Inverter shopping

[beeman]

Hello everyone ... I've come to where the experts hang out to ask for some advise. I have a small off grid solar system at a cabin and am looking to upgrade my inverter. We use this cabin on weekends only and most of the time we're only needing enough juice for lights, radio, etc. ... we do have an exhaust fan for an indoor grill and a few other small appliances that would periodically require more power for short periods of time. We currently have 2 x 100 watt solar panels and two Trojan T-105 RE batteries. We're using a small 400 w modified sine wave inverter that I had kicking around and have to fire up the generator when we need more power. I'd like to get a 2000 watt pure sine wave inverter but am overwhelmed by the choices. We have a generator electrical panel with the two position main breaker to switch back and forth from solar to generator. Do I need a particular type of inverter to be compatible with a panel ? ... is grounding a consideration ? ..... we're on a budget so not looking to break the bank but would like to know we're getting the right inverter for the application .. thanks

[Mike90250]

Well, if you can manage your consumption really well the suresine 300w/600w 10 min inverter might do the trick. The vent fan might be troubling - maybe use the 400w inverter just when you need the fan.
But using a 2Kw inverter for daily loads of 300w and occasional blender or fan use, is wasting a lot of power idling in the Big inverter.

[Sunking]

Do not buy a large Inverter as it will eat your batteries and significantly increases the risk of Fire. A pair of Trojans at 12 volts will not operate a 2000 watt inverter and is begging for a fire. At 12 volts in my book no larger than 500 watts. Under no circumstances larger then 1000 watts at 12 volts and you do not have enough battery or panels to support a 1000 watt Inverter. Ideally your Inverter should be no larger than your panel wattage. A 1000 watt Inverter needs at least a 650 AH battery, you only have 225 AH

Let's make this simple so I do not have to explain everything. You have a pair of 225 AH GC batteries and they can handle a C/6 discharge current of 40 amps. The absolute largest Inverter they can handle is 500 watts. So 500 watts or LESS. Smaller is better.

Use 6 AWG wire and 10 amps of fuse for every 100 watts of Inverter. So at 500 watts a pair of 50 Amp Fuses, one on each polarity connected directly to the battery term post. Buy cables with terminals on them.

[jflorey2]

Another vote for the Suresine 300. It's a bulletproof inverter.

[Mike90250]

Another vote for the Suresine 300. It's a bulletproof inverter.

Naw, it's just an aluminum case, won't even stop a .22 !

6 years on mine, 24/7 and going strong.

[beeman]

Thanks for the info guys .. I'll look into the Suresine 300 ... apologize if this is a dumb question Sunking but what is the significance of panel wattage to inverter wattage if the inverter is drawing from stored energy in the batteries ? ... being a weekend cabin we get uninterrupted charging for 5 days a week with two days of use ... we're certainly new to all this and were thinking when we have more money to invest we'll buy more batteries not more panels ... and I understand the 225 amp hour battery spec but what is a GC battery ?

[Sunking]

Sunking but what is the significance of panel wattage to inverter wattage if the inverter is drawing from stored energy in the batteries ?

Harmony and balance. It allows you to use Solar power during the day, rather than batteries saving them for night. Your 12 volt 225 AH battery only has 140 AH (70 AH usable) if discharged at 2000 or 200 Amps. That is just a few minutes if the battery does not overheat.

have more money to invest we'll buy more batteries not more panels

Well you do not have enough panel wattage now to support the batteries you have. I assume you are using a PWM Controller. That turns your 200 watt panel into 120 watts or roughly 11 amps charge current. Your batteries require 20 to 30 amps to charge.

but what is a GC battery ?

Golf Cart. T-105 batteries are Golf Cart batteries.

[beeman]

Here's the panel / charge controller I bought .... https://www.amazon.ca/200W-Mono-Sola...s=solar+panels

The T-105 batteries are the RE version which I was told are optimized for solar applications having heavier plates, etc.