Any inverter that can run without grid/battery?

Re: Any inverter that can run without grid/battery?

WolfgangStiler . Why do you think all systems use expensive batteries if there was something else that was cheaper and required less often replacement ??
There is just no other cheap and effective way as yet around the problem.

Re: Any inverter that can run without grid/battery?

At this point the PV system may be enough to provide some needed heating or cooling.

Probably not, just take to much solar to heat and cool. Look into a generator for emergency backup.

Re: Any inverter that can run without grid/battery?

You could get a Xantrex XW inverter. If I remember the smallest battery bank to even out the solar input is about 100amp minimum. So you could get by with about $400 in batteries and most of the time use it as grid tie. You would also need a solar charge controller so another $600. That is about the only way to make it work.

Re: Any inverter that can run without grid/battery?

remember that you can only drain the batteries down to about halfway as deeper discharging will be detrimental to the battery life. use it if you have to (aka emergency), but just don't expect a minimal battery setup to power things for too long. example 100ah 48v bank can use 50ah at 48v for a total of 2400wh and may not accommodate high wattage loads without bogging down the batteries. there aren't easy cheap answers unfortunately.

Re: Any inverter that can run without grid/battery?

RWB wrote: »

Or you can use LFP Batteries...

Not without battery management electronics and smart charger. For the price of 160Ah 12V LFP set of batteries only ($ 704) the OP can get almost 900Ah at 12V of golf cart lead acid batteries and no need for custom battery management electronics.

Re: Any inverter that can run without grid/battery?

AntronX wrote: »

Not without battery management electronics and smart charger. For the price of 160Ah 12V LFP set of batteries only ($ 704) the OP can get almost 900Ah at 12V of golf cart lead acid batteries and no need for custom battery management electronics.

Yea all you need are a Balancing Module for each cell so that it will keep you from over charging each cell and keep the cells balanced, and the same balancing Module has a output so you can hook up a Relay for a Low Voltage Disconnect if any of the cells drops below 2.5V. It simple and cheap, 4 balancing modules will cost you $100, if you want the Low Voltage Disconnect feature then just pick up a relay to cut your batteries output off and it will automatically turn the output back on once all the cells are within the perfect cell voltage range of 2.8-3.6V.

Just depends on if the OP wants 900 or more pounds of batteries which will take up much more room which may or may not matter. To get the same life span of 3000 cycles you would only want to drain the batteries to 30% or so vs 80% with LFP. So 900AMP Hours x 30% for a 3000 Cycle Life Span = 270Amp Hours of Usable Amp Hours vs 200 with LFP.

If you want to just let those 900Ah of Lead Acid Batteries just sit there and only use them for emergency situations and then drain them to 80% during a emergency situation then that would work good. But my partner has thrown away 15 Lead Acid Batteries that were quality and he kept them charged every month or 2 to maintain them, they were AGM and they all went bad over a 1-1.5 year time span. So from our experience these AGM batteries do not last very long when you let them sit there and not get used. Maybe if they were all hooked up to a Solar Charge Controller and float charged every day they would have been fine but it basically proves to me that these batteries need to used often or else they risk dying a early death.

The Thundersky LFP Cells have a 1 year warranty, if a cell dies they will replace it.

LFP Batter Tech is basically superior in all ways it just cost more up front to buy them, but they are actually cheaper than lead acid batteries over the long haul because you do not have to replace them near as much as you do with Lead Acid type batteries. They are almost 2 completely different animals really.

If your going to be using the Batteries Daily then a 1000Ah Bank of LFP Cells will give you 800 Amp Hours of Storage Everyday for 8.2 Years, and then you battery bank will drop down to 80% of its initial 1000Ah Capacity, it will not just die on you just slowly drop its total capacity over time. This is draining your battery bank to 80% every day. You can get 13.6 years if you only drain 700Amp Hours per day vs 800 amp hours.

Now to get a Lead Acid Battery Bank to last 3000 Cycles or 8 years you can only drain it to 20-30% on average everyday. So we would need 2500 Amp Hours of Lead Acid Batteries if you want that bank to last you 8 years with you draining the same 800 Amp Hours every day by discharging 30% of the banks capacity everyday.

The difference is 1500 Amp Hours between Lead Acid and LFP Batteries. The Weight difference is Crazy too. 1000 Amp Hours of LFP Weigh 64 Pounds per 200Ah 12V Pack so 64x5 packs = 320 Pounds vs 160 Pounds for a AGM 200 AH Battery x 13 to get 2500 Total Amp Hours = 2080 Pounds !

So that's a 1760 Pound Weight Difference.

5 200Ah LFP Batteries vs 13 200Ah Lead Acid Batteries to get the same capacity and life span. That's more than 2 times the amount of Lead Acid Batteries vs LFP Batteries to get the same results. The cost of LFP does not look so much more expensive once you start really looking at all the benefits and do the math.

Also you do not need a Smart Charger, Charging to 14.4V will work just fine. No need to Equalize either. Most Solar Chargers can be programmed easily with your desired bulk and float charges.