Solar generator project

[4x4mike]

I've got some drawings and plans in my head for a portable power supply kind of like a small version of a Goal Zero generator. I want something relatively small as it will be enclosed in a box for travel and storage (think go box). My biggest question and first step is a battery. The plan is to have something in the 30-40 amp hour range in a relatively small package. I'd like to keep the cost under $100 but would like something more around $60.

What type of options do I have? Type, construction, etc. What should I stay away from?

The battery will receive a charge from a solar panel and regulated through a solar controller. I was thinking about a tractor or motorcycle battery because they are 12v and cheap. The battery will be stored up right and in box so gel cell type aren't required. Is there a certain type of common battery that puts up with low draw (for the most part) and charge from solar only?

The box will be used for charging of electronics, HAM and running mostly DC devices. I also plan to mount an inverter but it would be for intermittent use. As needs and demands increase I can up the battery, panel and inverter if need be. I imagine most of the 'generators' life will be in my garage powering my 2m radio I have out there. On busy weekends, call outs, events it may power a 2m radio for 4-10 hours, charge some phones and maybe some LED lights. I can do the calcs to determine the overall capacity of a battery and panel but need to know what type of battery will work best.

 

[madmax718]

Deep cycle marine batteries are your best bet for price. "upping" the battery will be costly, as the age of different batteries will not balance well. Get two if your thinking of expanding, and use both. It puts less wear and tear on the batteries the more batteries you have.

 

[4x4mike]

I'll have to look into small deep cycle batteries. I know I've seen small 6 volt ones that are run together for 12v in RV systems but size is an issue.


I did a little more reading and what I'm wanting to build is something similar to what one might build to power a 4WheelCamper, pick up bed mounted camper. Small system with solar. A lot of those guys are just using car batteries.

From what I know batteries don't like to be drawn down a lot and like just having the top used while it's being recharged. My load will dictate my panel size but I'd like the capacity because smaller (say 10 w) panels don't put out a lot of amps. I think my radio at high pulls 12 amps but I usually operate it from 6-8 amps on transmit.

 

[k9lestat]

ill see if i can find it, but i saw a dyi project where they made a goal 0 type kit. it consisted on a control box. it contained the charge control unit, the inverter, outlets and some other gizmos. then there was a series of three boxes( i forgot to mention the boxes were stanley tool boxes from home depot and stackable) each box had one battery and was wired with quick connects on the out side of the box. the control box could connected to one box or all of them. i like the idea because if you wanted you could make the units bigger or just swap batteries in and out of the kit. the reason for the seperate boxes was the fact the batteries are so heavy, each of the battery boxes weighs about 70 pounds so separating the batteries into individual boxes makes the kit easier to carry for one person. *** soon as i find the link ill post it for you.

 

[4x4mike]

That would be great. Thank you.

 

[k9lestat]

http://www.prepperlink.com/index.php/prepare/energy/item/110-lmsps large set up but you will see it is easily adaptable. i was thinking a of a smaller type set up with the smaller atv style batteries

 

[k9lestat]

im looking at taking my ham test. i ordered a cheap handheld to start with, but i know im going to want a mobile unit. bang for the buck and simplicity wise what would recommend for a mobile unit and antenna?

 

[4x4mike]

For a mobile and 2m mono band you can't go wrong with a Yaseu 1900 or 2900. They replaced the 1800 & 2800 which are about the same thing. A simple mag mount 2m antenna or NMO 1/4 is all you need. Search my user name for my setups and antenna questions similar to yours.

 

[k9lestat]

thank you i will.

 

[madmax718]

I could not see you using more than 200-300 watts of power per day for the ham radio. As a general rule, the slower the discharge rate, the more avaliable power. IN short, if you drain the battery using a high drain device (say a 1000watt inverter for a hair dryer) for 1 hour, will use more of the power than a 100 watt inverter for 10 hours.

Generally, Discharging down to 50% of capacity is a good trade off between battery life. Most of the "experts" say an occasional discharge down to 80% is ok, but don't do it too often. And discharging below 50% starts to shorten battery life.

Id work on getting a bit more solar- but if this is a non mobile unit, see if wind is a possibilty as well. THey have combination charge controllers that can do both solar and wind. Small wind turbines can generate a heck of a lot of energy.

 

[4x4mike]

Thanks. I agree on the slow discharge versus fast and yes most of my use will be slower than faster. This little unit would be put into play in a power outage though. The plan would be to run 12v LED lights and possibly 120v AC LED lights in the house on top of charging and maybe running a router for internet if it's available. If the situation was longer I'd change out the battery with one from one of our vehicles so the stored capacity shouldn't be too much of an issue.

One other question that has been in my mind is distance between the panel and the battery/controller. I'm looking at getting 2 panels, one that is mounted to the house and another that will be used for mobile. General practice would be to use one at a time but if need be hook both up to handle the demand. If I'm happy with my first build I may build another 'home' version and use stick to that panel.

How far is too long to have between components? Is it better to have the controller near the panel or the battery? Max distance is less than 15 feet but I wasn't sure if that's pushing the limits. Voltage drop info and what not doesn't seem as available for this stuff yet.