12 volt and 24 volt power options

[BRUISER]

so my bus is still 24volt and everything works great.. but as I modify it more I find the need for 12 volt stuff

has anyone added a 12 volt alternator to the side of there engine and just used that for all the 12 volt accessories? to a different battery system then the 24 volt stuff?

if you have do you like it? do you have the 12 volt stuff being charged while docked or when gen is running also? or do you just rely on charging when bus is running?

thanks
ken C

[Oonrahnjay]

(snip) has anyone added a 12 volt alternator to the side of there engine and just used that for all the 12 volt accessories? to a different battery system then the 24 volt stuff?  if you have do you like it? do you have the 12 volt stuff being charged while docked or when gen is running also? or do you just rely on charging when bus is running?

    Yes.  Works great.  And yes, the 12v battery set is wired to the inverter as the "house battery" (there are separate batteries wired in series and connected to the starter as "start batteries"); anytime the inverter sees power from the shore cord or the generator, it's charging the 12v batteries.  Only drawback I've found is that the cables to the inverter have to be large-gauge to carry the 12v power (versus the 24v, which would be half the amps) but that's not a big problem.  (If you don't want to run an inverter, you could do the same thing with a "converter" or a hard-wired battery charger.)

[TomC]

Just to show you what a truck type Leece-Neville 12vdc 160amp large case built in regulator alternator costs- $160.00 new.  Good Luck, TomC

[bevans6]

I run my 12 volt loads from my 24 volt house system that has a Vanner equalizer.  I charge it directly with my bus alternator at 24 volts, and run my 3000 watt inverter from it as well.  The inverter is the killer application, my house 12 volt loads amount to maybe 30 amps if everything was turned on at once.

Brian

[BRUISER]

I guess I need to trace some wires on my bus..

all my lights in bus are 12 volt lights..

bus currently has a converter all wired up and I was told from previous owner that when plugged in to shore power or when gen is running the 12 volt battery in back is being charged from converter.( do converters charge batteries also? )

So I guess if I run gen when driving then I should be able to pull 12 volt power off those batteries and be fine..

if this actually the case is it worth installing 12 volt alternator also?

[bevans6]

In a typical RV the converter is a dual purpose device - it supplies 12v for the house loads and charges the batteries with the left over.  Older converters, particularly the old Magnatek Parallax transformer type, are well known for catching on fire, and boiling batteries dry, so check what you have.  BestConverter.com sells a nice upgrade kit, I put one in my truck camper.  http://www.bestconverter.com/MagnetekParallax-63007300-Upgrade-Kit_c_64.html

Modern converters are computer controlled sophisticated chargers and power supplies.  Often they are biased towards power supply - they put out tightly controlled voltage and use current limiting to manage the charging.  They can often be set up to do multiple voltage charging if you want to focus on the charging part the deal.

Brian

[BRUISER]

well went into bus and look at converter: it is a MagneTek Series 7400 model: 7445

from what I searched it seems to be a good model

[napamikey]

I got a 50amp Vanner on ebay and hook it up to my 12v battery bank to charge on road.  They are pretty cheap and simple to use.
http://cgi.ebay.com/ebaymotors/Vanner-60-50A-Battery-Equalizer-USED-/300499265757

[Bill B /bus]

You have one of two ways to get the peanut eaten.  First is to have a 12 V alternator added to engine. Or shift back to 24V system. 

With a 24V system then your all 12V comes from an equalizer. Vanner is the most available and probably the least expensive. An equalizer provides the 12V at the center tap of the battery bank but draws equally from both 12V halves.
I have two equalizers the original installed unit for the various 12V stuff in the bus, radio, TV's, tape player etc. And a second one for all the house 12V stuff. And yes, I do have a crosstie in case one fails.


Most buses came with a 50DN alternator. Gear driven for the 2 stroke DD's or belt driven on the newer engines. Reliable and repairable. Output around 250 amps either 12 or 24V. About a 7KW at 24V. Understand 12V system is really about 13.5V and 24V system is really about 27V.  With a good sized inverter you can run a roof top AC, without running your generator, from  this alternator.

Bill