High Output alternator

[junescomma]

I'm going for a "no frills" build on my 2017 NV 2500 V6.

Looking for advice on installing a Split charge (B2B) system. I'm hoping to reserve-power a Maxxair 0007000K (4A max) and supplying reserve power for charging phones and two 3.5w reading lamps.

My question is, generally, is the factory alternator adequate for the reserve power system, or do I need to install a high output alternator?

Also looking for suggestions on the inverter.

Thanks in advance.

Joe

[crusty]

Looking at what you describe, there is a very minimal electrical load. 

No, you don't need a bigger alternator. 

 

Adding a second battery?  Batteries only charge so fast.  Just because you have more potential (high output alternator) doesn't mean that the battery will accept a charge any faster.  Only if you get to the point where the alternator is running 100% will the alternator output be the limiting factor.  Even then that doesn't mean it won't charge, just the charge rate is slower.

 

When the power consumed exceeds the power generated, that is a time you need a bigger alternator.  In that case the battery will be discharging even though the alternator is running full power.  If you figure what the running power is, fuel pump, EFI, A/C compressor, A/C fan, secondary condensor fan, lets turn on the headlights and the wipers as well.  Driving at night in a hot thunderstorm.  You are probably drawing ~70A of power?  That is still 50A or so of charge potential. 

 

Now if you add a winch, that is a HUGE power sucker.  The big amp alternator can power a large portion of what a winch will take, in this case taking the stress off the battery.  On a hard pull with a big alternator the amp load on the battery might only be 150A instead of 250A.  So the big pull doesn't pull as much out of the battery, so you can make a bigger pull on the same size battery.

[junescomma]

No winches for me, but there'll be plenty of driving at night in a hot thunderstorm. Thanks crusty for your helpful response.

[Laura Bui]

Hello, I have a similar problem - mine is  campervan conversion on  NISSAN NV2500 SV High-Roof (4.0 Liter 6 cylinder).  Would there be any problems upgrading the alternator to a high output 250a or 360a alternator? Also, is there a brand that you would recommend for a Nissan NV2500? I currently have a Renogy 60a DC to DC charger that would charge 3 Renogy Lithium Iron Phosphate batteries 170a each (Total  510a), Warn 12,000 lbs winch, on-board air tank, driving camera, reverse/fog lights.  I've also upgraded the car battery to a Optima yellow top but for some reason the alternator wouldn't charge the car battery however, the I minute i disconnected the DC to DC 60a charger it would start to charge.  I appreciate any recommendations you may have.  Thank you.