[COUGAR]

[PREFACE: With my current set of projects coming to an end this week, I am going to finally find time to work on Project Nomad: to convert my Gypsy into an all-terrain mini-motor home. This is the first of the series of threads on this topic.]

I have fitted a secondary battery for power inside the Gypsy when in camping mode, so i dont discharge my main battery. I went for a 55AH Amaron sealed acid battery. A bigger deep cycle type battery would have been nice, but I wanted to avoid mounting the battery in the cabin to save space and the 55A battery was the largest that fit under the bonnet on the left side.

Right now the secondary battery is being charged OFF the primary battery with a manual cut-off switch inside the car. The switch disconnects the batteries to prevent the main battery from being discharged when in overnight use.

Primary Battery connections:
- Amplifier 2ch
- Carputer
- LCD-7"
- Fog Lights Hella 3000
- Cig Lighter Socket

Secondary Battery connections:
- 2x 90cfm Vent Fans with control switch. these run through the night when camping. rated consumption is 9A for 8 hours.
- 2x DC power outlets - 1L & 1R for laptops. Typically only one is used at a time.
- Rear cabin lights

In a typical use situation, I am driving 400+ kms followed by 2/3 days in which average driving is 50/60 kms or less. At night the secondary battery is in use for most of the time. With this kind of use the secondary battery gets discharged typically by day 3 since it is not being driven sufficiently to get fully charged. The battery also gets completely discharged in about 6 hours of laptop use.

To overcome this situation, I am now considering installing solar panels to charge the second battery. After evaluating options, i have chosen 37W mono-crystalline panels with the foll specs:
# Maximum Power (Pmax) - 37W
# Max. Power Voltage (Vmax) - 16.4V
# Max. Power Current (Imax) - 2.25A
# Open Circuit Voltage (Voc) - 21.0V
# Short Current Current (Isc) - 2.50A
# Dimensions (mm) - 966X430X34
# Weight - 5Kg

With 8 hours of sunlight, it should be possible to replenish lost charge everyday. The panel will be mounted on rails on the rear roof of the gypsy to enable easy mounting/dismounting to enable easy storage when not on touring duty.

Another idea in consideration, courtesy an electronics geek from this forum , is to fit in a zener diode borrowed from a UPS between the primary and secondary batteries to eliminate the manual cutoff switch.

All suggestions welcome!

[COUGAR]

Bumping up the thread with an update.

In the rear of the gypsy, i intend to put up a convertible seat which will be a front facing bench seat by day, but fold down into a bed by night. After 2 failed attempts - the last "drawer" design locked up on first camping out trial - I am now on the third attempt.

After trying in vain to explain the latest idea to the seat wala, i made a quick model out of some left over foam and this time i think he has understood what needs to be done!

The plan is to make the seat in 3 pieces: A - Backrest 30"x48", B- Base 21"x48", C- 21x48". Piece C folds over B in "seat-mode". 1-hook on each b-pillar will swivel around to support Piece-C as it folds over into a bed. When folded down it will be a 72"x48" lie-flat bed. 4" thick for the backrest and 2" thick for B and C. Seatwala says 2 U-shaped legs required: why not mount it on the wheel casing?

He has quoted 6k including faux rexine covers in red and black scheme and fitting. Will try and negotiate.

PS: The solar panel arrived and it "feels" heavier than what i had thought. Need to reexamine this plan.

[citron]

"With 8 hours of sunlight, it should be possible to replenish lost charge everyday. The panel will be mounted on rails on the rear roof of the gypsy to enable easy mounting/dismounting to enable easy storage when not on touring duty"

Hello Cougar,

This is an interesting project.

Please design your solar panel mounting arrangement to permit some tracking so that the face of the panel can be perpendicular to the sun rays for at least 4 of the 8 hours that you have considered. The efficiency of SPV panels may be drastically reduced otherwise, specially when driving with trees and other obstructions to sun rays.

All the best in your efforts!

[COUGAR]

Originally Posted by citron

Please design your solar panel mounting arrangement to permit some tracking so that the face of the panel can be perpendicular to the sun rays for at least 4 of the 8 hours that you have considered. The efficiency of SPV panels may be drastically reduced otherwise, specially when driving with trees and other obstructions to sun rays.

i was thinking the same too that some kind of tilting mechanism will have to be worked out. But it was getting too difficult, plus I am told that it is not necessary.

What is being planned is a carrier type system on the roof on which the solar panel be bolted on. Once i get back from tour, the solar panel will be dismounted and stored away.

[KALINGA]

A great project "COUGAR". Best of LUCK
I think this project is unique and only one of its kind in T-BHP.
it may open way for many DIY in T-BHP in future.
Excellent idea COUGAR ..carry on...

I must catch you on our next "PASHAN - SPECIAL" meet. Hope you will be available for this meet.

[Rehaan]

Very interesting project! Looking forward to see how it progresses, as well as some pics of your car as it currently is.

Originally Posted by COUGAR

....After evaluating options, i have chosen 37W mono-crystalline panels with the foll specs:...

Could you please provide us with a link to this panel, as well as the approx price?

Originally Posted by COUGAR

...i made a quick model out of some left over foam ....

One thing i can think of to perhaps improve on this design is to not waste the cushioned (seat) surface by having it face downwards in the bed configuration.

To continue to use the cushioned seat as-is, either you could flip the bottom piece of the seat forward and up

or

Have the cushioned seat slide forward and down slightly.

Though i guess its too late since the seat construction is already ongoing. Perhaps in the next version....

cya
R

[airbender]

Great work indeed. All the best. We need more projects like this to better utilize solar power.

[Chipz]

It is good to see people turning to renewable sources of energy. Is not the solar panel a bit costly. What are your backup plan on rainy days. External charging options ??

What is the use of the zenner

Is these vent fans useful for inside cooling when the doors are closed, and if you are opening the doors, what is the need for vent fans. Can you attach a photo.

[wanderernomad]

a very interesting project idea, I must say. Could you please post a few of the detailed drawings or pictures of what you propose to do? Also if you are only doing this to aid lighting and work during campings, did you give a thought to using an ultra portable small genset?

[srishiva]

You have got a interesting vehicle there. Could you post some pics of your ride? Best of luck with your efforts.

[COUGAR]

Originally Posted by Rehaan

One thing i can think of to perhaps improve on this design is to not waste the cushioned (seat) surface by having it face downwards in the bed configuration.

To continue to use the cushioned seat as-is, either you could flip the bottom piece of the seat forward and up

or

Have the cushioned seat slide forward and down slightly.

Though i guess its too late since the seat construction is already ongoing. Perhaps in the next version....

Version 2 of the design was to have the Leg portion of the bed concealed under the seat and would slide out like a drawer. Despite the high hopes it didnt work with the drawer getting jammed. Instead of tweaking that, i have decided to go ahead with this fold out version.

No more versions: if this doesnt work, we continue to sleep on the floor with sleeping bags as we do currently!



The second battery is for powering the appliances. if the solar panel cant be used due to rainy conditions etc then those appliances stay unused.

Not sure of the zener diode use. That was a suggestion from a fellow bhp-ian to basically prevent the secondary battery from discharging the main battery. Or something like that. ANyway that goes on later, as of now the 2 batteries are separate.

the vent fans (2 in number) are not designed for cooling but for air circulation, though some cooling does happen. The first few nights of camping in the gypsy made the importance of circulation very clear: especially when 2 people are sleeping.

The fans are of 90 cfm capacity and 120mm in dia. 2 vent holes have been made on each side in the cabin wall towards the rear. Both vent fans are pumping air out right now. Will try an rewire them so as to have one fan pump air in and other pump air out.

Originally Posted by wanderernomad

did you give a thought to using an ultra portable small genset?

a genset is very noisy. Cant really be used in the kind of situations that Nomad is going to be used in. Solar panels are cleaner and in the longer run cheaper.

PS: Name of the company supplying Solar Panels is ProtechUS, Bangalore based fellow. the panels are also available from BEL in pune.

will be working on this again from Thursday onwards. Just got back from Dajipur on the weekend and have a tonne of work.

[wanderernomad]

Could you post some pictures? And some of the gensets are not very noisy. Go check some of them out. I have seen one being used and outdoors a little noise gets absorbed real quick. You can even use to charge your secondary battery in case of a cloudy day or large canopy surroundings. And please do post some pictures especially the vent fans.
Regarding the folding bed have you tired some of the upmarket furniture stores. They have a chaise recliner kind of thing that can be folded into a recliner and unfolds into a single bed? Another option could be some sort of tier system like they have in the railways.

[wanderernomad]

Whats the update and progress on this?