Building a battery generator vs. buying Goal Zero Yeti

[outdoornate65]

Last week I posted about using non proprietary solar panels with a GZ Yeti 400. I appreciate the responses I've gotten on that thread.

As I look at the specs for the Yeti 400, I'm concerned about the Ah capacity of that unit (33Ah) with regards to demands of running my new fridge (Engel MT 35).

Wondering if building a stand-alone system is a better answer for my 12V needs.

Here's what I have cooking:

Living in sunny CO. Trips are usually 4-5 days.

2008 Toyota 4-Runner with no aux battery. I have room under a sleep platform for battery and components.

Electrical needs: Med size fridge and a few LED lights. Charging phones/iPad via USB port

Power in: 100w Renogy Solar panel. Battery Tender while at home. **wondering if I can get away with not running power from my truck's alternator.

Proposed system: 100w solar panel, 100Ah deep cycle battery, solar controller, inverter(???) 12V/USB ports for charging.

I appreciate thoughts from folks that have built a similar system.

GZ is nice due to it's "plug and play" simplicity but I'm concerned about battery capacity related to cost of the unit.

Welcome any advice.....

Nate

 

[john61ct]

Yes, personally 200AH would be minimum bank size for me to run even an efficient 12V fridge.

Unless I was driving all day or firing up a genny at will.

To supply power mostly from solar, 300-400W unless always sunny at the equator.

A portable system would be quite unwieldy, better mounted in/to the vehicle.

Obviously the bigger Yeti system comes closer, but just the bank part is 100 lbs.

And please let's not dignify that IMO silly use for the term "generator". Panels, portable power pack. . .

 

[jonyjoe101]

build your own is the way to go and a lot cheaper. I use to run a fridge 24/7 months at a time with a 120 watt panel and a 75ah agm battery.
But if you will encounter cloudy weather the larger the battery, the longer you can go with charging the battery. 100 ah sounds like a good compromise and weighs about 70 pounds.
What you plan on running is what I was running, the most power hungry on my setup was my roadpro lunch bucket cooker (11 amps) I only ran that when the sun was out.
For your 100 watt panel all you need is a cheap 10 amp pwm solar controller (less than 20 dollars) , mppt won't give you any extra amps from a low voltage panel. With 100 watts you will get about 5 to 6 amps in the best conditions, with my 120 watt panel I maxed out at 7 amps but was mostly at 6 amps.
For connectors I would recommend the xt60, they can handle up to 60 amps, they are easy to connect, its all I use. You can buy 25 pairs for less than 15 dollars. Only drawback is you have to solder the wires to them.
Also get a 90 volt 30 amp combo meter (20 dollars) and you can connect it between the controller and battery, its large LED shows amps/voltage going into battery. LED meters you can read in daylight and also night time, I leave them on all night as a night light, the power use is insignificant.
I have a 200 watt inverter, its all I ever needed, get the smallest one you think you will need. If the most you plan on using is 100 watts, it would be wasting energy to get a 1000 watt inverter.

I moved on to lithium but the batterypacks I made, I can just substitute an agm in there and I would be good to go.

Here's a picture of my latest creation, its a 110 ah 12.8 volt lifepo4 battery pack. I enclosed it inside a grp34 plastic battery container (used to hold my kinetik kh2000 102 ah agm). On the left side shows battery voltage on the right LED it shows the balance voltage of each roll of cells. You can see two xt60 connectors on the back end, that where I connect the controller in/ and power out. The battery inside has it's on fuses. The power out goes to a fusebox where everything connects. Weighs about 30 pounds.


This is my own version of a portable 11.1 volt lithium battery pack, the goal zero lithium400 is 39ah and costs 700 dollars. This one I built is 65ah and I just used an old jumppack as a container. Thats the combo meter on the front.

 

[snowblind]

Here's what I have cooking:

2008 Toyota 4-Runner with no aux battery. I have room under a sleep platform for battery and components.

Electrical needs: Med size fridge and a few LED lights. Charging phones/iPad via USB port

Power in: 100w Renogy Solar panel. Battery Tender while at home. **wondering if I can get away with not running power from my truck's alternator.

Proposed system: 100w solar panel, 100Ah deep cycle battery, solar controller, inverter(???) 12V/USB ports for charging.

I appreciate thoughts from folks that have built a similar system.

GZ is nice due to it's "plug and play" simplicity but I'm concerned about battery capacity related to cost of the unit.

Welcome any advice.....

Nate

Hey Nate.

I have dual batteries AND a GZ400. A few thoughts.

If you want to avoid charging from the vehicle the Yeti 400 is too small for 4-5 days. You could maybe make it but it would be worrying.

If you charge while you're driving you will arrive at full juice and you can set the fridge colder during the drive. This makes for less worry if you get randomly delayed or can't set up solar for some reason.

Even though you're not permanently wiring to your vehicle I would use a charge controller that allows input from the vehicle in addition to the input from solar. This allows your fridge battery to charge from the vehicle but eliminates most of the complexity of running two batteries. This CTEK one is expensive but it would do the job https://www.amazon.com/CTEK-56-677-Automatic-Battery-Charger/dp/B005LBCVL4

Keep your solar panels mobile and get long cables. It can make a big difference if you park in the shade and put the panels out in the bright sun.

I love my GZ lights that daisy chain with wires but I could probably get rechargeable lights (with no wires) for about the same money.

Having the lights and the USB charging tied the vehicle can be a pain. When camping I regularly run the fridge of the truck battery and move the Yeti to the center of camp for lights and charging.

USB charging and lights can be handled very well by the small, portable litho battery packs like GZ Sherpa and Venture. I would not make USB/lights a primary goal for this project.

There is lot about the GZ400 that isn't perfect. At the same time it works pretty good if you play to it's strengths. Yeti is currently $459msrp + $100 for an extra battery. That gives you 66Ah, a multi-source capable charge controller, and all the outputs for $600. I honestly don't know how that compares to a system you can build but I'm guessing the Yeti will be 10-20% more.


Matt

 

[devero4]

I've been running my Engel 45 solely off of a house battery/solar configuration for the last 3 months. Using a 100w Renogy panel, 20 Amp PWM controller, and 55ah Marine/RV Deka AGM. This has suited me very well with the Texas sun. But the only loads I'm running are the fridge, and charging Baofeng batteries and cell phone. The most I have ran the fridge off of this setup has been 3 1/2 days. The battery never slipped under 12.3 volts. I have also found that my battery can come back to a 13.6 float charge after 1 full sunny day with no loads on it. I think as long as the amps of your load don't exceed the amps going back into the battery you should be okay. But I dont have much experience with inverters. Here is a link to a thread that helped me out A LOT, and also has pictures of my setup on page 3.
http://forum.expeditionportal.com/threads/171723-AGM-vs-Lead-Acid-for-solar-(in-2017)/page3

 

[devero4]

I run a permanent solar system. I enjoy the "set it and forget it" point to it. But Sometimes I have to park in the direct sunlight, which can suck if it's super hot out. I've learned that windshield solar screens and cracked windows help a ton.