MNtundraRet
Bloomington, MN
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Joined: 12/06/2007
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It sounds like you are describing a Interstate 12v starting battery (100 minutes reserve). An Interstate Deep Cycle battery would be in amp-hours (75 AH or 85AH). If your really are using a starting battery, it may be shot by the end of the first season, and you will get little usage time between charges.
Mark
Mark & Jan "Old age & treachery win over youth & enthusiasm"
2003 Fleetwood Jamboree 29
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tafische
Memphis
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Joined: 10/14/2009
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Exact model is an interstate hd24-dp. It is a deep cycle/starting combo. Not the best battery, but it came with the trailer so that is what I have to deal with until I upgrade.
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Mamzerook
Okanagan B.C.
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Jumper cables hooked direct from the TV to the TT battery will charge much faster than through the small vehicle wiring to the converter. A generator with a battery charger is the next best solution. Charging via the 7 blade plug is a very slow process. Most TVs are equipped with at least an 80 amp or better alternator(my 1 ton diesel has a 130 amp) Be sure to keep an eye on the electrolyte levels in the battery tho, as more rapid charging will evaporate water and dry the cells faster.
1995 K3500 Silverado 6.5l TD
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willald
NC
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As already said, charging with the tow vehicle is terribly inefficient, due to how little amperage can go across the small wires going to the trailer.
Of course, depending on what converter your trailer has, you may have similar limitations even when recharging by plugging into A/C (or a generator). Many trailers come with cheap converters, that only put a tiny amount of current to the batteries when recharging.
If you must re-charge with the tow vehicle, you could do so much more efficiently (give the trailer batteries more boost much quicker) by simply running a pair of jumper cables from the tow vehicle's battery to trailer battery while vehicle is running.
Not something I'd suggest making a habit out of for the obvious reasons. But, for an occasional quick re-charging, it can work OK and allow you to charge your batteries fairly quickly, without having to run the tow vehicle for very long.
If you plan to do a lot of camping 'off the grid' without electricity, I would suggest that eventually you look at doing the following:
1. Upgrade batteries to a pair of TRUE deep-cycle 6 volt batteries.
2. Upgrade converter to a good, 3-stage 'smart charging' converter, if you don't already have one
3. Consider getting a small, quiet Generator for charging the batteries.
Will & Angela
2 children that love camping, Stephen & Allison
2003 Ford Excursion V10 4x4 ("No Taxpayers were harmed by the makers of this truck")
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taborekle
Clements, Md
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I did a test once and hooked a amp meter up to a very discharged 12v battery and with the truck running it only charged at a rate of 7 or 8 amps.
The charger in my current RV is a 3 stage and so would very rapidly recharge the battery compared to the TV.
Larry
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Empty Nest, Soon
Southeast Ohio
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tafische wrote:Thanks for the info - good stuff. I realize using the engine is not the most efficient way to charge, but for the few times I might have to go dry - it seems like a good way rather than haul a generator with me (KISS method). I have a 2009 Jayco with an IOTA 45 watt converter. I only have a relatively small Interstate 12volt (100 reserve), so my thought was if I ran low I could run the engine for an hour or so here and there and bump up the charge a little. Just trying to figure of if that is going to do anything for me or if I am wasting my time.
If you’re determined to charge your battery with your truck, you should by all means use jumper cables, not the 7-pin plug. The heavier the jumper cables, the better.
Hook up the jumper cables from the TT battery to your truck battery and leave it for several hours so that the batteries equalize a bit. Then start your truck and let it fast idle for however long.
Remember, the truck’s voltage regulator will see the almost fully-charged truck battery that is in the circuit and will not allow the alternator to put out anything remotely close to 80 or 130 amps. Besides, your battery (probably on the order of 80 amp-hours) will not accept that much charge without shortening its life significantly. For this size/type battery, 15 amps is a good charge rate.
If you want to be able to pump amps in your battery bank faster, you need to upgrade the battery capacity. A good rule of thumb is that you should charge your battery no faster than Capacity times 20 percent. Many sources say that Capacity times 10 percent is a better charge rate for best battery life.
Wayne
Wayne & Michelle
2004 Pioneer 19T4
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smkettner
Southern California
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As said if you insist on charging from the vehicle use some heavy jump cables direct battery to battery with the motor running.
As for using the generator and converter get an IQ Controller for the IOTA ( $25 ) and you will get way way faster charging than your other options. Make sure you have a dual voltage jack on your IOTA to plug the controller in before you buy. It looks like a phone jack.
It still takes time to charge. There is a chemical reaction that must take place so it is not the same as filling your fuel tank. Even with the IQ controller it will take two to four hours to get mostly charged. The last 10% takes an additional four hours so plug in for a time when you get home to be sure you get back to tip top 100%.
* This post was
edited 10/29/09 03:39pm by smkettner *
2001 F150 SuperCrew
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Huntindog
phoenix arizona USA
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My first trailer did not have a convertor. I tried charging by plugging into my TV. I measured the charge at 1-2 amps. I bought a generator with 8.3 amp 12 volt output (along with 3300 watts AC) that 8.3 amps was a huge improvement.
A generator and most any modern convertor will beat charging with the TV by a HUGE margin.
Huntindog
2010 Palomino Sabre 30BHDS
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MNtundraRet
Bloomington, MN
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If you do not wish to spend money on a new converter/charger (multistage version), you can buy a portable multistage charger like my Schumacher SC-12000A Speed Charger which can charge up to a 40 amp-hour rate, or the top of line BD model with a similar rate. Black & Decker purchased Vector a few years ago. BD model is a little cheaper than Schumacher, but is less heavy-duty and slighly behind in newest technology. But for most battery-charging purposes for RV's it should do just fine.
Mark
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rrupert
NW PA (Oil Heritage Region)
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My Toyota Tacoma has a 400 watt inverter built in. I can plug either the trailer or a charger into it and give a quick charge if needed. This seems inefficient because of having to run the engine to use the inverter, but it sure beats paying a pile of money for a generator just to charge the batteries. I can burn allot of gas charging and still not have the expense of a generator. This also works much more efficiently than plugging the pigtail into the truck. The inverter can be used for all kinds 120 volt low wattage applications. With all the inverters that are on the market it would be easy get one to hook up in your TV.
* This post was
edited 10/30/09 07:14am by rrupert *
Joyce and Rich
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