15 replies to this topic

[PaulT]

Another way to look at is this. You are pulling into a camping area. Do you park in bright sunlight to fill your batteries or in partial shade because you would like to be cooler for the next few hours.  In bright sunlight, your MPPT charge controller shows you are putting 15 amps into the batteries. In the partial shade location, you are putting in only 2 amps.

 

Now if you know that the battery has enough charge to keep your fridge running overnight & well into the morning, you can take the cooler spot. Conversely, if your battery has only enough to last until 02:00 AM, you would select the sunny spot to put more energy into the battery and get a better night's sleep because you know your food will be safe. 

 

The MPPT charge controller tells you how fast you are storing energy or taking energy out of the battery.  The BMV is the device that tells you how full your electrical tank is so that you can make a better decision.

 

Paul

[Beach]

Paul's post brings up a good point in that you must have a large enough battery bank to supply your needs during times of low or no output from your panel. I get by with a 55 ah single battery, most folks here with a fridge and other accessories running on 12v will be at a minimum 150 ah capacity and on up past 200+ ah. Very important to get a idea of your ah requirement.

[smlobx]

This is a topic that I am woefully under schooled...and one of the reasons this website is so helpful.

 

Having said that, on our recent trip to Alaska we had several days while we crossed Canada that were cloudy and even though our truck was charging our 100 AH BattleBorn battery during the day we found that with having both a built in fridge and a 40 L 12V freezer we were struggling to keep up....We will be adding another 100 AH battery to hopefully extend our range.

 

One thing that did work well for us was the addition of a 100 watt portable solar panel from Overland Solar. When the sun was low, typically in the afternoon, we were able to place the panel on the side of the vehicle and at the right angle to maximize its capability. Highly reccomend..

 

https://overlandsola...0-solar-charger

 

I see they have upgraded their panel to 130 watts..

 

 

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Edited by smlobx, 09 August 2020 - 01:22 PM.

[CougarCouple]

Hello Eyemgh

What is the amp hour rating of the battery you have? Vic’s comment about identification of power usage is important in building a system.
Lots of reading will help understanding what you want to do and how to accomplish it. I’m no expert and we’ve been lucky with our system that ATC built for us. I do feel confident I could put together a solar system now, but that comes from understanding the components and how they work.
Really cool how much knowledge the members on this site have.

Russ



https://www.renogy.com/calculators

Edited by CougarCouple, 09 August 2020 - 02:49 PM.

[Stokeme]

A view from an initial electric newb to now beginner. Itemize your individual Ah drains/day, calculate your total drain/day, ie your Ah’s/day average need. Your chemistry will decide the actual usable Ah from your battery & how best to maintain optimum battery longevity. Other than LiFePo4, the deeper the habitual draw, the shorter your overall battery life. See below:

Shallow Depth of Discharges (DOD) will result in a longer battery life. <50% DOD is recommended
75-80% DOD is the maximum safe discharge for flooded and AGM batteries
Do not discharge flooded batteries >80%. This will damage (or kill) the battery. Recommend operating DOD for flooded batteries is 50% to 75% of capacity

Highly recommend Victron controller, IMO go “Smart“ no matter what controller size chosen. If your usage is really low, particularly if low across the board, you can maybe live w/o a battery monitor. You can roughly get an idea of your battery capacity by looking at the total V of your battery with the Smart controller. V indicates charge. A monitor is definitely best for detailed usage info. Here is a monitor I got my son a few months back, so far so good, @$41. As always, buyer beware.
https://www.amazon.c...uct_top?ie=UTF8

Here is a review by Will Prowse on YouTube, which inadvertently sprang up on my tablet after a topical conversation.
https://youtu.be/E6O76Okmt08

Edited by Stokeme, 10 August 2020 - 04:57 AM.

[eyemgh]

When I said I just bought a Raven, I meant that in a very literal sense. We sealed the deal last week and the shipper picked it up today. The few things that I've been accumulating are sitting in the living room. 

 

It was built in 2018 and configured with the standard single battery that FWC supplied at the time. I'll know more specifics in a few days. I probably should have known that, but regardless, it wouldn't have changed my overall impression of the truck and camper. All I know is that it is prewired for solar with a port on top and on the back, the truck alternator charges both the truck and camper batteries, and there's a separator that keeps the camper from drawing from the truck battery. Will know more soon!

 

Thanks!