Simple tool to figure out how much battery storage you need.

[yaakbus]

Over the last few days I have been asking people how much power they use in their bus. What I have come to figure out is, many people struggle with the conversions.

So here is an easy to use way to calculate how much power you need. https://everydaycalculation.com/ah-kilowatt-hour.php

My system needs about 6kwH per day. And I want to have enough storage to last 4-5 days without needing to charge anything. So for 5 days I need at least 30kwH total. But to ensure I am only using 50% of the battery, I need to double my storage amount to 60kwH.

A lot of people struggle to then figure out, how does that convert to aH (Amp Hours). In the example below, you will see that 60kwH or 60,000wH would require 1250aH of battery storage to run for 5 days, using 6kwH per day without needing to charge.

[o1marc]

Is the 5 day storage based on not being in the sun for that period? If everything is working properly is the system maintaining itself if charging correctly?

[yaakbus]

Exactly. I hunt and fish in Alaska and Norther Canada a lot and there are times in the winter when there literally is no sun. So rather then have to start the generator every few hours to keep things charged, I just wanted to make sure that I never had worry about power. And if I did, know that 5 gallons of gas could recharge my system 3-4 times before being in a whole world of ****. So what I am trying to do is by me a full 30 days in the middle of know where, incase something goes sideways and need to call for help via sat phone or there is a massive storm that I need to ride out.

Originally Posted by o1marc

Is the 5 day storage based on not being in the sun for that period? If everything is working properly is the system maintaining itself if charging correctly?

[yaakbus]

And that is if I consumed the power like I normally would. If I only used it for heat and lights, I could ride it out for much longer.

Originally Posted by o1marc

Is the 5 day storage based on not being in the sun for that period? If everything is working properly is the system maintaining itself if charging correctly?

[o1marc]

Have you considered a switch to charge the batteries off the engine alternator? Another safety feature if your stranded in the boonies.

[yaakbus]

I have but that also means using the diesel I need to drive out of the boonies, to stay warm. Running out of fuel would complicate the problem haha.

But I like where your head is, off-grid, like we the freaking heck off grid haha.

Originally Posted by o1marc

Have you considered a switch to charge the batteries off the engine alternator? Another safety feature if your stranded in the boonies.

[o1marc]

Originally Posted by yaakbus

I have but that also means using the diesel I need to drive out of the boonies, to stay warm. Running out of fuel would complicate the problem haha.

But I like where your head is, off-grid, like we the freaking heck off grid haha.

So your choice becomes stay warm or get the hell out. How long can you run to charge the batteries on a gallon of fuel?

[yaakbus]

It will take about 5.5 hours to fully charge the system from the generator. And my generator will run for 20+ish hours on 5 gallons of fuel.

I have not calcualted it from the bus but I imagine its not as fast as the generator.

Originally Posted by o1marc

So your choice becomes stay warm or get the hell out. How long can you run to charge the batteries on a gallon of fuel?

[Yukon Cornelius]

Love the thoroughness towards efficiency and longevity for your off grid boondocking, as well as the location you choose to do it

[yaakbus]

Thank You! Definitely not an expert but for sure open to all views on how to achieve the goal. I had a little awakening from a pretty in depth convo on another post I made, but in the end got the outcome i was looking for!

[Yukon Cornelius]

Originally Posted by yaakbus

Thank You! Definitely not an expert but for sure open to all views on how to achieve the goal. I had a little awakening from a pretty in depth convo on another post I made, but in the end got the outcome i was looking for!

So long as there was a takeway that was of benefit that's what matters

[cadillackid]

thats a lot of KwH of storage.. might be worth reading up on some of the threads about people re-purposing electric vehicle batteries, Lithium cells can be a bit daunting but when maintained the amount of power you get per lb in weight is a pretty good yield,



im thinking I would also carry double the fuel i would need to get in and out, just in case something goes wrong.. an exytra tank of gasoline.. even 15 or 20 gallons in a tank mounted under bus could save you a lot of grief if for some reason a freak storm came up, or an extreme cold snap where you need to run the generator more or so cold your battery yield drops..



as well as finding a way to carry more diesel fuel on case you should need to run the engine for supplemental heat or electricity..



are you planning on heating with fuel or purely electrically?


-Christopher

[yaakbus]

The heater, hot water heater and cooking stove all use propane with electric ignition. I have a main propane of 100lbs and two spare at 40lbs.

I am sure my power plan will be way way more than I need but at the same time but being in the middle of know where I just want to maximize the time I can be off grid.

Originally Posted by cadillackid

thats a lot of KwH of storage.. might be worth reading up on some of the threads about people re-purposing electric vehicle batteries, Lithium cells can be a bit daunting but when maintained the amount of power you get per lb in weight is a pretty good yield,



im thinking I would also carry double the fuel i would need to get in and out, just in case something goes wrong.. an exytra tank of gasoline.. even 15 or 20 gallons in a tank mounted under bus could save you a lot of grief if for some reason a freak storm came up, or an extreme cold snap where you need to run the generator more or so cold your battery yield drops..



as well as finding a way to carry more diesel fuel on case you should need to run the engine for supplemental heat or electricity..



are you planning on heating with fuel or purely electrically?


-Christopher

[Doktari]

Hello thread. Are you extinct or merely dormant. In the end one takes what fits, what’s affordable, and what one can get then make do with it. But asking what other people use is interesting and useful. Taking a vehicle into remote places has inherent risks obviously. Redundancy is often wise. I don’t remember reading anything in the thread about spare parts, spare generator, spare batteries, starting batteries, backup heater, and backup plans. But that’s another thread. I would have at least some solar panels. Even in Poor conditions there would be some generation for emergency use.
Reminds me of my photographer friend who goes to Yellowstone in the Winter. He built a double insulated box on his pickup to camp in like a badger in a den. There’s a small crowd of other photographers even when it’s bitterly cold. Doesn’t appeal to me lol.
A 200 amp hour battery is what I could get, what fit, and what I could afford at the time.

[Mudhutwarrior]

If you tend to be out in the wilderness a good option is a small wind genny on a fold over crank up mast. Would need some thought to do it but my plan is a square tube mast with the fold over at the roof break. Use a similar mast at home for Ham radio use.

If your truly a mad man you can look for air operated masts similar to what tv remote trucks use. They get seriously expensive and used ones are failure prone. But if your into showing off and overall cool that's a trick option.

My sailboat had an Air-x marine version on a 12'foot mast. With 8 golf cart batteries I never was short of house power.
Biggest issue is no wind genny is quiet and the Air-x would electrically short to stop spinning when it reached full charge. Even after a lot of tweaking of the stop voltage you would regularly hear a thud as it stopped.
Also the Yacht club put me out at the farthest mooring because people complained of the whoosh whoosh sound as she spun.
With considering that its still a great back up to solar and still much quieter than a generator unless you running a compact and then your charging would be considerably long in run time.

[Brewerbob]

Originally Posted by Mudhutwarrior

Also the Yacht club put me out at the farthest mooring because people complained of the whoosh whoosh sound as she spun.
With considering that its still a great back up to solar and still much quieter than a generator unless you running a compact and then your charging would be considerably long in run time.

What kind of wind speed are you looking at?

Depending on where he's at in AK, wind is NOT a good option. From what I understand from a tour bus driver, Fairbanks is dead calm. -70°F but dead calm. He hated Anchorage because it was -20°F but windy and rainy/snowy/damp. The two cities seemed to be old rivals. Fairbanks sucks because it's -348954725°F. Anchorage sucks because it was raining and 892359721mph winds. You could certainly tell where people were from!!

[Mudhutwarrior]

I tend to stay near the coast or higher elevations. 10 kts and your charging with an airx. I agree it won't work everywhere but its just another bolt in the quiver.

[Brewerbob]

Originally Posted by Mudhutwarrior

I tend to stay near the coast or higher elevations. 10 kts and your charging with an airx. I agree it won't work everywhere but its just another bolt in the quiver.

Good to know. I'm not knocking at all just have zero experience with wind or solar. If they aren't too big and/or heavy, I'd be all for running something up a flagpole setup.

[Brewerbob]

P.S. I follow Dzlfreek on Youtub; lives out in the Nevada boonies somewhere. He has a "fancy" (read as a stouter than usual) flag pole in his yard with a wind generator on it. He isn't off-grid by any means but he's saving a few bucks each month on electric with his setup. I don't know if he plans on making it mobile with his bus or not.

[Mudhutwarrior]

Originally Posted by Brewerbob

Good to know. I'm not knocking at all just have zero experience with wind or solar. If they aren't too big and/or heavy, I'd be all for running something up a flagpole setup.

I have had very good luck with the air-x on the boat. Three years without issue and always on the water. On land my only concern is the power cable which well pump wire is generally used is not connected by a rotary coupling. Instead its direct connected and allowed to twist. In fickle winds the twisting of the cable might be an issue but with it masted only 10' on the boat I never had issues. I would think that's a minimum in mast length to avoid wrapping the cable to to tight in variable winds. So if you figure on a fold over one has to consider the cable running through the center of the mast. The blades are easily removable from the hub so you could drop it right on the roof during transport. Would need some type of cradle for it and the ability to walk it up. Trying to do it as a crank up would cause too many issues with hanging off the back and the wire running through the center. An air lift mast would be the trick item for such and install and they can be had pretty cheap used. I found one for scrap price but the issue was the manufacturer no longer supported parts for it.