3kw battery bank.

[karrak]

A two kW inverter sounds fine for your usage. It will allow you to run the majority of products that plug into a 240V 10A wall socket. It will also run a fridge and small pumps.

There are several 2kW-2.4kW 12 volt inverters from reputable manufacturers on the market. Problems with running 12V is that you will need at least a 60A charge controller and you will not be able to upgrade to a larger inverter without changing to 24V. If you run 24V you will only need a 30A or 45A charge controller and all the cabling will be smaller and cheaper. I think it would be worth doing costings at 12 volts and 24 volts with a 24V to 12V converter to run all your 12V equipment. Might also be worth costing a 48V system with a 48V to 12V converter as well.

With the description of your loads I am surprised that you need 3kWh per day. In winter we run a fridge, lighting, computers and other electronics, electric toaster, microwave, induction cooktop and electric kettle on around 3kWh per day, the majority of cooking and heating is done on a wood stove. In summer we use around 5kWh per day with all cooking being done via electricity including a very efficient electric oven.

Simon

Off grid 24V system, 6x190W Solar Panels, 32x90ah Winston LiFeYPO4 batteries installed April 2013
BMS - Homemade Battery logger github.com/simat/BatteryMonitor/wiki
Latronics 4kW Inverter, homemade MPPT controller

[Floating down here]

[QUOTE=Mike90250;n366816]. i'd ditch the coffee maker and use the stove top.

whoa, I'll pretend you didn't say that and I'll hold my wife back so she can't get to you.

losing the coffee machine is a big negative, the outboard will go before the coffee machine.

[Mike90250]

OK, here's a slightly complicated alternative - 2 inverters. 1 small efficient one you leave ON all the time to run the cell phone charger, and LED lighting. The other is the big 2Kw one you switch on only for the big loads, and switch off afterwards (unless the coffeemaker has a clock timer in it) Doing this, saves you the idle power looses of running a big 2Kw inverter (maybe 50 -100w with no load) just to keep the 5 watt cell phone charger going

[Floating down here]

A two kW inverter sounds fine for your usage. It will allow you to run the majority of products that plug into a 240V 10A wall socket. It will also run a fridge and small pumps.

There are several 2kW-2.4kW 12 volt inverters from reputable manufacturers on the market. Problems with running 12V is that you will need at least a 60A charge controller and you will not be able to upgrade to a larger inverter without changing to 24V. If you run 24V you will only need a 30A or 45A charge controller and all the cabling will be smaller and cheaper. I think it would be worth doing costings at 12 volts and 24 volts with a 24V to 12V converter to run all your 12V equipment. Might also be worth costing a 48V system with a 48V to 12V converter as well.

With the description of your loads I am surprised that you need 3kWh per day. In winter we run a fridge, lighting, computers and other electronics, electric toaster, microwave, induction cooktop and electric kettle on around 3kWh per day, the majority of cooking and heating is done on a wood stove. In summer we use around 5kWh per day with all cooking being done via electricity including a very efficient electric oven.

Simon

Off grid 24V system, 6x190W Solar Panels, 32x90ah Winston LiFeYPO4 batteries installed April 2013
BMS - Homemade Battery logger github.com/simat/BatteryMonitor/wiki
Latronics 4kW Inverter, homemade MPPT controller

I wasn't aware of a 24/48v-12v converter available on the market, good stuff.

the 3kwh has been a very liberal calculation with the energy draws rounded up. If I wanted to scrimp and be more conservative I could probably get away with closer to 2kwh a day but there are certain members of our family that aren't the most energy conscious.

[Mike90250]

........ there are certain members of our family that aren't the most energy conscious.

Then they (and you) are due for a rude awakening.

[SunEagle]

[QUOTE=Floating down here;n366820]

. i'd ditch the coffee maker and use the stove top.

whoa, I'll pretend you didn't say that and I'll hold my wife back so she can't get to you.

losing the coffee machine is a big negative, the outboard will go before the coffee machine.

LOL. But your batteries may go quickly if you use that coffee maker. Take your pick: coffee from the stove or new batteries every year.

[TommyDre]

You already have a 2000 watt generator which is plenty of power to run that Mr. Coffee (drip?) for about 10 minutes per pot. And it can also handle that Proctor Silex toaster if you don't toast your bagel while brewing your coffee. Proper maintenance and it will last a couple of decades. That's provides all kinds of autonomy. Using the generator helps keep your battery cost$$$ down. There are some fairly decent 12 volt water pumps out there that you can use for the toilet, etc. Get $$ deposits from the people that can't control their flagrant use of electricity before they get on the boat. Now you can size a 12 volt system that doesn't break the bank, can fit on your boat, and doesn't need that big inverter.

[Floating down here]

Thanks for everyone's input. I've had a few issues with getting a system up but I think I've come up with something. Ive decided to go with a 24v system with a dc/dc stepdown for those pesky 12v water pumps. I'm a little curious about the pv array and perhaps someone can guide me.

4x190w pv panels
Imp-5.2A
Vmp-36.6
Voc-45.2
battery bank-24v@100ah (? 150ah looks better)

(no coffee machine, microwave, toaster on system)
total ah draw in 24hrs = 45ah.

questions:
would these panels be sufficient to provide charge to bank?
With 150ah bank does this sound right?

pv array watts-760

hrs of sunlight-6
watt hrs-3600
watts of pv array needed-600 (+20% for inefficiencies =720)



would i I wire the pv panels in parallel? If so would this be correct:

v=36
A=20.8
W=760



if all of this is feasible what would be the best CC for my application? Morningstar TriStar TS-MPPT-30 Charge Controller?



Cheers.

[PNW_Steve]

I don't know why you all think I'm after a 4Kw inverter, I never stated that. I did state that my requirements were 3kwh a day and my single highest drain in around 1.2kw in the form of a coffee machine so as I mentioned before, a 2kw inverter should be sufficient.

because this is all for a houseboat the few electronics are 12v (lights, toilet, pumps, windlass etc). Fridge, water heater and oven are LPG.

If you look at going 24v, there are ledights, bilge pumps, house water pumps, USB chargers and windlass all readily available. For boat electronics that require 12v there are 24v-12v converters.

If you are sharp enough to properly install a 12v system then a 24v system should be no problem. Read & ask questions. The folks here will guide you.

Good luck.

[PNW_Steve]

If you must use an electric coffee maker look for one with an insulated carafe or buy a separate one Once the coffee maker is done brewing you don't need a hot plate draining your batteries.
If you have some 12 volt lighting, water pumps and electronics aboard and you do have space available you can run a separate small 12 volt system. Works great for me.
If not done already replace all incandescent lighting with LED lighting. Stay away from anything in the "cool white" range.
Consider AGM batteries. Fullriver makes some quality deep cycle AGM batteries. Careful with telecom float service batteries, they aren't built for deep cycling.

Heat generating appliances like your coffee maker, toaster oven, laser printer etc are not very off grid friendly.

I have switched to a Cuisinart coffee maker that grinds the beans and then brews into a nice carafe. I really love it. Coffee stays good and hot and never burned. However, I think that I am going to pick up a French press for when we are dry camping. I will trade propane for electric for my morning coffee.

if I could only find a propane hair dryer for my wife

[littleharbor]

if I could only find a propane hair dryer for my wife

They have those high volume/low pressure blowers for inflating pool toys , air mattresses ,etc. They actually sort of look like a blow dryer. While they don't blow hot air, they do blow a LOT of air. Once we got a friend to join us on a camping trip, who's wife said he'd never go camping because he HAS to blow dry his hair. While it may take a bit longer, it does work.