Yet Another Battery Question?

[OC Campers]

I know I've read this info as a post but now when I need it, I can't find it.
 
When dry camping I have a cool and quiete little Honda genorater with drect 12volt leads to recharge my battery, My problem is I don't want to wait until the battery is completely dead befor I recharge the battery.When you read the Voltage off the battery, what reading is for a full battery and when should it be recharged.
 
I am also thinking about installing a battery meter to make checking the battery easy. Anyone got any ideas on this project? I amagine I can buy a meter at JC Whitneys. I know i could just wire this in the lighter socket on my TV and may go that route if doable.
 
Randy

[Diplomat]

Randy,

The guru's will tell you that you need to let the battery rest for a while before checking the voltage to get a true idea of the state of charge.  If Santa were nice enough leave me a generator (or SWMBO would let me buy one!) I suspect I would charge for an hour or so per day depending on how much I thought I had used.  

You might want to look at Bart's 12 Volt Side of Life site and see what he has to say.

[garym053]

I would simply purchase a digital multimeter for $15.00 and test the battery as you use it. The constant reading ones will use a small amount electricity to provide the reading. You could get one and wire in a momentary contact button into it and then just push the button to take a reading!

Battery Charge, after resting:
12.6+ V = 100% charge
12.5 V   =  90%
12.42 V =  80%
12.32 V =  70%
12.2 V =    60%
12.06 V =  50%
11.9 V =   40%
11.75 V = 30%
11.58 V = 20%
11.31 V = 10%
10.50 V = 0%
I have this chart taped on the back of my multimeter. As I have medical equipment that I run through an inverter, I keep a pretty close eye on things and try not to let it get under a 50% charge. I do not use a generator, but carry one or two 12V Deep Cycle Glass Mat Batteries with me, depending on the length of the trip. One battery will run my CPAP for 4 days. I also have a pigtail that plugs into the TV Electrical Socket to charge the battery as we drive and sight see. BUT USE CAUTION with this as the battery needs ventilation, and needs to be fastened down. In my Jeep, that's not a problem and Glass Mat Batteries are not as prone to leaks and fumes as others (Supposedly!)

[tlhdoc]

Here is what I use to check my battery.

http://www.campingworld.com/browse/skus/index.cfm?skunum=19983

[topcat7736]

Randy,

I would just use the generator for power and save the charged battery. Hondas don't have a very long run time on a full tank of gas and you're not going to fully re-charge your battery during their 'on' time anyway.

Another alternative might be to use the battery+generator during "peak" usage periods (to recharge the battery a bit while powering your devices) and just use the battery during the "off peak" hours.

[MtnCamper]

The most efficient way to charge your battery with the Honda, is to use the Honda to power a battery charger. You see the Honda puts out a steady 13.5V all the time.... So you could over cook things  a tad.

As far as a multimeter goes, Harbor Freight had some fairly good ones for $3.99.

[OC Campers]

Thanks, that was exactly the info I was looking for.

Randy

[Steve-o-bud]

Thanks, that was exactly the info I was looking for.

Randy

On a deep cycle battery, you should run it down as low as possible prior to charging it again. Then, you should try to charge it as much as possible. This is what the deep cycle battery is designed for, and will extend its life.

Our Bayside is an older model, with no 12 volt convienience outlet inside the trailer. Instead of going through the hassel of removing the cover off the battery box to measure my voltage, I simply check it at the plug on the trailer wiring harness connector.

Also, I'm thinking about making an "extension cord" for my trailer wiring harness, so that I can obtain power from the tow vehicle in case I have some short duration power need, and the battery is dead. I find it generaly not too convienient to get the truck that close to the trailer, once I have everything situated.

Such was the case this weekend. We were dry camping up at Mohave Narrows with our Indian Princess group in Victorville. I didn't fill the water tank as our water needs were low, and I was using a colapsable water jug. However, I didn't realize that the switch for the demand pump was on, and it ran constantly, for about a day. (foolish me, I heard the noise faintly, but didn't investigate what it was.) Anyway, it ran the battery down pretty low. Hopefully, it didn't damage the pump.

[OC Campers]

Af far as getting a short burst of power from the tow vehicle. My trailer came with a wiring setup that plugs in your tow vehicle accessory socket and the plugs in the trailer wiring. That way in a pinch you can get some power to run the water pump.

The post on the output of the Honda Generator about it putting out 13 volts is interesting. I'll have to check that out, it probably would not be a good way to charge a deep cycle battery. I'd have to disagree on the amopunt of time you get froim this generator on a tank of gas. Last time I used it I ran it 4 hours and still had gas left. The neat thing aboout these 1000 watt Honda generators is they are quiet to run. In a larger federal campground site your neighbors can't even hear the thing running.
 
Thanks for the info
 
Randy

[tlhdoc]

Also, I'm thinking about making an "extension cord" for my trailer wiring harness, so that I can obtain power from the tow vehicle in case I have some short duration power need, and the battery is dead.

I have an extension cord for my PU made by Fleetwood.  It has the Coleman/Fleetwood battery wire connector on one end and a cigarette lighter connection on the other end.

[garym053]

Uuhhh, I think most battery sites will advise you NOT to deep discharge any battery, even a Deep Cycle battery that is sort of made for that! It still shortens their life span!

[MtnCamper]

I run dual grp 27's, and try not to lean on the TV battery at all. My luck it would be dead when I wanted to leave. And BTW, I also run dual grp 24's in the truck, So I do have a bunch of power available.

IIRC my Honda will run between 6 and 8 hours, depending on the load.