Fantastic Fan and Battery Drain

[eamarquardt]

eamarquardt, the three stage chargers due to the electronics can bring a battery up to 90% charge with in a few hours e.g. the Progressive Dynamics charges in boost mode at 14.4 Volts till it gets to that 90% point then lowers it to 13.6 Volts and completes the charge.

Modern battery chargers are better than those of old and do a better job, agreed.

Per:

http://www.solarnavigator.net/battery_charging.htm

http://www.batteryuniversity.com/partone-13.htm

battery charging, done properly, takes longer than most people realize or plan for. Modern chargers can reduce the time but both of these sites provide guidelines and "rules of thumb" regarding charging rates and times and a "few hours" to properly recharge a deeply discharged battery is/seems unrealistic according to these sites.

In many of the posts, re batteries on the forum, folks seem to expect more from lead acid batteries than the batteries are able to deliver and reach a normal life expectency (if they can meet the posters expectations at all). Running a 12 cup coffee pot all day and an air conditioner all night are recent examples of overly optomistic/unrealistic expectations.

You can get more out of a battery than recommended and charge it faster than recommended but you will not get the life out of the battery that you'd get if you discharged and charged at recommended rates. I'm "patheticly cheap" (according to past comments of #1 son) and I try to get the most out of my investments and try and make em last.

All I'm saying is that to get what you want out of a battery you've gotta know your load (both amps and time) and how you're gonna charge it and how long that charging is going to take each day (or whatever) and plan accordingly based upon the specifications of your battery.

Plan ahead, be realistic, and you'll get what you want. Don't plan ahead, push the limits, and you may be disappointed. The biggest thing you can do to make the most of your battery set up is to minimize load. I never ran out of juice on the boat and was away from the dock for 10 days at a time using 100 amp/hour "marine" (read compromise between starting and true really deep cycle) battery as a "house" battery (with two in reserve for starting). I'd bet that not even 5% of teardroppers are using real "deep cycle" batteries (as in golf cart service type) and the 50% depth of discharge and charging rate of 10% of reserve capacity are reasonable "rules of thumb" for most folks systems (but there are four other digits and exceptions to any rule of thumb).

Cheers,

Gus

[Ratkity]

Thanks for all your information Gus!

I'm learning about loads and figure I can drop the Fan vent to medium and my amp usage by nearly half.

I believe my 8725 WFCO panel maintains the battery when plugged into shore power. When my TD is parked, perhaps getting a low wattage solar panel to keep the battery from losing power might be the ticket. I think I'd need an electrician to put in a 30 amp plug outside (no garage, alas - exposed to elements). Which option would be the best?

One of your links say to keep the vent caps on a charging wet cell battery. My dad told me always to loosen the vent caps when charging. Does it depend on how discharged the battery is (how much bubbling will occur)?

Thanks again for your patience with me and my random questions.

Hugs,
Ratkity

[eamarquardt]

Per this web site, you should leave the caps on when charging. Times have changed since your dad learned how to charge batteries so he was probabaly right way back when.

http://www.battery-chargers.com/chargin ... ctions.htm

I looked up your converter and it puts out 25 amps of dc for loads and I assume battery charging. Running the actual converter will take just a few amps at 120 vac. The thirty amp plug is only to cover the ac distribution function of the unit. If you're just going to leave it plugged in to charge your battery when it is sitting at home you don't need to provide it with 30 amp service. You could make or buy an adapter that would allow you to plug it into a standard 110 vac socket. To maintain your battery while at home it might be cheaper to just remove the battery, put inside with an inexpensive float charger on it or leave it in the trailer with an inexpensive float charger on it. I'm sure you can find a small float charger and run an extension cord cheaper than you can hire an electrician to install a 30 amp outlet.

I called the Fantastic Fan factory, spoke with Larry, and the three speed fan uses resistors and their variable fan uses pwm. The low setting on the three speed was 1.3 amps (as I recall) and the low speed on the pwm was .2 amps (I definately remeber that). The point being that a pwm system is much more efficient and betterer (as #1 son once said) when running the fan at slower speeds. At the slowest speeds the varilable/pwm fan uses less than one sixth the power of the resistor model. At high speed they both draw about the same power. Those numbers make an excellent case for pwm if you want to maximize your battery life. You can buy pwm kits and assembled modules for about $25.

Hope this helps.

Cheers,

Gus

[madjack]

Per this web site, you should leave the caps on when charging. Times have changed since your dad learned how to charge batteries so he was probabaly right way back when.

http://www.battery-chargers.com/chargin ... ctions.htm

I looked up your converter and it puts out 25 amps of dc for loads and I assume battery charging. Running the actual converter will take just a few amps at 120 vac. The thirty amp plug is only to cover the ac distribution function of the unit. If you're just going to leave it plugged in to charge your battery when it is sitting at home you don't need to provide it with 30 amp service but it would have to be 240 volts. To maintain your battery while at home it might be cheaper to just remove the battery, put inside with an inexpensive float charger on it or leave it in the trailer with an inexpensive float charger on it. I'm sure you can find a small float charger and run an extension cord cheaper than you can hire an electrician to install a 30 amp outlet.

Hope this helps.

Cheers,

Gus

errr, Gus, why would it have to be 240v and not 120...especially since it is a 120v unit.........

[eamarquardt]

For some reason my computer can't open the spec pdf document on the WFCO web site and I couldn't learn what "flavor" electricity it ran on. Not being intimately familiar with 30 120 volt service (kinda unique to RV service I think) I wrongly figured the 30 amp was 240 volt. I later did a search and learned there is a std 30 120 amp plug, etc and was in the process of editing my post as you were pointing out my error. I stand corrected!

That being said, I see no need to provide 30 amp service to run a battery charger (integral in the WFCO unit) that uses 3 amps or so. I'd make an adapter or something and just plug it into a wall socket at home to keep the battery charged and not push beyond the capaicty of the wall socket.

Cheers,

Gus

[Ratkity]

If I set up a low wattage float charger (2 volts) solar setup, would I need a controller to make sure it didn't overcharge? I saw a couple of low watt solar chargers at Cabala's for fairly cheap.

Thanks again for all your patience!

Hugs,
Ratkity

[eamarquardt]

According to:

http://www.batteryuniversity.com/partone-13.htm

a float charge should be about 40 or so milliamps for a "car battery". A two watt solar charger can put out about 170 milliamps (in bright sunlight and if the rating is to be believed). I'm not an expert but I think connecting a panel w/o a controller to an unattended and unused battery is not a good idea.

I'd save up and buy a good panel and controller so you can use it to supplement your power while camping and keep your battery properly charged when the trailer is not being used. A friend does this on his motorhome with good results.

Cheers,

Gus

[Ratkity]

According to:

I'd save up and buy a good panel and controller so you can use it to supplement your power while camping and keep your battery properly charged when the trailer is not being used. A friend does this on his motorhome with good results.

Cheers,

Gus

I ran a solar calculator and the way it read, I'd have to expend some major $$ (600 or more) and get a big solar panel in order to keep up with power needs. I might have read it wrong, however. (http://www.batterystuff.com/solar-calculator.html). My compromise was to extend battery life by keeping a full charge on the battery and use amperage sparingly during dry camping.

Hugs,
Ratkity

[Shadow Catcher]

There are deals to be had on solar panels from time to time. I picked up our 180W for $300 on eBay, some one had bought it and had not used it. Same with the charge controller a Sunsei for less than $50 bought but not used. I also managed to pick up a new Kipor 2400W industrial generator for $300 for the days the sun does not shine.
One thing to remember too, reduce demand, all of our lights are LED and the case fans us very little juice.

[madjack]

Gus, you are absolutely correct...the WFCO's and such with three stage charging should never draw over an amp or so for battery charging and could be plugged into any standard 120vac receptacle...afterall, if it is outputing 30a worth of DC power, the converter is only drawing 3+ amps of AC power to do so.............

ratkitty...those little solar powered battery maintainers don't need a controller since they don't put out enough power to need one...keep in m ind these units will not put out enough power to keep you up and running while out camping...they are not chargers but maintainers...in other words, they maintain a full charge on an already charged battery...about the least you could get by with for charging while camping is one of the cheapy panels with controllers from Harbor Freight for around 200 bucks for a 45watt panel...this set up will output around 3amps(orso) in good, hard sunlight.........
madjack