Electrical Hookups When Camping?

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   StephenH, let me first define what I meant by "high current". That depends on what your alternator can produce at idle, which is quite a bit less than at normal engine operating speeds. My alt produces about 120A at idle. Subtracting engine electrical demands (electronics, ignition, radiator fans, etc) a net of about 75-80A is available.  Beware of aftermarket high current alternators because they are typically designed to produce their max current at high engine rpm, which actually reduces their idle current capacity in most cases. 
The problem is that the alt won't produce that 80A at its max output voltage. I get the 80A at more like 12.5V, above which it tapers off to zero at 14.4V. On top of that there are the resistive losses in the cables connecting the TV to the trailer. You're fighting voltage drops between two circuits that want to be at the same voltage. So you can't directly float charge your trailer batteries from your TV alt, unless you want to idle your TV for many hours, which is both impractical and inefficient.

However, by using short runs of heavy gauge conductors you can directly bulk charge the trailer battery, and then use solar or occasional ac charger operation to complete the charging process. Doing it that way I'd suggest at least 2/0 (preferably 4/0 cable) and short runs directly from the alternator terminals to the trailer battery with the vehicles parked nose to nose. Anderson style connectors can be used to connect the two. 

I plan to do something a little different to get around the voltage drop problem. My plan is to convert the trailer to 24V Li batteries and use dc/dc step up converters for charging. That eliminates the concern with voltage drops as well as eliminating the need for float charging entirely (Li batteries don't require it). 

But the simple way with short heavy gauge conductors and normal 12V PbA batteries should work fine as long as you have an alternative way to complete the absorption and float charge process, which does't need to be done every day. 

Before doing away with your generator I'd suggest both measuring your TV alternator capacity and also its fuel consumption at idle. My TV burns about 1/4-1/3 gallon per hour at idle with no load so its really pretty efficient as long as I keep the charge rates high and then shut it off. And the biggest benefit is its very quiet, I can barely hear it 20 ft away, compared to the high noise level of even a "quiet" inverter-generator. 

Poll Question: Do you use electrical hookups when you camp?
Poll Choice	Votes	Poll Statistics
Always	7	[17.95%]
Most of the time	12	[30.77%]
About half the time	9	[23.08%]
Not very often	10	[25.64%]
Never	1	[2.56%]
This topic is closed, no new votes accepted