Boondocking and charging with Toyota factory inverter

Ok to use both for the first 30 minutes to speed up the bulk charge.

BFL,
Yeah, if the goal was to reach 90% SOC, a stand alone charger may win the day over jumper cables. Like you state, constant amps is always more power available. Having the option of just jumper cables is still not a bad way to get reasonable charge back into a depleted jar.

Looks as if we have lost the OP. Sad when that happens.

westend wrote:
BFL,
Are you sure about this? I used to do a fair bit of vehicle recovery where sending power to the inoperable vehicle was the goal. When I had the battery charging recovery unit (220 amp alternators), there was nothing that could beat it. Even a set of jumper cables allow a good bit of power into a discharged battery through a 120-130 amp alternator. It would be fulfilling to see actual measurements of the power transferred between the two options over time.

I was careful to say that the inverter- powered charger had to do at least the same initial charging amps as the jumper method.

It is possible that you could restore more AH with fat jumpers and a good alternator than with a small amp smart charger, even though the jumper amps will taper.

I have some data from my old 7-pin /jumper cable trial, but not sure if that is what is wanted. I used the Trimetric as my ammeter.---

First I ran the trailer battery down to 50% so it would be sure to accept whatever amps either method would produce. 105amp alternator.

A. I confirmed the battery would accept 35 amps by trying it with a 35 amp Vector charger. So that means it would do constant 35 in bulk for a time until the battery reached Vabs, then amps would taper.

B. Battery drawn back down from that, and on 7-pin, engine off, amps at trailer-- 0.3

Time 1611-start engine-amps 10.1
1612- amps 8.5
1613-amps 7.5
1615- amps 7.1
1617-amps 6.5

C. Battery drawn down again, and with 12 ft #10 jumpers,
Start--20 amps, then tapering quickly as above 18.1 amps, 17.0, etc

That was with engine idling. Tried a comparison at 2000 revs vs idle:
17.5 amps revving, 17.0 amps idle.

D. Battery back down, and with 25 ft #1 cu-al jumpers
Start 35 amps and immediate tapering same as above except with more amps.

So---the 35 amp Vector would beat the fatter jumpers starting at 35 amps because no initial tapering with the Vector.

However- with even fatter/shorter all copper jumpers, it might have kicked off at higher than 35 amps so then you would need to run a proper AH restored in same time contest, which the jumpers might win, despite their tapering amps.

BFL,
Are you sure about this? I used to do a fair bit of vehicle recovery where sending power to the inoperable vehicle was the goal. When I had the battery charging recovery unit (220 amp alternators), there was nothing that could beat it. Even a set of jumper cables allow a good bit of power into a discharged battery through a 120-130 amp alternator. It would be fulfilling to see actual measurements of the power transferred between the two options over time.

Running a smart charger off an inverter is better because the constant amps in the bulk stage beat the tapering amps of the jumper cables by a mile. If the charger amps are higher or equal to the jumper's initially.

It is true you can use a bigger amp charger with a bigger watt inverter, but you hit the wall with what the truck's alternator can do to support its battery with that battery being sucked down by the inverter.

What happens is at some higher amps draw from the inverter, the alternator cannot keep up, and your truck's battery voltage as seen on the dash voltage gauge, starts to slide off and down to the left. That is the wall.

Just where this will happen depends on your truck design. I found with my truck I can run about 55 amps of charger with a 2000w inverter clamped to the battery, but that is about it. ( That was with an alternator that was getting old and later needed replacing. I have not tried it with the replacement alternator to see if it can do better)

I have actually done it a few years ago, with a 35 amp charger and a 1000w inverter, idling the truck for an hour with no issues. (Gas truck)

hinkle_e wrote:
I am currently towing my 2014 Palomino Solaire 209BH with a 2008 Tacoma which is equipped with a factory inverter (plug in the bed) capable of putting out 400 watts. Would I be able to run a battery charger off of this to recharge my house battery while dry camping?

Yes, but you will be limited by that 400W. Also depending on the charger and the inverter, the start up (surge) current of the charger might trip the inverter breaker.

hinkle_e wrote:
If it is possible, would it be more efficient to run the camper charger or a stand alone?

From an energy stand point it would be more efficient. However that s not the whole story.

• Modern vehicle charging system do NOT do a good job of charging a second battery in parallel, especially at the end of a long wire. Large gauge wire, like jumper cables would help a lot, but it would not be the best solution. (I would still carry long jumpers for this as a backup plan.)
• Second, a proper 3 stage charge will do the BEST job of properly charging your house battery. However, it will take HOURS because you are limited by that little inverter.

The best answer is, get a charger that can recharge your battery in a "reasonable" amount of time and then get a bigger inverter to match that charger OR buy a generator.

You could turn the TV around and connect it to trailer battery with jumper cables since you are running engine anyway. It may charge faster!

If you have to run your truck to charge the trailer why not just get a small genset?

I think you would do at least as well with some quality jump cables direct battery to battery.
Get #4 wire minimum.

Otherwise yes you can use the small inverter to power a 10 amp portable and maybe 15 or 20 amp.