstetter@hotmail.com
> More minds that Bill want to know. Tell us electrical engineers how it
> works.