Questions about solar and batteries

[westernmaroo]

Hopefully somebody can give me some good advice on solar panels. We dry camp with our Roo 19 Zamp ready a few times a year for a week to 10 days. Currently we use battery power for the refrigerator and that is all. We would like to run lights at night, charge cell phones and have a movie night once in a while in addition to the fridge. From what I have researched solar seems to be our answer to keep the battery charged. Can I get away with an 80 watt Zamp or do I need 120, 160? I know a lot depends on the sun and clouds but what of you folks experienced. Also looking for a deep cycle battery recommendations without breaking the bank. Our Marine EverStart batteries are at the end of their life.

Cheers,
Bob

[Dave Lyon]

Bob, I recently camped for a week without hydro. I have a 100W Coleman solar panel that I bought at Costco. We had sun every day and the battery dropped to 11.5V in the morning and by night it was back up to 12.5- 12.7.

I posted this on another thread and based on comments from another member, I was probably just getting by. I have one battery - a group 31 deep cycle.

If you're doing much boondocking you may want to consider at least a 150W or 200W panel(s). If cost is not a factor you could replace your battery with two 6V Trojan golf cart batteries. At minimum I would replace the battery with a group 31 deep cycle - a true deep cycle not a marine or dual purpose and again, you might want to consider 2 if boondocking a lot.

You'll need an inverter to run your TV as it's 120 V.

My 2 cents. I'm sure you'll get some good advice from others.

[Ilovemywife]

I typically suggest a minimum of two golf cart batteries and 200 watts of solar panels for the most basic functional setup. A third ground panel which can be moved around would be something I'd consider too.

A Victron or trimetric battery monitor is an essential part of any solar system and will let you know your daily power usage and current battery state of charge.

[BigLou80]

I have 6 of these that I take with me when I am going to be dry camping, at some point I plan on installing them in the camper... although they are not cheap

https://www.solarelectricsupply.com/...olar-batteries

I'm not sure where you are but it has to be close by either way ( as western mass isn't that big) most of the sites I hit around here don't have a lot of "sunshine" so I've just stuck to running my Honda 1000 a few hours a day to keep all 6 of those charged up. I can both max air fans the bunk end fans all night lights and the pump as needed and only be a 50% discharge by morning

[RobH063]

I have 4 6V Lifeline Golf Cart Batteries wired in series and parallel. They give me 440 Amp Hours total so effectively I have 220 Amp Hours (not going below 50% battery capacity to maintain battery health). We don't make any attempt to conserve power other than all of our lighting is LED and we can't use our Microwave or AC when Boondocking. On a typical fall day/night, where the refrigerator fan will be running and at night the furnace fan will run, phones will charge, radio will be on all day and evening, We'll consume about 15% of our battery power so close to 65 Amp Hours. If we conserved power at all, we could easily reduce that by 50%. In fact, in May/June when the sun is highest in the sky, our batteries stay above 90% charged all the time. Our charging method is a Zamp 160W suitcase solar setup. We also have a Champion 3100W inverter generator that we sometimes have to use if we have a couple of cloudy days where solar isn't very helpful. As Ilovemywife has suggested, a monitor is essential. We use a Trimetric.

[Flybob]

Everyone's situation is a little different ( more or less power usage and more or less sun) . With this in mind, I would suggest the following..


start with 100 -200 W of panels and two good deep cycle batteries.
Get a good battery usage monitor ( so you will know your usage and replacement capability)
Scrap the Zamp installation it will most likely not meet your final requirements.
Buy a good controller capable of approx twice the capacity you think you need, The incremental cost of the next larger controller is much less than the cost of a new ( higher capacity) controller if you later add panels.

After one or two outings, you should have a good idea of what your actual needs are.

[westernmaroo]

Originally Posted by BigLou80

I have 6 of these that I take with me when I am going to be dry camping, at some point I plan on installing them in the camper... although they are not cheap

https://www.solarelectricsupply.com/...olar-batteries

I'm not sure where you are but it has to be close by either way ( as western mass isn't that big) most of the sites I hit around here don't have a lot of "sunshine" so I've just stuck to running my Honda 1000 a few hours a day to keep all 6 of those charged up. I can both max air fans the bunk end fans all night lights and the pump as needed and only be a 50% discharge by morning

I'm assuming your Honda 1000 is the Honda EU1000i inverter? I know not to "believe everything I read" but the article said the Honda EU1000i could not charge a battery %100 you needed to run a good battery charger to accomplish this?

[westernmaroo]

Originally Posted by RobH063

I have 4 6V Lifeline Golf Cart Batteries wired in series and parallel. They give me 440 Amp Hours total so effectively I have 220 Amp Hours (not going below 50% battery capacity to maintain battery health). We don't make any attempt to conserve power other than all of our lighting is LED and we can't use our Microwave or AC when Boondocking. On a typical fall day/night, where the refrigerator fan will be running and at night the furnace fan will run, phones will charge, radio will be on all day and evening, We'll consume about 15% of our battery power so close to 65 Amp Hours. If we conserved power at all, we could easily reduce that by 50%. In fact, in May/June when the sun is highest in the sky, our batteries stay above 90% charged all the time. Our charging method is a Zamp 160W suitcase solar setup. We also have a Champion 3100W inverter generator that we sometimes have to use if we have a couple of cloudy days where solar isn't very helpful. As Ilovemywife has suggested, a monitor is essential. We use a Trimetric.

Thanks rob and if you boondock in NY it should be close if not the same as us here in the MA. All we will run is lights after dark and the refrigerator. No furnace or fans. Do you thinking the Zamp 120 or 160 would allow us a few hours of conservative lighting and still stay north of 80 - 90% when charged during the day.

[BigLou80]

Originally Posted by westernmaroo

I'm assuming your Honda 1000 is the Honda EU1000i inverter? I know not to "believe everything I read" but the article said the Honda EU1000i could not charge a battery %100 you needed to run a good battery charger to accomplish this?

Totally false, I just plug the entire camper in and let the converter do it's thing and charge the battery. The eu1000i won't run the microwave or the AC but it has Zero issues with the TV and the batteries. In fact the converter doesn't even place enough of a load on it to require full throttle.

Where in Western MA are you ? I'm in South Hadley

[westernmaroo]

Originally Posted by BigLou80

Totally false, I just plug the entire camper in and let the converter do it's thing and charge the battery. The eu1000i won't run the microwave or the AC but it has Zero issues with the TV and the batteries. In fact the converter doesn't even place enough of a load on it to require full throttle.

Where in Western MA are you ? I'm in South Hadley

Great! Thanks for the first hand info, its much appreciated. I'm from Lenox, you're about an hour from here. Most of the time we grab a site with hookups but a few places we enjoy, Tolland MA, Woodford VT and Charleston (Burlingame) RI are dry.

[trees]

Biglou agree with your 1000w generator. I have the Yamaha equivalent and it was a wise purchase. It idles down on low load and extremely quiet. Yes, the converter is powered fully for the bulk charge cycle. The generator is light and can easily throw in TT or back of pickup. No A.C. but interestingly I did buy a cheap $100 5,000 btu window unit. I made a wood bracket to quickly adapt in the emergency window. Just on those terrible hot days wherein one needs relieve in bedroom. Funny, the 1,000w barely knows the A.C. is on. It takes something just over 300w. The Yamaha is rated most efficient on gas. On the low load about a cup of gas a hour. So, all night for a half gallon of gas. I usually just use it to cool the TT off good before sleep.

[lablover]

We have a 2015 Roo and unless things have changed our fridge only runs on propane or shore power. We also have the Zamp port. We bought the 120W suitcase and love it. We have done a lot of dry camping out west and have gone to more remote and often more scenic places that others who prefer full hook ups go.

[RobH063]

Bob, If you stay with your current 12V marine dual purpose battery, you will likely need to use your vehicle on occasion to help keep it charged up. My buddy just went through this with a 100W solar suitcase and one single 12V battery while camping in the Adirondacks. He and his wife are very conservative power users so I was surprised when he told me he had to use his vehicle to help charge the battery. He had too much shade to fully enjoy the benefits of his 100W solar panels. I guess anticipating a less than ideal situation to have solar be at its best while charging would be wise. Whatever you decide, go with the Monocrystalline panels. they are more efficient than the polycrystalline ones. I think if you get two 6V true deep cycle batteries and wire them like in the diagram I've included to make essentially a 12V battery you will be fine. I went with the 160W Zamp because it had an adequate controller and it wasn't much more money that the 120W model. The least expensive 6V Deep cycle battery I've come across is sold at Sams clubs. Here's a link https://www.samsclub.com/sams/durace...lp_product_1_1

[babock]

Assuming using a PWM controller, a 100W panel will give you 5.5A max. If you have 5 equivalent solar hours, that's 22Ah per day per 100W panel. Use that as a guide for solar panels based on how much you need to replenish.

If you have 2 6v golf cart batteries and you want to replenish 105Ah, you need 400 to 500w

You can go on sites to see what equivalent solar hours you get for your location and time of year.

[johntaylor]

Originally Posted by Ilovemywife

I typically suggest a minimum of two golf cart batteries and 200 watts of solar panels for the most basic functional setup. A third ground panel which can be moved around would be something I'd consider too.

A Victron or trimetric battery monitor is an essential part of any solar system and will let you know your daily power usage and current battery state of charge.

Everyone's needs are different. I boondock full time with 2 group 24 marine batteries and a Renogy 100 watt suitcase solar panel. That includes running my laptop for 6 hours on many days. I have only needed to run my generator 3 times so far this year, on occasions when I had multiple days of cloud or rain and the batteries were down to 12.1V. On each occasion, I ran a 25A forced charge for one hour from my battery charger.

I have a 12 volt display that tells me from one morning to the next whether I am keeping up with the charge. Most mornings it says 12.5V, which tells me I'm good to go. If it says 12.4V in the morning, I know I'm down a little. It doesn't matter that it isn't telling me exactly what the state of the battery is.