CTEK 140a Charging System Bundle

Electrical Controller Was suggested by Hein Van Swaay
CTEK 140A Off Road Charging System Package
I used the CTEK 100A bundle of a Battery Monitor, Smartpass and D250S Dual.

This has been replaced by the 140A Bundle at a higher price including
CTEK 140-257 140A Off Grid Bundle-D250SA, Smart Pass 120 and Battery Monitor

The CTEK 100A has an electronically limited max charging current of 20 amps, and will only draw from the panels what’s needed to get up to 20 amps output. You can use as many panels as you want but it will only make use of 300 Watt. The obvious advantage is to make you self sufficient when standing for long periods in sunny and cloudy conditions without investing in a large battery bank.

CTEK arrived at the 500w array limit. They no doubt suggest that an array capable of a peak rating in excess of what the regulator will pass is useful in times when the solar radiation will not produce full output from that array. During those periods of diminished output you will get a higher charge current than if you only had a smaller panel just sufficient to drive the regulator in full light conditions. The 500w is about the point where value of the extra sized panel starts to become not worth going bigger.


CTEK Website (which is not very complete) is here 

The limit on the CTEK appears to be 20Amps
Links on the CTEK system worth reading



CTEK FAQS says 50 to 300 is recommended but a bit more is fine for cloudy days. 
Leo is tech support  CTek  312-967-1430 or email to  support@ctek.com

Electrical Design Blueprints

The designs from Hein were used extensively. I also was inspired by Orton’s work on his van. I think that Hein’s was the simpler to manage and install with less “remember to switch this to that” settings. I also have all of the wires labeled on a pdf.

Main Circuit board is located in the pantry area on the left side of the van. This is where all the battery cables go.

Above this near the ceiling is a bus that distributes to the overhead lighting.

In the sink area there is another bus planned (wired but not installed) that get’s it’s power from the Pantry via channels under the floor.

Fullriver DC220-6 27     6V 220 @ 20 HR  20 hour rate 5.25Volts

I am using these are my house batteries

These are Non Spillable AGM, Valve Regulated Lead Acid Rechargeable Batteries
The two 6 volts batteries are wired in series to give 12 volts
This gives a bit more Amps

The max recommended charge current remains 55A. The battery will accept up to 77A in scenarios that need rapid charging, but we do not recommend this be done often.

Complete specs are here
20 hour rate (11A to 5.25Volts) 220AH
10 hour rate (19.8A to 5.25Volts) 198AH
5 hour rate (36A to 5.1Volts) 189AH

Total Height8.90″ (226 mm)
Height8.66″ (220 mm)
Width6.85″ (174 mm)
Length12.05″ (306 mm)
Weight71.0 lbs (32.2 kg)


Solar Panel Notes

CTEK can handle 20A input limit I think
Using Flexible panels to keep the stealth program

Mount 2 before and one after the roof vent using
3M VHB and a strip of Eternabond on the front edges

Installation Instructions from Forum using


Other Different Panels are

5.29A Module Efficiency: 15.43%
https://www.renogy.com/renogy-100-watt-12-volt-flexible-monocrystalline-solar-panel/ 15% Efficiency

5.8Amp Module Efficiency: ??

5.8Amp Module Efficiency: ?? SUNPOWER Brand