Generator or batteries for boondocking?

[belfert]

As some here know, I mostly use my bus for one 4,000 mile trip every September.  We usually use the inverter at night when A/C is not needed.  My issue is my battery bank is shot.  I currently have six 100 amp hour AGM batteries.  I can't even run everything for more than a few hours on battery. 

Is it worth replacing the battery bank for something like $2,500 to $3,000, or just run the generator all the time?  I figure an extra 50 to 75 gallons of diesel per trip for that.  Lithium batteries are probably out of the picture due to cost.  Lithium batteries can also be destroyed by excess heat, or by charging at 32 degrees F or lower.  It gets way below 32F in the winter although lithium batteries can be disconnected for the winter without issue unlike most AGM batteries.

[windtrader]

Many discount lithium which is surprising amongst us pretty capable DIY crowd. For some reason, most are comfortable with mechanical and construction projects but seem less inclined to DIY a battery system.


You can do a very robust lithium battery and/or solar system for pennies on the dollar if you are willing to put the time in to researching good sources and known how to qualify raw and already assembled battery packs.


Yes, there are operating considerations such as minimum charge temperatures. This is easily overcome by simply insulating the battery box and stuffing a low watt incandescent light to keep the pack withing operating range. You could also use a run of the mill small heating pad to the sea effect.


Excessive heat? Well, again insulated battery and well ventilated box stored in the bay will suffice in most cases. At worst case, put a small wall AC to keep within operating range,


Remember, you are not building some puny battery but one that easily exceeds 10kW to 15kW, lots of power to run all your stuff as you need.


Costs - Sure you can pay $1000 per kW for a plug-in battery like Battleborn or others. Why not DIY the same capacity for $120 per kW. When I built mine a couple of years ago, typical pricing is $100/kW; it's gone up some but not a crazy increase.


Being totally off the grid and off a genny totally is an incredibly powerful and freeing feeling. Makes it just like living at home within reason. Keep all the lights on as you want, run the microwave anytime, etc.

[belfert]

I already have enough things to do without spending dozens of hours learning how to build my own lithium battery bank having to deal with balancing cells and all that.  Heating batteries with a light bulb works great until the bulb burns out and you lose the entire bank.  (Yes, I could put in a temperature monitor.)  It would be a no brainer to use lithium batteries if I used my bus more than eight days per year. 

Aren't the really cheap lithium options done with used batteries from electric vehicles which may, or may not, be any good?

[windtrader]

If you use your bus only 8 days a year, maybe just sell it and rent an RV. WAY cheaper. My comment is simply that there seems to be a DIYer mindset and an observation that DIY on the electrical supply end generates less enthusiasm.


FYI - There are all sorts of batteries available on the secondary market, That is why I stated one needs to get educated before jumping in. In your case, it does not many any sense to pursue that and I apologize if you felt I was pressuring you that way.

[Utahclaimjumper]

Why not go old school and install 4 lead acids for about 500 bucks,, should last about 6 years with care..>>>Dan

[buswarrior]

Just run the generator.

Lithium is not cost effective for the weekend camper, yet...

And any significant battery bank makes no sence for once a year use, when there is a robust generator present.

Nobody that lives in the winter uses light bulbs for anything but light. Just about useless in Brian's locale. How many BTU in a lightbulb?

Building your own lithium batteries is in the same timing as building your own computer... we're just waiting for the flood of formalized assemblers to break the high priced stranglehold, and then no one except the extremists and hobiests will build their own.

Timing is everything...

Happy coaching!
Buswarrior

[windtrader]

If one is building a bus conversion today and has no generator then it would be prudent to look at lithium storage. I assure you if you are reasonably clever and willing then you can do batteries for less than a typical diesel generator. There are always naysayers, especially while in an early adopter stage. Meaning  - no point in expending energy trying to convince the inconvincible.

[richard5933]

It's a personal preference thing. If you're like me and hate disturbing the quiet of the woods running the generator all night then get some new batteries. If you camp where others won't mind the generator and you don't mind it, then run it all night long.

Me? I'd get some lower cost batteries to hold me through for a while.

[dtcerrato]

We have hybrid WLA on house bank & starters with remote battery latching relays so we have compatibility with both banks together either/or for the inverter/charger and retain our first generation conventional 40A charger for backup redundancy. Otr we run rooftop A/C with start batteries feeding inverter and 200A alternator keeping batteries charged. With a little solar sprinkled on all the works. Hardly need the genny but it's there...

[sledhead]

I just spent the summer camping on our lot waiting for power and using gennerator to charge my wet batteries when needed . It took about 3-4 hrs a day to bring them back up to 100% for the next night and so on .

The biggest problem with running the generators
(  a big 12k diesel , a 2500 gas inverter genny )
we had a problem with the diesel as if it was cool or the weather was in a low the diesel that went out the stack above the coach  exhaust would then flow down ? and hug the ground ?

so sitting outside or opening the windows was a no go

so we used the small gas genny with a 75'   6 gage cord far away in the bush so you could not here it or smell it but had to turn down the charging on the magnun to 60 % so other stuff would work when needed

It was fun but if there was a choise to not run the genny I would have gone for that . We do have 400 watts of solar but because we choise to be under the shade of the trees it did not help to much

I   2nd the buy new 6 volt batteries to save some use of the genny

ps     we now have 200 amps of power for the next camp out on site 

dave

[belfert]

My battery compartment is set up to use only AGM or Lithium batteries.  The compartment is not vented or sealed well enough for regular lead acid batteries.

The event I go to is out in the middle of the desert with many other generators running.  It isn't a quiet forest where my generator running will ruin the peace and quiet.

[rancher]

If I were only going on one four thousand mile trip a year I sure wouldn't invest a bunch of money in batteries when you have a generator. Years ago when we went sand railing in the boon docks we always ran our generator. Even if you have to buy 100 gallons of diesel its only once a year for you. If your boon docking all the time I under stand batteries.

[belfert]

If you use your bus only 8 days a year, maybe just sell it and rent an RV. WAY cheaper. My comment is simply that there seems to be a DIYer mindset and an observation that DIY on the electrical supply end generates less enthusiasm.

I looked into all options, including rental, before choosing to build a bus.  A motorhome, rental or owned, does not have enough beds for the five to eight guys that go on my trip every year.  Motorhomes also don't usually have as much water capacity as my bus.  Class A rentals are almost always gas and would probably struggle to pull a 7,000 pound trailer.  A rental gets pretty expensive when you are driving 4,000 miles in eight days and also using the generator from 12 to 24 hours per day.

My bus is very customized for what I do.  I have things like an outlet in the rear to provide 110 volt power to the trailer while in tow to keep a deep freeze running and an outside outlet that can provide up to 30 amps for powering all the stuff we use while at the event.

I'm not ruling out DIY lithium batteries, but it seems quite easy to make a mistake and cause a fire, or worse.  I do all my own electrical in my bus and my house and don't worry about electricity for those projects.  I even get permits for work on the house and have always passed inspection first time around.

[chessie4905]

I would go with 2 smaller gas generators with parallel kit and use the batteries you have. For once a year big trip, would be the better idea. No need to have expensive batteries to take care of 11 months out of the year. Lot of expensive new age battery leg humpers here lately. Yes, those batteries are good but not desirable in your situation. Maybe adding some solar for assist though.

[belfert]

I already have a 12.5KW diesel generator.  I am just trying to decide if getting a new battery bank to cut down running time on the generator by about 1/3 is worth it.