Lithium Package At Lower Cost

[Bob Denman]

What you need; is for some pretty smart engineers to start applying some serious brain-power to this issue...

[bry899]

Originally Posted by Chance

Are your panels rated at 1,300 Watts (325 each) or are you actually “producing” 1,300 Watts?

Assuming it’s standard “rated” capacity, you could get about 4,000 Watt-hours daily on sunny days — significantly more if parked in desert in summer. Anyway, your 400 Ah battery bank represent around 5,000 Watt-hours, so on sunny days you can discharge them pretty low and still charge them back up.

Now, let’s look at vans and small motorhomes with no generator which have greater battery capacity and must rely on them for air conditioning. The Cross Trek has 800 Ah of battery, which is about 10,000 Watt-hour (10 kWh).

It comes with up to 380 Watt solar as option, which should make about 1,200 Watt-hours daily. If you ran air conditioner all day or night so as to drain battery bank pretty low, it would take a week of solar at 1,200 Watt-hours daily to make 8,400 Watt-hours; assuming average sunny days for entire week, and that you don’t park in shade.

Just saying that when design goal is to go without a conventional generator, we need a lot faster way to charge batteries. And the faster that system can charge the massive battery bank, the less critical solar contribution becomes.

Thanks for the clear explanation and comparison.
Correct me if my math is wrong, but a generator has its limits also.
Ford Class C has a 55 gal fuel tank (Class B's might be smaller), IF the tank is full, then there is 42 gallons of usable gas for the generator.
An Onan 4000 uses a half gallon per hour at half load.
So the generator should be capable of 84 hours (3.5 days) of run time, before you have to refuel.
So what size battery would be equivalent to replacing the generator?
50 kwh? I guess it could be smaller with more solar production (weather permitting)

[Bob Denman]

What if you bought a bunch of "solar suitcases; and set them up in the Sun?
Six of them should get you up over 800 watts of theoretical power...

[Chance]

Originally Posted by bry899

Thanks for the clear explanation and comparison.
Correct me if my math is wrong, but a generator has its limits also.
Ford Class C has a 55 gal fuel tank (Class B's might be smaller), IF the tank is full, then there is 42 gallons of usable gas for the generator.
An Onan 4000 uses a half gallon per hour at half load.
So the generator should be capable of 84 hours (3.5 days) of run time, before you have to refuel.
So what size battery would be equivalent to replacing the generator?
50 kwh? I guess it could be smaller with more solar production (weather permitting)

No, I think it would be far worse than that.

If you assumed 4kW generator running 50%, then it’s making 2 kW of power. Over your assumed 84 hours, that’s 168 kWh, give or take.

Assuming inverter has 84% efficiency (picked that reasonable number to make numbers come out evenly), it would take 200 kWh of battery bank capacity.

Compared to 168 kWh from your generator, solar wouldn’t do much. To me it would be so insignificant that I wouldn’t bother with it UNDER THE CONDITIONS YOU DESCRIBED.



P.S. — As much as I would like to operate a large van camper solely from batteries, I understand the limitations fairly well. However, I think most buyers don’t and many of them who believe sales guys are going to be incredibly pissed when system performance is different than they expected based on what they were told.

[bry899]

Originally Posted by Chance

No, I think it would be far worse than that.

If you assumed 4kW generator running 50%, then it’s making 2 kW of power. Over your assumed 84 hours, that’s 168 kWh, give or take.

Assuming inverter has 84% efficiency (picked that reasonable number to make numbers come out evenly), it would take 200 kWh of battery bank capacity.

Compared to 168 kWh from your generator, solar wouldn’t do much. To me it would be so insignificant that I wouldn’t bother with it UNDER THE CONDITIONS YOU DESCRIBED.



P.S. — As much as I would like to operate a large van camper solely from batteries, I understand the limitations fairly well. However, I think most buyers don’t and many of them who believe sales guys are going to be incredibly pissed when system performance is different than they expected based on what they were told.

Thanks, its good to have direct comparison for Battery vs Generator at a higher usage.

[Chance]

Personally, I see requirement for a conventional generator limited to meeting two needs:

1) Power air conditioner(s) for extended periods.

2) Charge batteries.


I can’t think of anything else right now that can’t be done effectively in other ways without having a conventional “Onan-type” generator, or even a portable generator for that matter. Everything else should use so little energy that it can be met with solar and/or alternator charging of batteries to power an inverter.

How one uses the RV makes a huge difference to those two items. Unless I’m missing other requirements, it mostly comes down to air conditioning.

[Chance]

Originally Posted by bry899

Thanks, its good to have direct comparison for Battery vs Generator at a higher usage.

By the way, if one was designing smaller rigs limited to one air conditioner, and owner was going to boondock in hot weather where he/she was going to run generator continuously for days as in your example above, I would look at the highest efficiency A/C with soft start, and go with an Onan 2800i inverter generator instead of a 4,000 Watt Onan. Efficient A/Cs pull less than 1,400 Watts on average, so generator could run around 50%, burning much less fuel. And it would be much quieter too. Based on Onan data, a small RV may only burn around 0.2 gallons per hour.

[bry899]

Originally Posted by Chance

By the way, if one was designing smaller rigs limited to one air conditioner, and owner was going to boondock in hot weather where he/she was going to run generator continuously for days as in your example above, I would look at the highest efficiency A/C with soft start, and go with an Onan 2800i inverter generator instead of a 4,000 Watt Onan. Efficient A/Cs pull less than 1,400 Watts on average, so generator could run around 50%, burning much less fuel. And it would be much quieter too. Based on Onan data, a small RV may only burn around 0.2 gallons per hour.

Thanks again for the info. That all makes sense.
Both the generator and the rooftop air conditioning are way too loud for us.
By the way, we do very little camping in the summer, we like to avoid the heat and crowds and traffic so most of our travels are Spring and Fall.

[The_Breeze]

Originally Posted by Chance

Are your panels rated at 1,300 Watts (325 each) or are you actually “producing” 1,300 Watts?

Assuming it’s standard “rated” capacity, you could get about 4,000 Watt-hours daily on sunny days — significantly more if parked in desert in summer. Anyway, your 400 Ah battery bank represent around 5,000 Watt-hours, so on sunny days you can discharge them pretty low and still charge them back up.

Now, let’s look at vans and small motorhomes with no generator which have greater battery capacity and must rely on them for air conditioning. The Cross Trek has 800 Ah of battery, which is about 10,000 Watt-hour (10 kWh).

It comes with up to 380 Watt solar as option, which should make about 1,200 Watt-hours daily. If you ran air conditioner all day or night so as to drain battery bank pretty low, it would take a week of solar at 1,200 Watt-hours daily to make 8,400 Watt-hours; assuming average sunny days for entire week, and that you don’t park in shade.

Just saying that when design goal is to go without a conventional generator, we need a lot faster way to charge batteries. And the faster that system can charge the massive battery bank, the less critical solar contribution becomes.

Panels are rated at 325 (2 in series to form an array [650], 2 arrays in parallel [1300]). 1300w capable. I like the way you introduced watt hours, using the possible actual output based on exposure.

The series/parallel fails if both arrays are covered by shade. If one is exposed. It functions to the degree its exposed. Part of the reason I'm not willing to part with the generator yet.

"And the faster that system can charge the massive battery bank, the less critical solar contribution becomes". No question there and understand the quest much more now. Thanks.

[kwplot34]

We dry camp quite a bit and will stay out for up to 8 days, I have a Yamaha 2000 inverter generator that we take along to power the rv for charging batteries, watch a movie etc. At night I let it run because of the residential fridge. On an 8 day trip it uses about 4 gallons of gas. Seems like a lot less work, money and maintenance to just use a small generator than all of these solar panels, expensive big, heavy battery banks. Ours is wired for solar and i will install a panel this year, but i'm not going to leave the generator behind.

[Chance]

Originally Posted by kwplot34

We dry camp quite a bit and will stay out for up to 8 days, I have a Yamaha 2000 inverter generator that we take along to power the rv for charging batteries, watch a movie etc. At night I let it run because of the residential fridge. On an 8 day trip it uses about 4 gallons of gas. Seems like a lot less work, money and maintenance to just use a small generator than all of these solar panels, expensive big, heavy battery banks. Ours is wired for solar and i will install a panel this year, but i'm not going to leave the generator behind.

Agree generators are an inexpensive way to generate significant electrical power for extended periods; provided they are allowed of course. I use a similar 2200/1800 Watt unit to power small air conditioner when boondocking in summer and fall, and even though it is not allowed, the rule isn’t enforced. At least not yet.

Having said that, I’m curious why you need to run a generator overnight at all to power the refrigerator?

You have a very nice and expensive motorhome, yet it sounds like your batteries can’t power the residential fridge through the night. Regardless of how little gas your portable inverter generator uses, that doesn’t seem right.

Your motorhome specs show you have a built-in diesel generator that can power two air conditioners and probably anything else like microwave at same time, but is probably too large to efficiently power TVs or a residential fridge on a continuous basis. No doubt a smaller generator is a better match if a few hundred Watts of electricity is all that is required continuously. When you’re only using 4 gallons of gas over 8 days, on average that portable generator is not being loaded down very much at all; which makes sense but also begs a question.

Isn’t that what RV batteries are for? Specs show your motorhome comes with 2 batteries standard, and space for 2 more. I may be wrong, but if you had 4 quality batteries, would you need to run a generator all night? Unless you like generator noise in background (and some do), I’d first investigate why batteries can’t power fridge overnight.

Seems that adding solar may not help much short-term if batteries can’t power fridge through the night and you end up running portable generator anyway.

[kwplot34]

Originally Posted by Chance

Agree generators are an inexpensive way to generate significant electrical power for extended periods; provided they are allowed of course. I use a similar 2200/1800 Watt unit to power small air conditioner when boondocking in summer and fall, and even though it is not allowed, the rule isn’t enforced. At least not yet.

Having said that, I’m curious why you need to run a generator overnight at all to power the refrigerator?

You have a very nice and expensive motorhome, yet it sounds like your batteries can’t power the residential fridge through the night. Regardless of how little gas your portable inverter generator uses, that doesn’t seem right.

Your motorhome specs show you have a built-in diesel generator that can power two air conditioners and probably anything else like microwave at same time, but is probably too large to efficiently power TVs or a residential fridge on a continuous basis. No doubt a smaller generator is a better match if a few hundred Watts of electricity is all that is required continuously. When you’re only using 4 gallons of gas over 8 days, on average that portable generator is not being loaded down very much at all; which makes sense but also begs a question.

Isn’t that what RV batteries are for? Specs show your motorhome comes with 2 batteries standard, and space for 2 more. I may be wrong, but if you had 4 quality batteries, would you need to run a generator all night? Unless you like generator noise in background (and some do), I’d first investigate why batteries can’t power fridge overnight.

Seems that adding solar may not help much short-term if batteries can’t power fridge through the night and you end up running portable generator anyway.

I only have 2 6V batteries in it right now need to add 2 more along with the solar panel, it is on the list of things to do before we head back out this year. The RV does have a big diesel generator that will power the 2 ac's and all of the other electrical appliances and we don't usually need it while boon docking in the mountains, so the small generator is used instead. There really is not much of any load on it and we do like to sleep with a fan so the generator runs at night. Will the refrigerator run all night on the batteries? I don't know, never tried it. But the batteries hold up well while we are out all day trail riding and fly fishing, I do set the AGM just in case.

[Chance]

This information is from Thor Tranquility flyer posted by gw5815.

It breaks down what the Thor Re(Li)able lithium package includes and what it replaces.

As a side note, whoever is supplying and/or checking technical information has no clue about proper units of measure. Thor has been the worst I’ve noticed. I’m pretty sure they mean 11,000 Wh of energy, not 11,000 kW of power.
.

[JamieGeek]

Originally Posted by Chance

This information is from Thor Tranquility flyer posted by gw5815.

It breaks down what the Thor Re(Li)able lithium package includes and what it replaces.

As a side note, whoever is supplying and/or checking technical information has no clue about proper units of measure. Thor has been the worst I’ve noticed. I’m pretty sure they mean 11,000 Wh of energy, not 11,000 kW of power.
.

LMAO! Yup that is pretty bad. I usually see people messing up just Wh vs W units but that goes for the gusto and mess up the whole magnitude thing too.