Tuesday, April 8, 2014

House battery backup alternator

I kept meaning to blog this mod but with everything going on I just forgot about it until now. Without going into too much boring detail, our bus operates on four separate electrical systems. System #1 is 24 volt DC for starting the Detroit with a split System #2 using a Vanner equalizer to make 12 volts DC for all running lights head lights, and systems like transmission control and gauges and window wash pump. System #3 is the 12 volt DC house batteries that power all interior lights and accessories associated with domestic living like vent fans, furnace fans, TVs, sound systems , water pumps and heat exchange heater. System #4 is 110V AC or "shore power" for things like microwaves, toaster ovens or vacuum cleaners.

Our problem was that if we were to drive through the night, or solar wouldn't be of any use at all until the next day which would tax our house batteries heavily if we were running the heat exchanger plus our fridge on 12V which drains 9 amps alone. If perhaps the next day brought heavy cloud cover, there would be some serious generator time to catch up on our reserves to get back to 100 percent.  

I can't take credit for installing the original accessory alternator but since it hadn't worked in many years, I can take credit for finding the exact replacement that not only fit perfectly but almost doubled the output from 80 amps to 145 amps so now when we fire up the Detroit, we're charging house batteries!

I suppose you might ask, "Why wouldn't you just use the engines original 24 volt 250 amp output to charge the house batts?" Here's the short answer, The Vanner equalizer can only handle about 50 amps of "split" to get from 24 volts to 12 volts and while that may be enough for running systems, lights and blinkers, I wouldn't want the extra load to take out my ability to start this beast when we're in the middle of nowhere. 
How do you install a right hand turn alternator on a left hand turn motor? Just turn it around backwards!

1 comment:

  1. Holy bud, your knowledge for the helictricals is pretty damn impressive. Cool stuff, kinda crazy to think about what all it takes to be able to microwave food when you don't have a power pole in front of your house to feed the plug-in on the kitchen counter.