2000 Watt Invertor Issues, Need Help

We're all anxiously awaiting his findings in the panel... at least I am. I'm not even sure he has one. I'm also wondering if he's using an outlet or it's hard-wired.

2oldman wrote:

jrnymn7 wrote:
Have you ever tried running the MW immediately after turning off the charger, while V is dropping, but is still somewhere between charging V and actual V ?

No, but it's not a fair test of batteries, since that situation is not all that frequent.

True, but it is the situation presented to us. The OP agreed he should re-do the test, after surface charge has been discharged. In fact, he actually did... and the result was the unit shut down...just too many questions and very few facts. But it does appear the inverter part of the unit is on its way out; barring some low voltage setpoint issues.

He also needs to compare batt output voltage to inverter input voltage, while under load, as many have suggested. And a check on the actual draw of the MW needs to be done.

jrnymn7 wrote:
Have you ever tried running the MW immediately after turning off the charger, while V is dropping, but is still somewhere between charging V and actual V ?

No, but it's not a fair test of batteries, since that situation is not all that frequent.

2oldman,

Have you ever tried running the MW immediately after turning off the charger, while V is dropping, but is still somewhere between charging V and actual V ?

jrnymn7 wrote:
Would the solar help keep the voltage up while under such a heavy load? I'm guessing it's a pwm controller.

Thanks, and not that small panel.

4 amps of solar will not do anything against a 140 amp draw. What it can do is get the batts up in SOC somewhat after a day on solar so when you go to use the MW to make supper, you are in a better position.

In the other thread he said he had 85 watts of solar.

From the OP's other thread:

"Yes maybe I should have let the surface charge settle down, I do believe my new batts sit at about 12.90 after surface charge is done, it has a 85 watt solar panel that keeps it at this voltage."

Would the solar help keep the voltage up while under such a heavy load? I'm guessing it's a pwm controller.

I get almost a 1 volt initial drop to the "real" loaded voltage by turning the microwave on with inverter. Then voltage slides down slowly as the MW runs. If there is a surface charge (from being on solar) on the bank it disappears immediately in the initial drop.

That is why I can't run the MW at less than 50% SOC. I need 12.2v going in to stay above 11v alarm. That is on four 6s the way I am set-up. On two 6s I would need to be at 75% SOC to stay above 11v alarm (based on a test for that I did).

With 12s it is a little better, where you don't get as much initial drop. Guys here with AGMs report they can run their MWs with just two batts with not much initial voltage drop.

So if you can only carry two batts and you want to run the MW when at lower SOCs, AGMs are the way to go.

I do not understand the OP's situation or description of what is happening, but I do understand his frustration! :( RVing is fun if you don't weaken. :)

jrnymn7 wrote:
The bank had just come fresh off a charge, and still had a significant amount of surface charge. Perhaps that could account for the seemingly small dip in voltage?

Not in any experience I've had. Large amp draws always cause large voltage sags, especially with 2 batteries, even with solar input. And no, we don't know OP's solar complement either.

I noted that a solar controller was mentioned at the top of this page. I may have missed it, but I didn't realize there was solar input as well. Does the OP have a large array capable of providing quite a bit of amperage for use by the inverter, reducing the load on the batteries enough to match the observed voltage drop?