Inverter amps question

That's pretty impressive full mosey!

MEXICOWANDERER wrote:

...
Smaller battery banks relied on heavily for inverter duty could really profit from AGM rather than dlooded batteries. The upgrade performance wise, is impressive.

Yep!, that has been my experience.

This past winter while in Quartzsite, AZ, purchased a Magnum 1012 1000W/50A inverter charger. I wanted to shake it down.

I ran a MW and a coffee maker for a total of 30min from a 53lb 79AH AGM with a 1000W PSW inverter/charger. At 9.54 Volts, the inverter invoked its LVD to protect itself from the rise in Amps to maintain the Wattage draw.

The coffee maker was a small Mr. Coffee that uses 600W and the MW is an inverter Panasonic model that uses constant/steady 675W on power setting 4. That represents about a 700W draw or about 70A from the AGM.

This was in the AM and after the AGM had run two(2) Dometic CF-35 12V fridges overnight.

This AGM had just started its 6th year of use.

How sweet it was to recharge the 79AH battery with a 50A multistage charger! That is a puny 62% of battery AH. That is where temperature compensated chargers earn their keep.

Are there any accounts of working a comparable size flooded battery like this?

HTH;
John

Yes. Running your engine will help a lot. But it's noteworthy to keep in mind inverter output will be greatly degraded if the alternator output is being used to recharge depleted batteries rarher than trying to maintain voltage in fully charged batteries. Inverters even small ones eat like a 17-year old. I guess I otter make this point again.

Smaller battery banks relied on heavily for inverter duty could really profit from AGM rather than dlooded batteries. The upgrade performance wise, is impressive.

First consider a pair of GC-2s in place of those G-27s More amp hours, about the same price. and since they are DEEP CYCLE you can use more of the stored power without damage to the battery.

Second: NO, there is absolutly no way on the planet the load will be shared equally between the tow vehicle and the trailer,, the six ga wire is simply not hefty enough, you'd need a wire bigger than your arm to even approach equal sharing and even then you'd not get it.

Yea, when you say "popup camper", everyone will assume a popup tent trailer, unless you had posted in the TC section.

Yes if the #6 is shorter you may get closer to 50 amps. So maybe 40 amps from the group 27s or 20 amps each. This is heavy but reasonable usage.
I had assumed a popup trailer vs a popup TC.

In AZ you may enjoy 100w to 200w of solar to help keep the batteries up.

Thanks for the replies
To be more clear
I have a truck camper in the bed of truck
the 2 rv batts are in camper
I thought with the engine on under hi amp condition
The batts would last longer
The microwave is 700 amp power with 1050 total draw
The inverter will be a 1500 PSW

Hard to say what's pulling amps from where, other than the path of least resistance. Give it a shot.

I was able to run a 1000w inverter clamped to my truck battery with 16" lengths of #1 gauge wires, but only if the load on the inverter was about 600w (a 35amp Vector battery charger)---answer follows how to use that instead of the OP plan which looks dubious.

If the load on the inverter got much more than that 600w the truck's voltage would drop off (needle drooping to the left instead of straight up) but it did ok for over an hour with truck idling (do turn off the climate control! That helps. :( )

You can run a small microwave on an inverter but my Xantrex 1000w inverter only runs the Danby 700w one with the inverter showing "overload" at 1050w, which it can do for five minutes before shutting down to cool off. So you need a bigger inverter than that.

That is with the big enough inverter on a big enough battery bank and wiring to be able run 100amp draws.

Your two 27s could briefly if they start out near full, but the alternator supply to the bank on a long #6 would have to supply an increasing proportion of the 100 amps and IMO would very soon run out of steam where the truck's voltage drops off to its starting battery's voltage, which will then fall, and you are losing. So--

You could do it this way--run the microwave off a big inverter properly wired to the two 27s. AND have another inverter up by the truck battery with a long 120v extension cord back to the battery bank where your 35amp Vector is clamped on. With the truck idling it can support that much load no trouble, same as mine did.

So now the 35amps is helping with the 100amp draw on the 27s leaving the net draw at 65a. So now it all depends on how long will the microwave be on before the 27s get down to 11 volts and the inverter alarm goes off?

I should add the a MH normally has a solenoid (or solid state switch) that allows the alternator to charge the house-batteries and starter battery while the engine is running, but blocks drain from the starting battery when the engine is off. The cable gauge is usually 2 or heavier to allow maximum current from the alternator.

It looks like your trying to do the opposite without the engine running.