Whats a Good Brand for a Inverter

Am I just lucky or something? I've never had an inverter fail. I have:

1. An old (bought used) Xantrex 2000 PSW (not 2.0 - it's the predecessor) that runs my sump pump during power outages from an 880 AH bank of batteries, connected using 4/0 cable and 4/0 interconnects. It's been in place for 7 years, has cause to operate several times a year, and has never let me down.

2. PowerBright 300W PSW inverter that I've been using while camping for about 12 years now. It has been used on almost every trip but probably will get much less use now due to #3.

3. New MicroSolar 1000W PSW inverter for use while camping (very inexpensive - this one could be interesting to watch how long it lasts).

KJINTF wrote:
Inverters R US

How long have the COTEK guys been around?
Are they somehow connected to the Zantrex/Heart/Trace engineers?

They do indeed look like a good value - just wondering how long they have been in the field and operational

COTEK has been around quite a while, I know the SK series that the SP Series replaced has been used for over 7 years. They made inverters for other companies like Samlex as well. I received your pm KJINTF, getting to it now, sorry I was offline most of yesterday/last night spending time with the wife.

I will do more test and check system where the low shut off is, might even set it to default, not sure where its at, maybe I can get this working right again, who knows..

Got to go for now..

Voltage Drop Calculator

... scroll down for calculator

Cheapo terminal rings could also be adding to voltage drop, as well as any circuit breakers in the circuit. This is why you must compare Vbatt with Vinput at inverter, while under load, to determine how much voltage drop there is. Keep in mind, as current (amps) goes up, so does voltage drop; whether charging or discharging.

Do a series of tests over the next week, checking different things as you go, and try to cross verify all readings. Don't rush it.

This is why it's important to know what is "normal" for your system... eliminates a lot of guess work, and perhaps some unwarranted purchases. And let's face it, those charger/inverter combos are big bucks... one reason I personally would never go with a combo unit.

There may also be a very sudden voltage drop... too fast to notice, that may be actually dropping Vbatt lower than it appears, but for only a short moment. This could be causing the inverter to shut down. And undersized wiring/line loss would only exacerbate the issue.

jrnymn7 wrote:
If your Vbatt did actually drop .13v, from just 20 seconds of microwave use, then that's a loss of about 22 Ah's on a 200Ah bank. That seems highly unlikely, seeing as 1600w/120v = 13.33a x 10 = 133Ah's per hour x .00555 hours = 0.74Ah's.

... So it was definitely surface charge being burned off.

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.

I even think now it might have read 13 volts on tester at time of micro wave testing, I was not really looking at that was just checking how low the batts go during micro use and checking to see if any voltage loss between batts and inverter.

If your Vbatt did actually drop .13v, from just 20 seconds of microwave use, then that's a loss of about 22 Ah's on a 200Ah bank. That seems highly unlikely, seeing as 1600w/120v = 13.33a x 10 = 133Ah's per hour x .00555 hours = 0.74Ah's.

... So it was definitely surface charge being burned off.

EDIT:

The point being, even though Vbatt was at 13.3v, the bank may not have been fully charged. It can take several days for a significant surface charge to be self discharged.

jrnymn7 wrote:
Do your batts usually have a resting ocv of 13.3v, or is that surface charge from just turning off the charger?

"Test 1 : After shutting the main electric off and running on batts only the batts read 13.3 volts on meter, "

On what meter? A handheld multimeter, or the inverters display?

"even at the solar controller panel, measured at back of inverter the same reading 13.3 volts,"

It is normal to see Vbatt at inverter output, and throughout the entire circuit, when there's no draw.

"so after test the batts voltage went back to 12.90 volts,"

How long after? It can take a minute or so to rebound. Loosing .13v in just 20 seconds sounds like it may have been burning off some surface charge. And have you compared various meters/displays for accuracy?

"We did another test with micro wave and voltage again dropped to 12.60 but than inverter kicked off only after 4 seconds and cooling fan on inverter kicked on"

What was Vbatt after 2nd microwave run?

Hand held meter and yes check right after shutting down main power, also not sure what the batts read after second test but it did not go below 12.60 because inverter kicked off but I believe I did see the solar panel and it said 12.90 before turning main power back on.

Volts came back fast on hand held meter.

I am going to check the low volt shut off where its at.

From the Prosine 2.0 Manual;

Page 77 of 148

Inverter Low Voltage Shutdown:

At or below this battery voltage, the inverter will shut down. The values range from 10–16Vdc.

Inverter Low V Warning:

This is an offset voltage ranging from 0 to 3.0V. When the battery voltage drops
below the sum of Low V Shutdown and Low V Warning, the PROsine will sound a warning.

Inverter Low V Restart Hysteresis:

This is an offset voltage ranging from 0.5 to 2.5V. When the unit has shut down
due to low battery voltage it will not automatically restart until the battery voltage recovers to the sum of Inverter Low V Shutdown and Inverter Low V Restart Hysteresis. When the PROsine shuts down the battery voltage will rise and may cause the PROsine to restart, which drops the voltage again so the PROsine shuts down, etc. This hysteresis setting reduces this problem. The default value is 2.5V and should not be changed unless there is a special reason for doing so or this problem will return.

... have you checked these settings?

What is the Low Battery cut off voltage set to?