Correction to the previous post.
Finished the documentation about the box including the parts list

Keypad 4×4 buttons $3.00
Arduino Uno R3 $5.00
Can Bus Shield $13.00
2 Line character Display $12
Box 150x120x90 $13.00
Gyro module $5.00
2 4 Relais boards $18.00
2 DC-DC power supllies $2
1 16 DIO IO Expander shield $9.50
1 Screw shield $8
1 Temperature sensor $1
1 Voltage reference $1.20
1 Opto DC In board $8.95
1 I2C Hub $4.95
6 panel connectors $2.40
Cables & internal connectors $3.00

Total: $108

So not $85 .. cost was $108 .. original plan was higher because I thought I use two boxes and one with waterproof connectors.

Now I have only one box and cheaper panel connectors. Not that this is really important, but I thought I correct the figure that I am not being accused of exaggeration. :lol: :lol:
Considering what one can do with electronics nowadays and the cost involved .. and then you look at these totally overpriced caravan products. I mean, ok there is still a few steps to a marketable product, but all in all the cost of a product is usually less than 10% of the retail price with most of the price being marketing and middle man. I guess if I would have to integrate this onto one board and use MosFets instead of relays I could probably get the board produced at less than $10 for a medium quantity.

I still don’t understand why a MPPT charger or any of that kind of thing has to cost $400-$1000 depending on size. Well I cannot do everything myself but sometimes I get really annoyed by the lack of mental input into some of these products.

One of the next things I am going to to is the battery management system. I will also use a simple LCD first but was planning to use a little touch screen just for kicks .. not that I really need it, but I am curious to use one of the new displays from 4D systems.

Will post about this down the track ..