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How to: NOCO charging system guidelines

Information on the design and performance of the Noco charging systems and how to maintain performance while at home and off grid.

The Noco system is not specifically designed to charge batteries and service 12V loads at the same time, but it can work well doing so.  The charger can provide at most 20 amps of charging. With the fridge using up to 10 amps and the fan 5 amps, you must manage your available power.

Both Noco chargers are wired into the trailers as described in the operating manuals - one charger to each battery.    It has been found that they function well, as long as the depth of discharge of the batteries is kept under control.   There is some troubleshooting information at the end of this article in case the chargers do enter an error state.


How do you keep the system charged?  

You need to always understand where you are.  At rest when neither charging nor servicing any loads some rough guidelines for the charge state of 12V deep cycle batteries are as follows:

12.6 volts = 100%           12.5 volts = 70%           12.3 volts = 50%           11.4 volts = 20%.

The batteries should never be allowed to get below 50% charge state. There are 110 amp hours in each battery, 220 total - which means that there are 110 amp hours of capacity available.  The only way to determine how fast your batteries will discharge is to do an experiment with your loads - ie: set up the trailer the way you're plan on using it, start with the battery fully charged, and measure the working time you get until the batteries are still at or above 12.3 volts.

As an example, one may suppose that the fridge uses only 6 amps.   This is truly dependent on temperature and the items inside the fridge.    In spite of that you could infer that the fridge would run for about 18 hours before the batteries were discharged to 50%. (110 amp hours / 6 amps = ~18.)

How do you best use this system while camping? First, you start with fully topped off batteries, so if the fridge is on or the system is electrically loaded while at home, the Noco charger should be plugged in.     Having the charger plugged in also helps with overall battery life, even if unloaded.

How can you keep your batteries topped off on the road and off grid?

- Charge with your tow vehicle (click the link below)

Keeping your trailer batteries charged with your tow vehicle

-  Solar panels can be attached via a suitable charge management system.


When shore power is again available, the Noco charger can be used to replenish the batteries.   



If you experience issues where one bank of the Noco charger is reporting a charged battery, and the other is reporting a dead battery or an error state, you can try unplugging the Noco system from shore power, waiting a few minutes (ideally, with a load on the batteries to help disappate any surface charge - you could run the rooftop fan, for instance,) and then reconnecting shore power.  The Noco charger should begin a new charge cycle and may exit the error state.


Also, it's important to read the Noco manual.   Below are some excerpts from the troubleshooting section:


There is a "force mode" you can try, to charge depleted batteries.  The mode button is held down for 7-10 seconds.   All modes will begin flashing, and the mode button can be again used to select the battery type.   The charge LED’s will then begin chasing which indicate force mode charging is in effect.


There is an "abnormality" error condition, described here:

This ERROR condition is the result of the battery charger being in the 
Bulk mode for more than eighty (80) hours. This ERROR condition is 
the result of a bad battery. To resolve this ERROR condition, take the 
battery to a local battery store for an evaluation.


There is a bulk charge timeout, described here:

For safety, if the charger is in bulk mode for 41 hours it will 
automatically stop charging and all LEDs will flash. If this 
happens, have the battery tested as it might be defective. To 
restart charging, disconnect AC Power and then reconnect. 


If you are still having troubles, it is very helpful to contact Noco support:


They have a live chat and phone service. 


You can also contact warranty@offgridtrailers.com, or call us and select the warranty option in the menu to speak to one of our technical services staff.