Inverter Question

Started by diyfrank, October 09, 2011, 10:38:39 PM

Previous topic - Next topic

0 Members and 1 Guest are viewing this topic.

diyfrank

http://www.theinverterstore.com/the-inverter-store-product.php?model=pwric150012s#

I'm thinking of something like this set up for the cabin. Right now I use a small inverter for the coffee maker and microwave and a 5000w generator for more serious power needs.

Am I thinking right that I could use this with the generator and charge the battery's during the day while its in use then have it automatically switch to battery use in the evening and morning hours when the generator isn't in use.

I think it could handle the power needs as long as the generator can safely charge the battery's through the inverter.
Home is where you make it

MountainDon

How many and what capacity are your batteries? The charger section is rated at 10 amps output. That's not really very much, IMO.

Yes, it would automatically switch between battery and generator when the generator is started/stopped. I didn't see if it has a delay to give the generator a chance to warm up before being placed under load.
Just because something has been done and has not failed, doesn't mean it is good design.


diyfrank

I was assuming when the generator is hand started it would charge the battery's and when shut down would draw power from the battery's. The generator would be the primary source of power.

I have 2 6v 225 amp/hrs battery's. The sales man said 10 amp max is recommended for recharging. What rate do you recharge at?
Home is where you make it

Squirl

BS on the charge rate. Charge controllers and all xantrax models go way higher.  (40 to 80 amps) I'm not a big fan of sales people.  With the charge rate you would have to run that 5000 watt generator for an hour to get 120 watt hours dc.

diyfrank

I'm not sure what 120 watts an hour will produce but I've been running the generator daylight till dark pretty much on around 4 gallons of fuel then I run lights and a bug zapper light for a couple hours off the battery's. In the morning the coffee pot is preset to 6:30 and some breakfast is microwaved, 10-20 minute of use. Then the generator is fired back up. If walking around the woods or napping I shut it down. I have been using a battery charger plugged into the generator to do the same but would like a little better inverter for off generator hours. I may just buy a couple more batterys and go with 24v but unsure what to do for recharge. My charger is 12v.  :-\
Home is where you make it


Squirl

I hope you didn't take the BS comment directed at you but at the sales person.  I am probably going with a Xantrex TR series.  They can charge at 70 amps.  They are a little more expensive ($100?) than the AIM  model and aren't pure sine wave.  They are a step wave.  From what I have read, there are varying degrees of stepped sine, from the square wave to the pure sine.  The higher end MSWs step the wave multiple times so it looks identical to a pure sine to most devices.  I have had a lot of experience with them in sailing and never found anything that didn't run on them.  I also researched this in RV forums and I came to the same conclusion.  They are also UL listed, which gives an extra piece of mind to the safety factor.

It all depends on how much you are willing to spend and what you want.  I have seen people get a cheap 40 amp 12v automotive charger and a manual switch to switch between the generator and inverter.

CjAl

what kind of generator are you running just out of curiosity? My gas.genny burns alot.more gas then that. Im trying to find a listeroid diesel setup. Low rpm, quiet, fuel efficient and it will run.on diesel, used motor oil, cooking.oil or pretty.much anything else you pour in the tank

i have used modified sine wave invertors for years in the semi truck. I have a refridgerator, microwave, flat screen lcd, dvd player, nintendo, vacuume, laptop and printer. It all works. The only thing i have found is that microwaves run a little loud but i buy the chrapest ones i can and have never burned out out. I had a small 800 watt all mecanical one that i used a few years then put it in the house. Now i.have a 1000 watt magic chef and it is still working. Refridgerators i go through about.one dorm fridge a year but i think its more because.of the bouncing and vibration then the invertor. Laptop transformer.runs a bit hot but its not a problem. I was told the tv would have static or line in it but it doesnt. This is on a cheap 2500w cobra invertor.nothing anywhere as nice as what youd put in a house

Squirl

For perspective you have 2-6v 225 amp hour batteries wired to 12 volts.  So you have a capacity of 12x225 = 2700 watt hours of capacity.  If your batteries were fully drained it would take 22.5 hours for your generator with the aim inverter to charge your batteries to full.

How are you charging your batteries now?

MountainDon

#8
For battery charging a good rule of thumb is C/10, where C is the amp hour rating (225).  225/10 = 22.5 amps (at 12 VDC).  

When/if the batteries are fairly low that can be boosted to C/5; fairly low being a state of charge of 75% or less as measured with a hydrometer.

When the batteries are near full (95% SOC) reducing the charge rate to C/20 is good.

The best chargers, whether a stand alone or an inverter charger, will have a battery temperature sensor available. That reduces the rate of charge if the batteries get too warm. Also if you were to charge your two batteries at a rate of 60 - 70 amps they would need water added more frequently and if they reached too high a temperature during charge their life will be shortened.

The size of the charger should be matched to the capacity of the battery bank.

I am an advocate of 24 VDC alternative energy systems. While it is true that there are not as many choices for some equipment in 24 VDC you can still find pretty much anything you want or need. For a good stand alone three stage battery charger look up Iota; models in 12, 24 and 48 VDC. They do not have equalization capability, but then neither do most of the inexpensive chargers or inverter/chargers.

In our RV we used four 6 volt cart batteries in series parallel for a 12 VDC system that had a capacity of 500 amp hours. 500 /10 = 50. I used an Iota 55 amp charger. With the 3 stages it tapers down to a float as the batteries reach full. My generator is an inverter charger and I could tell by the sound of it when the charger would shift stages.
Just because something has been done and has not failed, doesn't mean it is good design.


Native_NM



I have this:

http://www.tripplite.com/en/products/model.cfm?txtModelID=2939

and it works great.  Gen set runs at night, when we have to have construction lights, and the batteries charge.  During the day, we run off the inverter.  Computers, printers, chargers, etc.
New Mexico.  Better than regular Mexico.

diyfrank

 Squirl , Thank  you for your thoughts they give me something to think about and no, I didn't think your BS comment was directed at me. I'm currently using a 12 amp charger from batterycharger.com

CjAl , I was using a 3500 watt champion and now use a husky 5000 watt. Both are cheap generators but you can't beat the bang for the buck. the Husky is using 4 gallons in 13 hours of run time mostly running power tools /compressor and the battery charger.

MountainDon , As always a lot of good information there. I found an old 1960s? charger in my shop. It's a Marquette Redi-fast model 322ns  It charges at 80-100 amps at 6v and 40-50 at 12v. I'll drag it up to the cabin and hit them with a few amps.
I'll be looking into a better step charger before long.
I'm still thinking I need to up grading some on my inverter.  My $29.00 harbor freight 1500w has worked but it may be time to creep into something better.
Home is where you make it

diyfrank

Quote from: Native_NM on October 10, 2011, 03:58:42 PM

I have this:

http://www.tripplite.com/en/products/model.cfm?txtModelID=2939

and it works great.  Gen set runs at night, when we have to have construction lights, and the batteries charge.  During the day, we run off the inverter.  Computers, printers, chargers, etc.

Looks like a good unit. Amazon has it for just under 4 bills and free shipping.   What is PWM sine wave and how does it compare to pure sine wave?
Home is where you make it

Native_NM

Quote from: diyfrank on October 10, 2011, 11:26:11 PM
Looks like a good unit. Amazon has it for just under 4 bills and free shipping.   What is PWM sine wave and how does it compare to pure sine wave?

Here is a primer on the types of inverters and their output.  Pure sine inverters are very expensive, comparatively speaking.  Some equipment will not run on modified sine wave inverters.  One trick is to buy two inverters - a high wattage modified wave, and a lower wattage pure sine wave.  Battery chargers often will not work on modified wave inverters.  One exception (at least for us), is the laptops charge right up without a problem. 

http://en.wikipedia.org/wiki/Inverter_%28electrical%29

New Mexico.  Better than regular Mexico.

Squirl

Good deal on your current one.  If everything you are running runs off of the cheapest modified sine wave, is there something prompting you to spend the extra money for pure sine wave?


MountainDon

Much of the time the little "wall wart" type of charger have issues with square waves. That's the little cubes that plug directly into the receptacle. The type of charger/adapter that has a proper AC cord that plugs into the wall usually work on square wave. As someone noted they do sometimes run warmer. The little cubes can run so warm they lose their magic smoke and never work again.

Motors run hotter and use more power on square wave. Some microwaves do not work. Some computerized sewing machines don't work on square wave. Sometimes lights buzz on square wave.
Just because something has been done and has not failed, doesn't mean it is good design.

Squirl

I have found a cheap and easy way to test for that.  I bought one of those cheap $10, 100 watt inverters for cars.  Cheapest square wave you can get.  All my phone chargers including the Iphone, laptop, and Makita battery charger worked on it.  You can return the chargers before leaving the stores parking lot.  d*

CjAl

My toshiba laptop charger ran a little warm. The plug broke off and i.bought a $2 chineese replacement on amazon. It works but it gets hot enough to burn you if you roll over on it.

Just a FYI, many of those smaller cheaper generators are invertors not actual genny's. Those 1000 watt hondas you can plug into each other to run in series are invertors

also many generators can have a dirtier wave then the better modified wave invertors

diyfrank

I made a choice http://www.ebay.com/itm/130448925823?ssPageName=STRK:MEWAX:IT&_trksid=p3984.m1423.l2649

Best price on this type of inverter/charger I could find was Ebay. This will give me more watts, selectable charge rate, equalization program and battery temp sensor. It has a jack for starting and shut down of the generator if I move into that direction. It's a couple hundred more then I was looking to spend but sometimes you have to bite the bullet. d*


I'm basically cheap by nature and this gets me at $1215. for 5000w generator, 2 6v 225 amp/hour battery's and inverter/ charger with a output of 2000 watts continuous when gen is off and 5000w continuous with it on. [cool]
Home is where you make it

Squirl

25 to 100 amp selectable charging too.  You could charge your batteries in 2 hours with that.