Charging my RV battery

If the alternator was loafing, the tacoma's would be CHARGED, not nearlý dead.

 

The rv battery is dead, truck battery is 90%. Alternator floats at 13.3- 13.4 volts. Occasionally jumping to 14.2v when it senses a heavy load. Trust me, the alternator is capable, it`s just not set up to run a fridge, and charge a deep cycle battery.
The problem I am having is common with RV`s, it`s just a little worse than some other vehicles, because the system voltage is maintained quite low, likely to prolong the starting battery`s life.

 

The inverter is only used when stopped, not when towing, it does not work to provide charging voltage from 2 sources, on the same (rv) battery. Also, the truck needs to idle to generate the power to charge the rv battery, as it would wreck the truck battery to draw it down further than 50%. Hence the on one hour, off one hour. In other words, modding the inverter would make no difference, as it puts out the full 400w with the truck on or off. In fact, the power is cleaner with the truck off.
And idleing the truck costs about $1.35/hour.

 

So did my 2009, maybe mine is not working right? Strange. I watched during the whole trip, 13.3v (scangauge) was the norm. I can`t recall ever seeing my 2009 at any less than 13.7v. Thanks for the info, I will ask the dealer, next time I take it in.
13.9v would provide a 60-70% charge, that would be all I would expect.
FWIW - voltage drop is from alternator to harness is .8 volt when 15 amps is flowing throught the 7 pin, which meant I was only getting 12.5 volts at the rv battery. It was just enough to keep the fridge happy.

 

I have experience with rv's just not on tacomas

Missed the part about the vehicle batt being fine. If I were charging a second battery which was dissimilar from the others, I would invest in a small, lightweight, quiet generator. Getting stuck in the middle of nowhere with a dead alternator is no fun.
A second alternator running to the deep cycle battery is one option.
Another point is that alternators are for maintaining a battery's charge, not for charging a dead one.

 

With the towing package, it has a larger alternator, with a factory charge line, as marked on the 7 pin. It is there to charge the rv.
But that is why I bought the dc to dc booster, It will allow me to charge from either the alternator, or truck battery, as I have just done for the last 2 weeks, only I should arrive will a full battery, and have to spend less time charging at the site. And this device draws no more power than the inverter on the truck, so it is within the capabilities of the truck.
Chris4X4 mentioned my truck seems to run a lower voltage, that might be an issue as well.

 

Not sure if anyone asked this yet but all RV refrigerators run on propane with 12v/110v as secondary power sources. When I dry camp, I'm on propane.

 

I run propane as well when stopped. When travelling, it blows out the flame. The newer type of fridge that my RV has has the full power 120 watt/12v element, so it cools very well when travelling.
As for the dc to dc converter; I will permanently mount it on the rv spliced in between the 12v plug on th 7 pin, and the rest of the electrical system on my rv. I should get a good charge all the time.
FWIW - the alternator on the Taco is a high output unit, it simultaneously charges the truck battery, while running the inverter full power.

 

Last night a buddy of mine checked his 2010 Taco......His reads a steady 14.1 volts. Maybe the larger problem is mine runs 13.3ish.
Off to the stealership.........

 

@ isthatahemi -

so i found this thread while looking up tow wiring information on my truck. i find it interesting that you post a topic, request advice and help from other users, and do nothing but shoot down all advice and ideas that you are given and continue to contest that your you are going to do it your own way...why the hell would you even post a question on a forum?

please, for the sake of everyone else that may come across your postings/questions, just write that all you seek is someone to agree with you in your whiny signature.

thanks.

 

Nice first post.....
I was looking for things I haven't thought of. The ideas given were good, but in order to keep things moving, I explained to the posters why the idea they offered were not the issue at hand. I was basically doubting that on top of all the other issues my alternator was screwed. But it turns out that my truck puts out lower voltage than others.
But you seem like a real smart guy, what were you adding here, BTW?

 

Reading through the differrent post, I have a 3-way refrigerator and with my Hi-lo TT lowered for towing it closes off the gas exhaust flue so I have to run the refrigerator on 12 volts. It pulls 12 amps on 12volts, with the undersized charge line on Toyota tow package, I was running down my house batteries on my TT while towing. I ran a 30amp circuit breaker off the att., then ran 10 gauge wire to the trailer plug. I had to change the 7-pin connector to an aftermarket trailer plug to use the thicker gauge wire and upgraded the trailer cord. I next upgraded the TT batteries, I wanted more power! A 12volt has 55amp hours, I switched to 2-6volt golf cart batteries wired in series to get 12volts and I ended up with 235amp hours. Next I added a 33watt solar panel on the TT to help keep the batteries topped off ( I know I would at least 100watts to charge my battery set-up) when the trailer in stored. Now I have no problems dry camping.