Inverter issues in 2012 volve vnl670...Help plz

OK ... can't tell you why they burn out, I think it is because these are cheap inverters that have a short life built in.

1 - make sure there is some fused protection in line with the power cables as close to the batteries as possible, DO NOT use circuit breakers.

2 - get rid of the surge protector, the inverter should have protection on the output of it and it won't help anyway.

3 - DO NOT start the truck with the inverter on. These are cheap inverters no matter what people claim they are. They don't have brown out or spike protection on the input of the inverters and if you start the truck, there is a HUGE spike of voltage that happens so fast that it is almost undetectable. There is a lot of info from the truck and car manufacturers about this issue with radio equipment and one thing that there is special circuitry designed to limit damage.

4 - the fridge may be good for you if you are in a dorm but the truth is they are not made for trucks nor should be used. The best solution is to get a proper fridge that is made for trucks or for expedition (like a Engle fridge) which means it will be 12 volts and have proper voltage protection.

5 - as mentioned cabling is key to this, the bigger the cable, the better but going back to my number two point, get protection as close to the batteries as possible - it is amazing how much heat is created by a shorted cable and how quickly fires start.

6 - going along with number five, make sure that the mechanic installs the wiring RIGHT, this means cutting proper hole sizes, using GROMMETS (or better yet proper feed through connections) and properly securing the wiring so vibration doesn't screw it up and cause a fire (see number two).

Hope this helps.

 

In many cases, you can run brief if your batts are in great condition or AGM. Starter batts just aren't designed for loads like and inverter. When you microwave something you use it for at least 1 min. When you click your starter you crank for at most 10 secs. Normal starter batts loose voltage fast with continued use. If you use a volt meter on while runnign a continuous load it will atart at 14.4 and within 30 seconds it will be down to 12 volts. After you turn the draw off it will recover up to around 14.0. So how "brief" are we talking? Not long enough to heat up your hot pocket.

Now if you have AGM batts that are designed for continued use and long drains, they can suport a 2500 watt inverter. My agm batts can runmy microvawe for 10 or 15 min with truck off with no problem. (havn't tried longer then that.) They still have 900 CCA each and start the truck fine. When i drove a company truck with starter batts my microwave would cut out after 10 sec and start beeping. (same inverter)

 

With nothing on, check the voltage at the batts and then check at the inverter. Do the same while its under load. Also does the inverter display a 3 digget code?

If the voltage is lower at the inverter your wires need to be replaced with bigger ones. While your looking at it, make sure it has a fuse or breaker where it connects to the batt. If not your truck could catch on fire if it ever rubs through the insulation and shorts. I melted a wrench one time by mistake when hooking up my batts. I dropped it as soon as it sparked and it melted the handle before i got a stick to knock it out. (hit the frame with handle while bolting on terminal) 12 volts isn't much, but when you have 4 batts worth of amperage it can be dangerous.

 

I disagree. Primarily because you are basing your statements/data on the inverter operating at full 100% load (2500 watts), which it is not even close, in the OP's scenario.
The OP's actual current draw is only a fraction of the inverter's full load capacity. A 700w - 1000w microwave can be run for ample time (~15-20 mins) with engine running, without needing expensive AGM batteries. And even by your own statement, a 150 amp alternator will provide 1000 ac watts of output (that's very conservative, btw) and will be fine in keeping up with 700-100 watt draw.

Multiple starter batteries, if in good condition, will be just fine in this case. AGMs are better, but just a glorified unnecessary option, in this case.
To reinforce my statements are true, there are thousands of 2500 watt inverters functioning just fine, with the OP's exact "current draw" scenario, running standard batteries, and working great at running microwaves, small fridge's, etc, etc. Plus, I have one myself.

 

What some of you don't know is truck batteries are combo batteries, meaning they are both starting and deep cycle batteries. The problem with AGM batteries is simple - the charging systems are not setup to properly charge the batteries and their life is shorten by it.

 

You just said, it can keep up if the load is not at the full 2500. My point was that the 2500 is over kill since it cant keep up if it has a full load. If a 1500 isnt big enough for what your running getting a bigger inverter wont solve the problem. A 700 watt microwave pulls over 1000 watts dc, but will work fine on a 1500 or 2500 watt inverter assuming the batts can keep up or the engine can. Unless you have great batts though, you will never be able to keep a 2500 powered at max load, so there is no point in getting a 2500 over a 1500. if all your using is 1000 watts then a 1500 is fine. Now, a 1000 DC watt draw on starter batts with engine OFF, may work when they are new, but it will kill them quick. They are not designed for it and will fail prematurely if normally used for loads like that. Best option is only microwave while engine is on OR buy AGM. Agm are not a "glorified unnecessary option" if you pull a lot of power while engine is off and don't want to wreck your starter batts. They arn't even that pricey. I got 4 with 1000 watts hours of storage each for only 119 a piece. I can microwave for 4 hours (but then wont be able to start the truck) or run my 500 watt electric heater (with a thermostat, turns on and off, not continuous) for most of the night. Now agm are a waste if you dont have many high draw items and can runt he truck to cook, but if you want to run a 1500 watt toaster oven, a 1000 watt hot plate, run a tv and laptop, runa fridge, electric heat, fans, etc. AGM will hold up much much better then starter batts. (not all at the same time obviously)

 

If you buy marine deep cycle thats true, Deep cycle designed for trucks like truck voltages and are fine with it. AGM is different then LION. LION batts are the ones that do great with charge and discharge, and are light weight, but don't like being charged without a charge controller and specific voltages. A good truck agm batt will charge at anything from 13-15 volts. Most alternators if working properly put out 14.4. marine ones prefer 12ish for charging and will die early if charged at 14.4 a lot.

Mine have been in my truck for 6 months, so not to long, but they still have just as much run time and CCA as on day one. (just got um tested to make sure I was good to go for the winter.)

 

I used to work int he solar industry, so batts, inverters, dc to ac loss, etc...is my wheel house lol.

 

I've posted enuf on this issue and really don't wanna drag it out, to make it a back & forth between us.
I do find agreement on some of your substance, but also find many where we may not see eye to eye.

Two things that I believe you're overlooking. Duty cycle and efficiency.
An inverter is effectively a power supply. They operate at their greatest efficiency at approx 50% to 65% of their full load capacity, on average.
That is why it's better to run a 2500 watt inverter to power a 1000-1500 watt device, than using a 1500 watt inverter.
Greater efficiency and safer longer duty cycle. Sure a 1500 watt continuous should be able to run a 1500 watt load continuously, but it's operating on the brink of it's duty capacity, making for a much shorter lifespan.