Deep cycle batteries

robotland · Post by **robotland** » Fri Jul 30, 2004 11:17 am

Listen to the Cap'n, he is wise of "current events"......

For stowing your batteries- If you go with regular-sized deep cycle then finding a box is no problem. If you go smaller, like I did, I've found that heavy plastic ammo boxes of the kind made for blackpowder enthusiasts and handloaders can be fitted out as battery boxes by adding blocks to keep the cells from sliding around loose, boring several vents and, if you want to get fancy, adding a covered port with either a connector or cord and a power switch. (Unnecessary for hardwired vehicle use, but great for portable camp power.) A BIG box or auto footlocker would also accomodate a converter or inverter.
I found a great little charge indicator/12V outlet splitter at a flea market for four bucks- Digital voltage indicator, H/M/L (High/Medium/Low) charge lights- Handy! One downside- cheapo cap on the end where it plugs into a 12V receptacle has crappy threads, and came off in the socket! Half-hour of @#!! around to get the @#!! thing out. Took the @#!! plug off, and hardwired it. Works fine. Still worth the four clams.

jbelson · Post by **jbelson** » Fri Jul 30, 2004 11:59 am

FYI, this is a pop-up tent trailer. It's wired inside for power. Has dome lights, inverter, an elec. outlet. It was designed for campsites w/ hook-ups. I cant have the tow vehicle attached (sides of trailer pop out), and dont want to. The batteries will be sitting outside on a tray that is attached to the frame, less than 3' from the inverter tingy. Will probably go with the 2 deep cycle 6volts.
Now, for my general knowledge: Do I wire the 2 batteries together + to+ and - to -, then wire one of the batteries to the inverter?
I Need to know some basics. It seems like a pretty simple thing as I've seen a lot of these type of trailers w/ batteries.

Captain Goddammit · Post by **Captain Goddammit** » Fri Jul 30, 2004 12:11 pm

Wire them "in series", that is, hook your - camper power to one battery's - terminal, that battery's + to the other battery's -, and your camper's + power wire to the other battery's +.

Also, that is an INVERTER, and not a CONVERTER you're looking at, right?
I ask because trailers always have converters, rarely if ever come with inverters, although they can be added later.

jbelson · Post by **jbelson** » Fri Jul 30, 2004 12:15 pm

It probably is a converter. So basically the wiring is in a big loop?

For battery charging, would you hook the aligator clips to one battery to charge both, or do both need to be done seperately?

Captain Goddammit · Post by **Captain Goddammit** » Fri Jul 30, 2004 12:25 pm

If they are 2 6-volt batteries wired in a loop, "in series", hook the charger (presumably a 12-volt charger or 12-volt power from your tow vehicle) to the same place as your camper power wires; the negative of one battery, and the positive of the other battery. (the remaining positive of the first battery is hooked straight to the leftover negative of the second).

It's just like when you stack 2 (or more) flashlight batteries into a flashlight... the + of the bottom battery touches the - of the next one up, and the light is powered by the remaining top and bottom terminals, at a voltage equal to the sum of each battery (2 1.5-volt flashlight batteries stacked in series = 3 volts)

Captain Goddammit · Post by **Captain Goddammit** » Fri Jul 30, 2004 12:27 pm

(and you'll be charging both simultaneously)

jbelson · Post by **jbelson** » Fri Jul 30, 2004 12:48 pm

Captain...YOU THE MAN.

I think I 'get it' a lot more now.

Thanks.

Bob A · Post by **Bob A** » Fri Jul 30, 2004 3:09 pm

jbelson wrote:It probably is a converter.

You will need to figure this out since the converter is not what you want. it will take house current (120v ac and turns it into 12dc for the dc stuff in your camper. You won't have any AC out in BRC.

You want to turn the 12v dc into 120v ac to run normal house plug homestuff. (Inverter)

Actually do you need AC just having the batteries running all your DC stuff directly would be the easiest thing? If oyu do need Ac and have a converter you can pick up a c heap inverter for $30 - $50 depending on what size you want.

Bob A

burningflyer · Post by **burningflyer** » Sat Jul 31, 2004 8:39 am

This may be of help

http://www.ccis.com/home/mnemeth/12volt/12volt.htm

or this

http://www.ae-zone.org/

MrChevere · Post by **MrChevere** » Sun Aug 01, 2004 9:06 pm

I have a small trailer with a single 12V "Type 27" deep cycle lead acid battery. I was able to run a car CD player/radio with amplified subwoofer minimal lights and occasional fan for the week usiing a 5 watt solar panel. I was pretty low on juice by Saturday, but just hooking it up to my tow vehicle and running the engine for 1/2 hour got it back up.

Using a car to charge a battery isn't real eco friendly so this year I have a 50 watt panel. I have tested it on a couple of outings and found that I can run my lights and stereo for several hours and the next morning my battery is topped off completely by the solar panel by 10:00 AM.

There is a lot of info on the sites mentioned in earlier posts, some of which I had already been to. (Phred's is the best, IMO) They will tell you how to precisely calculate your usage and battery requirements. It's all scientific and dangerous but just get more than you think you'll need of everything and you'll be fine. If you're underpowerd it's no big deal unless you rely on electricity to power a respirator or some other life saving electrical device.

Lot's of mention of Honda generators. My brother sells generators and recommends the Yamaha. Slightly cheaper, better built and spare parts are less expensive. They are also a teeny bit quierter according to the specs on the websites. I have a Yamaha 1000. I bought it during an extended power outage but have never actually used it other than the time I hooked it up to my computer and fax machine for a test run and starting it once a month to make sure it still works

jbelson · Post by **jbelson** » Mon Aug 02, 2004 9:56 am

After all this, I might end up going with the generator. I figure it will cost only a little bit more than rigging the whole trailer with battery power that will last the week, plus I'll be able to plug other things in. It was turning into 2 batteries, welding a battery holding plate on the frame, moving my propane holder, securing them, possibly battery box's, wiring to the converter, adding an inverter. Or I could just buy 1 thing.

Bob A · Post by **Bob A** » Mon Aug 02, 2004 11:09 am

jbelson wrote:After all this, I might end up going with the generator. I figure it will cost only a little bit more than rigging the whole trailer with battery power that will last the week, plus I'll be able to plug other things in. It was turning into 2 batteries, welding a battery holding plate on the frame, moving my propane holder, securing them, possibly battery box's, wiring to the converter, adding an inverter. Or I could just buy 1 thing.

The only down side of that route is you will need to run the genny whenever you want power even if it is just your radio or shaver. Its not very efficent use and there will be the noise and the amount of gas you will go through if you run it 8 hours each night. If you put a couple of batteries to it, even if you just leave them under the camper as a temp setup while there; you will be able to run stuff without turning the genny on and then just fire it up for an hour or so every few days or when you run your big stuff.
forget tieing it all into your exsiting camper time is getting tight just run a few extension cords.

Bob A

Tancorix · Post by **Tancorix** » Mon Aug 02, 2004 11:17 am

If you buy a Honda EU Series, check out Captain Goddammit's extended runtime fuel system modification. (Search for it, it's on the eplaya)

Also shop around for the Honda and Yamaha generators. Anything over $1010 for a Honda EU2000i is a rip. There's a fastener company in Reno that sells gennys at the cheapest prices I've found...if you searched for such a company I'm sure you could find it.

I have the genny, and I have two deep cell batteries and a 400 watt inverter for small needs. The inverter was $30 at Sam's Club, the deep cell batteries were purchased used for $20 a pop. The genny can also run a small battery charger and comes with it's own 10 amp charger if I don't mind the wait. With that setup I can do about anything power related I need to do.

jbelson · Post by **jbelson** » Mon Aug 02, 2004 11:23 am

Okay, so if I do a battery, it will power pretty much just my dome lights in the rig. But Will it run other things that I plug into the outlet? I have a Converter, do I need to get an inverter to go between the battery and the converter to get power from it? I'm thinking I might end up bringing a cheap home stereo that plugs into a regular outlet. That would be my main power draw.

I dont know what to think anymore.

jbelson · Post by **jbelson** » Mon Aug 02, 2004 1:51 pm

GEEEZ.
This is what I'm going with. A large deep cycle battery (12v) thats hooked to an inverter in wich I plug the trailer into to run power thru the converter. I bought a large solar panel to recharge the battery. Under $200 total. I'm not gonna have large draws off of the power so I should be fine.
Instead of using any kind of string lights around camp, I bought a bunch of the round paper lanterns that I'll put glow sticks in. Those should look like planets hanging around my camp.

Captain Goddammit · Post by **Captain Goddammit** » Mon Aug 02, 2004 2:26 pm

This is the external fuel feed setup for Honda generators, which, by the way, have a huge advantage over Yamahas; you can connect 2 or more EU-series Hondas together to handle larger loads. No other unit will do that.

http://ilynne.com/captaingoddammit/

Bob A · Post by **Bob A** » Mon Aug 02, 2004 8:54 pm

jbelson wrote:GEEEZ.
This is what I'm going with. A large deep cycle battery (12v) thats hooked to an inverter in wich I plug the trailer into to run power thru the converter. I bought a large solar panel to recharge the battery. Under $200 total. I'm not gonna have large draws off of the power so I should be fine.
Instead of using any kind of string lights around camp, I bought a bunch of the round paper lanterns that I'll put glow sticks in. Those should look like planets hanging around my camp.

Ok you almost have it there.

Battery Fine, Inverter fine (to run any ac stuff), Solar panel ok. You should have a regulator to prevent over charging of the battery from the panel or be prepared to watch it and unplug when full. Regulators are pretty cheap. Some panels include regulators. They also help to prevent back charge, at night. Which is once its dark the power starts to run out of the battery and back to the solar panels.

The converter you do not need. The converter turns Ac to dc to run the 12v lights in the camper. So the way your suggesting is battery > inverter (to make ac) > then plug converter into ac to make DC. The battery already has the dc you want for the dome lights. Just run a wire right from the battery to the hitch cable, make an adapter cable to grab the hot line that usually goes to the cars battery. The inverter is only about %85 percent efficient and the converter is probably the same so you are wasting a lot of power that way.

So you would have 3 things connected to your battery.
1. The solar panels
2. The inverter for ac loads
3. Your dc loads (wire to trailer for dc lights or and other dc stuff.

Leave the converter out of the picture. That is for use when at a RV park and you have Ac power from them. It lets you run your DC stuff with no battery.

Bob A

Captain Goddammit · Post by **Captain Goddammit** » Mon Aug 02, 2004 9:05 pm

Second that, perfectly stated.

jbelson · Post by **jbelson** » Tue Aug 03, 2004 10:40 am

The converter is built into the camper, it came with it. What the plan was, since the camper was wired already through the converter (2 outlets), was to just plug the camper into the inverter (as though I was a a site w/ hookups), so I could use those outlets. Maybe run another extension cord off the inverter for the outside. I got a 400w (mas 800watt) inverter.

The battery is a deep cycle marine type. 210 rc and 125 amp hours. CCA @0 degrees is 675, @ 32degrees its 850. How does that sound for battery power?

Captain Goddammit · Post by **Captain Goddammit** » Tue Aug 03, 2004 4:36 pm

What Bob A was telling you was right on. Your plan to plug the camper into the inverter as if at a campground with shorepower will work, but not as well as just hooking the camper's 12 volt input directly to the battery.
The inverter is only around 85% efficient at transforming power, you will lose about 15%, mostly in the form of heat. The converter is also not more than around 85% efficient at turning the 120VAC from the inverter back into the 12VDC you already had to start with. Just hook up straight to the battery. Then, also connect your inverter to the battery and only use it to power things that require 120 volt AC power.

Bob A · Post by **Bob A** » Tue Aug 03, 2004 9:45 pm

jbelson wrote: since the camper was wired already through the converter (2 outlets),

Wait when you say two outlets, are you talking cigarette type 12v or 120v house type plugs.

If it is the 120v plugs then that is not a converter you have but an inverter. The converter would not be connected to house plugs it would go to either car 12v plugs or 12v car type lights.

If it is a converter and you do have house plugs then they are not connected but they are just on the same shore plug. You can plug your camper shore cable into the inverter you bought leave the converter turned off, it must have a switch and run you 12 volts in from the battery to the other dc stuff. There might be two terminals on the converter you could feed power right into the camper if you don't want to use the hitch cable to run the dc to the camper.

As for your battery the only number that means anything for this use is 125 amp hours. You can pull one amp for 125 hours or 10 amps for 12.5 hours etc. Don't let the battery get more than 80% empty and try to keep it not more than 60% for best life.

You want to be as efficient as possible the power will go fast. A 50-watt incandescent bulb will draw 4 amps per hour. A car stereo will draw 1 amp per hour (avg.). So if you use 100 amps from your battery that would only get you 20 hours. If your run 2 lights you will only get 11 hours. Ac stuff you have to multiply by 10. If you have a blender that runs at 1.5 amps ac it will pull 15 amps from the battery if run for an hour, but that would only run for a few minutes so it might only eat an hour of light in that 5 minutes.

So the point of all this is conserve as much as possible. Your 120-watt (about. 7amps) panel will generate about 56 amp hours of power per day for you on avg. So if you use more than that in a 24-hour period you will be in the negative. You should be ok with what you have planned but wasting 15% x 2 might mean you run out in 2 or 3 days and have to leave everything off for a day to get back up.

Bob A

Captain Goddammit · Post by **Captain Goddammit** » Tue Aug 03, 2004 10:01 pm

Many Converters have a 120 VAC plug on the front panel, it's just hooked up to the shorepower input so you have access to 120 VAC inside when you're plugged in somewhere.
Many converters don't have a manual switch (none of mine ever have). They have a relay inside that will automatically switch the converter/battery charger on whenever external shorepower is connected.

So the deal is, hook up the battery to wherever the camper has it's 12-volt input, either wherever the camper battery originally went, or if none, through the trailer plug on the front hitch.

Hook the INVERTER to the battery and get 120 VAC from it for your 120 VAC stuff, but don't plug the trailer's 120 VAC cord into the inverter, you'll waste a lot of power.

jbelson · Post by **jbelson** » Wed Aug 04, 2004 10:31 am

Okay, so now I gotta find how to hook the battery into the converter. The back is sealed up so I got to take a panel off. I did notice that it has a fuse box right next to the converter. It also has a switch that goes from shore/battery.
The thing is that Last night the dome lights went out. So now I have no draw for the 120volt.
I figure I'll have to put a string of x-mas lights on the inside for light (will make for a nice ambiance) which will plug into the house type plug that is in there (no cigarette lighters).

Tiahaar · Post by **Tiahaar** » Wed Aug 04, 2004 11:29 am

Hey jbelson in case Captain G or Bob A are out (excellent resident advisors on this project) and you're working the problem now, here's my bit: those fuses in the converter should be for the 12V systems and near them or under a removable panel close by should be two large screw lugs for feeding in battery + and -. They should be marked as such, also the + is commonly red and the - usually black wire on 12V negative ground systems. (as opposed to 110AC where the black is the load and white is the neutral or common and green the grounded)

Mister Jellyfish Mister · Post by **Mister Jellyfish Mister** » Fri Aug 06, 2004 7:25 am

Does anybody know of a good website calculator to select the right fuses for different 12 volt loads? Cheers!

Captain Goddammit · Post by **Captain Goddammit** » Fri Aug 06, 2004 4:19 pm

You really don't need a calculator, it's very simple. Watts = volts x amps. Use a fuse that is slightly larger than the load.

A 10 amp fuse will allow 120 watts at 12 volts, 120 watts = 12 volts x 10 amps.

You need to know how many amps your load is. You can either add up all the ratings of the stuff you want to power, or if ratings aren't available you can measure your load with an ammeter, or failing that, guess and go a little bigger if it just blows when you turn everything on.
Unless, of course, you're up to using 50-amp fuses for 3 dome lights and they still blow, then start looking for shorts.

jbelson · Post by **jbelson** » Mon Aug 09, 2004 11:43 am

So this weekend I go to pavements end by Clan Destino, good group of people, and try to rig up my battery, And I keep blowing the fuse on the inverter. Everytime I'd touch the negative aligator clip to the battery terminal, there'd be a spark and the fuse would blow. I went thru all 3 fuses it came with in 5 minutes. But when I tested the battery and inverter at home earlier, that didn't happen. I was also screwing the connectors to the battery thru the other screw type terminal.

Any thoughts? Is it just cause I didn't do the connection quick enough?

Bob A · Post by **Bob A** » Mon Aug 09, 2004 7:19 pm

jbelson wrote:So this weekend I go to pavements end by Clan Destino, good group of people, and try to rig up my battery, And I keep blowing the fuse on the inverter. Everytime I'd touch the negative aligator clip to the battery terminal, there'd be a spark and the fuse would blow. I went thru all 3 fuses it came with in 5 minutes. But when I tested the battery and inverter at home earlier, that didn't happen. I was also screwing the connectors to the battery thru the other screw type terminal.

Any thoughts? Is it just cause I didn't do the connection quick enough?

It shouldn't do that! Was the inverter on or off? was anything connected to it on the ac side? Was there any other wires running to it? was it tied to your camper in any way or was it just the battery and inverter? were you connecting it up + to + and - to - ?.

you may just have a bad inverter. Battery was 12 volts right?

bob A

unjonharley · Post by **unjonharley** » Mon Aug 09, 2004 7:37 pm

THis inverter of mine arces when I conect to the battery. I have tried different ways to conect but it arces every time. It don't blow fuses tho. I know it has a capasitor¿ that holds some juice. I just don't care for the arce so now I leave it in line all the time. Just turned off.

Bob A · Post by **Bob A** » Mon Aug 09, 2004 8:16 pm

I think these things arc all the time. I had reall rfun when I made the final connection from the 4 golf cart batteries to the inverter big spark. I think it is because they are never completly off electrically speaking.

The part I meant when "I said it shouldn't do that" was blow the fuse when it arcs. That would be from pulling to much power all at once or reversing the wires someplace, or a dead short to ground.

Bob A

Deep cycle batteries

12 volt info

Fuses