Batt for trailer

[anthony1]

I've been lurking around for a while. Lots of great info here.
I'm building a trailer for camping and mild 4wheeling. Mainly, just park at a base camp then wheel during the day.

Here's my project.

This is the deep cycle batt I got from local batt shop....they do nothing but batt. It's 3 months old. I got it for $95.00. I've seen these batt on the greyhound buss before.

My question is will this Harborfreight solar charger work ok with the batt for a few days of camping?

http://www.harborfreight.com/cpi/ctaf/displayitem.taf?Itemnumber=96418

I'm using it for 12 volts lights and CPAP machine at night. I was able to run the CPAP machine with a small 140watt inverter with a red top for two nights before.

 

[elcoyote]

You need to figure out how many amps per day you will be using. You also need to know how many reserve amps your deep cycle battery is. You can only count on using 50-80% of the reserve amps. The 15 watt panel you showed the link to will make little more than 6 amps per day.

Here is some info from our site that may help you:

Solar Panels

A solar panel can make a lot of sense for remote base camps. Instead of simply listing different sizes and prices of solar panels, at Adventure Trailers, we prefer to have a consult with you about what you plan to run and how large a system you will need. Often the easiest and least expensive option is to simply double up on your batteries, other times, a solar panel will do the trick and others a generator is the only solution. Our goal is to see to it that you get a system sized correctly for you.

Most commonly where a trailer is being base camped for a week or more, running a few efficient lights, a fridge and a lap top periodically, we find an 80 watt panel in combination with a Group 31 battery and solar controller we can keep the beer cold and the lights on. Call us to help you calculate your energy needs.

Tips for Evaluating 12 Volt Power Requirements

In the same way that we plan our trips revolving around our MPG and miles per tank, we need to do the same for calculating our auxiliary electrical needs. It’s really quite simple: The key is Ohms law. It is a basic equation that can be read a few different ways depending upon what number you need to crunch:

Volts x Amps = Watts
Watts ÷ Amps = Volts
Watts ÷ Volts = Amps

Let’s say you want to know how many Amps an ARB 13Watt, 12V fluorescent light is going to consume per hour. Your answer is 13 Watts ÷ 12 Volts = 1.08 Amps per hour of usage.

Understanding Deep Cycle Battery Basics

The Group 31 Valve Regulated AGM Batteries that we favor in our trailers and vehicle conversions are very stout. A general rule of thumb for calculating available power from these 105 Amp hour batteries is that no more than a 50% discharge (52.5 Amps) will give you the longest battery life and the most cycles. A cycle is each full recharging occurrence. Unfortunately, often we need to discharge beyond this 50%. A deep cycle battery is considering completely discharged when it reaches about 10.5 volts. Below 10.5 volts, most 12 volt appliances stop working. This is approximately 80% (84 Amps)
105 Amp Battery

So here’s the math again. Using our 105 Amp Battery and the ARB 13 Watt, 12V Fluorescent light as an example:

(105 Amps X .80) ÷ (13 watts ÷ 12 Volts) = 77.7 Hours of burn time.

 

[ExpoMike]

My question is will this Harborfreight solar charger work ok with the batt for a few days of camping?

Short answer - No :hehe: :jump:

 

[anthony1]

Thanks for the info.
I'll only be using it for two days. I'll see if it's enough to just recharge it when I come back home. I also plan to add a batt. isolator to charge it while I'm driving. I'll be towing it with this....