Gobi Sienna Heating with Bluetti and External Batts

[sshibly]

Good Monday Morning from West Michigan,

Grandma and I are planning on hitting the piers for some spring fishing, I bought an old (2013) sienna awd to fish.

I want to run a 300w small heater in the van for heat.

The setup will be simple

Heater > Bluetti

Bluetti Solar input > 36/48v external battery that will charge the bluetti


Connecting Bluetti to external battey

What is the best practice to connect the batt to the bluetti?

Max charge rate is 700w, so 15A is the max current, I am guessing with lower volts like 40v I will see max charge rate of 450w or so.

Q1. Do I add an inline fuse?
Q2. Do I add an inline switch, like a circuit breaker like the ones in the EG4 batts?

 

[Dave in AZ]

Good Monday Morning from West Michigan,

Grandma and I are planning on hitting the piers for some spring fishing, I bought an old (2013) sienna awd to fish.

I want to run a 300w small heater in the van for heat.

The setup will be simple

Heater > Bluetti

Bluetti Solar input > 36/48v external battery that will charge the bluetti


Connecting Bluetti to external battey

What is the best practice to connect the batt to the bluetti?

Max charge rate is 700w, so 15A is the max current, I am guessing with lower volts like 40v I will see max charge rate of 450w or so.

Q1. Do I add an inline fuse?
Q2. Do I add an inline switch, like a circuit breaker like the ones in the EG4 batts?

Your question is confusing, because I think you are using the ">" sign wrong, the reverse of what the world uses...
Heater > Bluetti means heater goes into or supplies the bluetti. You probably meant
Bluetti > heater

and I guess you really mean:
Bluetti Solar input < 36/48v external battery that will charge the bluetti.

So: 48v battery --> supplies the--> bluetti solar input (15A or 700W max), --> which supplies the --> 300W heater.

Q1. Inline fuse. The heater will have its own cb/ overtemp protection, and I expect is 120v plugged into bluetti. The bluetti 120v port is protected, and 300w 120v is tiny 2.5A , so the heater cord is OK.
Q2. Inline switch. Yes. If you are connecting an external battery, you need to protect the wires from the battery to the bluetti. Also, you should always have a switch to disconnect battery power without getting wrenches out to disconnect terminals--that is how battery shorts/arcs happen. However, you could just plug and unplug the battery supply cable from the bluetti solar input port as your "switch". That still leaves a fuse or cb to protect those cables, so I would just get a dc circuit breaker to do both. 48v, 700W max, means 14.5A max. You need to use cables capable of 125% that load, so 19A. So 14 AWG minimum, 12AWG better. Then you fuse at 125% of the cable to protect it, or the load to protect both cable and load (bluetti). The bluetti is actually already protected, it shuts off or throttles any input above 15A or 700W. But I'd put a cb switch in there for 20A to 25A. The only real utility is having an on off sw so you don't have to unplug the battery and have a hot battery cable flopping around.

Have you actually tested a 300W heater? That isn't enough to warm up one foot! I have a small heater I use to warm my feet under my desk in winter, so house is 70f and it's a small space for my legs, at the 1000W setting I barely think it is good enough...

of course, the actual Watt-hrs size of your Bluetti and external battery are the critical numbers for your plan, how much heat for how long, and you neglected to give those two critical pieces of info...

I hate to say it, but by far your better plan is to buy a Chinese diesel heater for $100, which will put out 5000kW, and hold the energy of 15 big batteries in a small diesel tank. Just plug it into your Bluetti and get some actual heat, from the device actually engineered to provide heat. Millions of truckers have gone before you and figured out that it is the best way to heat a vehicle cab when engine is off, and use them every night. Why would you want to ignore to already proven and tested solution to car heating, for $100 total, and invent your own super weak heating answer?

 

[sshibly]

and I guess you really mean:
Bluetti Solar input < 36/48v external battery that will charge the bluetti.

So: 48v battery --> supplies the--> bluetti solar input (15A or 700W max), --> which supplies the --> 300W heater.

Q1. Inline fuse. The heater will have its own cb/ overtemp protection, and I expect is 120v plugged into bluetti. The bluetti 120v port is protected, and 300w 120v is tiny 2.5A , so the heater cord is OK.
Q2. Inline switch. Yes. If you are connecting an external battery, you need to protect the wires from the battery to the bluetti. Also, you should always have a switch to disconnect battery power without getting wrenches out to disconnect terminals--that is how battery shorts/arcs happen. However, you could just plug and unplug the battery supply cable from the bluetti solar input port as your "switch". That still leaves a fuse or cb to protect those cables, so I would just get a dc circuit breaker to do both. 48v, 700W max, means 14.5A max. You need to use cables capable of 125% that load, so 19A. So 14 AWG minimum, 12AWG better. Then you fuse at 125% of the cable to protect it, or the load to protect both cable and load (bluetti). The bluetti is actually already protected, it shuts off or throttles any input above 15A or 700W. But I'd put a cb switch in there for 20A to 25A. The only real utility is having an on off sw so you don't have to unplug the battery and have a hot battery cable flopping around.

Have you actually tested a 300W heater? That isn't enough to warm up one foot! I have a small heater I use to warm my feet under my desk in winter, so house is 70f and it's a small space for my legs, at the 1000W setting I barely think it is good enough...

of course, the actual Watt-hrs size of your Bluetti and external battery are the critical numbers for your plan, how much heat for how long, and you neglected to give those two critical pieces of info...

I hate to say it, but by far your better plan is to buy a Chinese diesel heater for $100, which will put out 5000kW, and hold the energy of 15 big batteries in a small diesel tank. Just plug it into your Bluetti and get some actual heat, from the device actually engineered to provide heat. Millions of truckers have gone before you and figured out that it is the best way to heat a vehicle cab when engine is off, and use them every night. Why would you want to ignore to already proven and tested solution to car heating, for $100 total, and invent your own super weak heating answer?

Dave, you correct, external batts will feed into solar input for the Blue

I am using 10 awg wire, the run is about 4 ft max.

I will look for a 20A~25A CB,

The sienna is tiny compared to my 350 Transit Van (extra high), so a little bit of heat will go a long way. I will have air gap insulation on the front and rear windows and possibly bubblewrap in the side windows.

We will be in winter gear for pier fishing and raising the inside temp 5f to 10f will be enough to make is comfy as we don't want to take off the core winter clothing layers, just the glove and parka comes off.

I love those diesel heaters, actually suggested one to a guy who ice fishes in a shanty with a bunk bed in it. But the sienna is tight.

I have 2 bluettis

AC200P
AC70

I bought the AC 70 as it is much lighter and I hurt my wrist few months back. It has max charge input of 500W for solar, so I could heat max 500W and keep going.
I have 8kw of external battery and making another 2.8kw with my topband 25ah cells I bought many moons back.

it was been abnormally NOT here in MI, when we are back to our 30s during the day and 20s at night, I will do a dry run in the sienna.

I used the AC200P in the transit van, when it was low 40s outside, the van was UN-insulated, with a 430w heater running continuously, we were able to sleep in the van and after 4.6 hours the bluetti died, man was it cold in the van. that was last year during salmon season, pic of my first salmon of last year attached.

 

[Dave in AZ]

Dave, you correct, external batts will feed into solar input for the Blue

I am using 10 awg wire, the run is about 4 ft max.

I will look for a 20A~25A CB,

The sienna is tiny compared to my 350 Transit Van (extra high), so a little bit of heat will go a long way. I will have air gap insulation on the front and rear windows and possibly bubblewrap in the side windows.

We will be in winter gear for pier fishing and raising the inside temp 5f to 10f will be enough to make is comfy as we don't want to take off the core winter clothing layers, just the glove and parka comes off.

I love those diesel heaters, actually suggested one to a guy who ice fishes in a shanty with a bunk bed in it. But the sienna is tight.

I have 2 bluettis

AC200P
AC70

I bought the AC 70 as it is much lighter and I hurt my wrist few months back. It has max charge input of 500W for solar, so I could heat max 500W and keep going.
I have 8kw of external battery and making another 2.8kw with my topband 25ah cells I bought many moons back.

it was been abnormally NOT here in MI, when we are back to our 30s during the day and 20s at night, I will do a dry run in the sienna.

I used the AC200P in the transit van, when it was low 40s outside, the van was UN-insulated, with a 430w heater running continuously, we were able to sleep in the van and after 4.6 hours the bluetti died, man was it cold in the van. that was last year during salmon season, pic of my first salmon of last year attached.

So, that's 2000 and 768 Watt-hrs. Just a normal weak hair dryer is 1000W, that's just 2.4 hrs runtime or so! Decent ac200p power station, and a 48V battery will be a sizeable increase.

I don't mind chatting about it if you still want to use battery, in fact my Pecron e1500LFP has a 700W 32-95V solar input too, as well as a 100W 11-18V one, and I have made several videos in last 2 weeks showing charging the thing through these ports from external batteries, to use them as cheap "extension battery". Pretty much exactly what you are wanting to do.

Here is one using small heater to drain, then refilling from a 100Ah battery via solar inputs:

Yesterday I made a video using tacoma truckbed inverter outlet and a power supply to go from 120v to 60V and 5A, and charge via the 700W solar input. And I've got a 3072 Watt-hrs actual extension battery too, which is 48V (but plugs into dedicated extension port, not the solar input).

And numerous videos on insulating a Sienna-sized truckbed camper to stay warm.

Yesterday I needed to drain my 1500 Watt-hrs power station, so I could do a test charging it up from Tacoma truckbed inverter. Thinking of you, I climbed in back of camper, 65f in Phoenix with cloud cover. Ran heater at 1000W. Drained this pretty large ppower tation to 70% in 30 min or so. No way I'd want to use that fishing in the cold!

As for running 400W solar panels to then power a space heater... if it's sunny enough to power the panels, you get way more than 400W of heat by just parking the van in the sun in the first place, at a massively more efficient level!

Sorry, but solar will never remotely come close to chemical storage (diesel, propane) for heat. Especially if you are using a small setup.

You said you're familiar with diesel heaters, why exactly are you not just buying one for $100 and running it off your AC70. If you're worried it will be too much heat,
Run it on level 1 then. You will never regret having too much heat available if needed! Ignoring the premade solution that everyone trying to heat a parked car or truck uses--diesel parking heaters-- just seems like a waste of time and $$$ to arrive at a solution 1% as good.

Just having spent countless hours and reading on heating small space, along with power stations and extension batteries, I hate to see you skip what is the overwhelming solution, to me

Best regards.

 

[sshibly]

So, that's 2000 and 768 Watt-hrs. Just a normal weak hair dryer is 1000W, that's just 2.4 hrs runtime or so! Decent ac200p power station, and a 48V battery will be a sizeable increase.

I don't mind chatting about it if you still want to use battery, in fact my Pecron e1500LFP has a 700W 32-95V solar input too, as well as a 100W 11-18V one, and I have made several videos in last 2 weeks showing charging the thing through these ports from external batteries, to use them as cheap "extension battery". Pretty much exactly what you are wanting to do.

Here is one using small heater to drain, then refilling from a 100Ah battery via solar inputs:

Yesterday I made a video using tacoma truckbed inverter outlet and a power supply to go from 120v to 60V and 5A, and charge via the 700W solar input. And I've got a 3072 Watt-hrs actual extension battery too, which is 48V (but plugs into dedicated extension port, not the solar input).

And numerous videos on insulating a Sienna-sized truckbed camper to stay warm.

Yesterday I needed to drain my 1500 Watt-hrs power station, so I could do a test charging it up from Tacoma truckbed inverter. Thinking of you, I climbed in back of camper, 65f in Phoenix with cloud cover. Ran heater at 1000W. Drained this pretty large ppower tation to 70% in 30 min or so. No way I'd want to use that fishing in the cold!

As for running 400W solar panels to then power a space heater... if it's sunny enough to power the panels, you get way more than 400W of heat by just parking the van in the sun in the first place, at a massively more efficient level!

Sorry, but solar will never remotely come close to chemical storage (diesel, propane) for heat. Especially if you are using a small setup.

You said you're familiar with diesel heaters, why exactly are you not just buying one for $100 and running it off your AC70. If you're worried it will be too much heat,
Run it on level 1 then. You will never regret having too much heat available if needed! Ignoring the premade solution that everyone trying to heat a parked car or truck uses--diesel parking heaters-- just seems like a waste of time and $$$ to arrive at a solution 1% as good.

Just having spent countless hours and reading on heating small space, along with power stations and extension batteries, I hate to see you skip what is the overwhelming solution, to me

Best regards.

Dave,
No solar panels,
I will be using the bluetti with external battery plugged in into the solar input.
I have an 8KW battery bank and adding another 3kw battery if needed.

In both the sienna and transit:
Primary source of heat, if I want to sit in my jam jams, will be to idle the vehicle and use the vehicles heat.

I am a Michigander, which is in American Indian (Odawa) word that means - crazy winter fishermen who are out fishing in subzero temps.

Grandma is nearly 80 yrs young, here she is fishing at Muskegon, the air temp was around 26F and wind was blowing at 10 knots.


You mentioned your truck bed, that is how I started, I bought a brand new Duramax diesel (long bed, CC) and I quickly realized that my chunky behind is not able to get up and down the bed easily. So I started looking at vans.

The mods I will be doing to the sienna will be to add insulation (air gap) to the windows and extra tint.

I plan on running the bluetti powered heater in the van while out fishing,

Bluetti internal batt + external = 8 hours of heat min

Diesel Heater Story:
Back in the day when I bought my duramax diesel truck, I lookup diesel APUs for electric source. Cheapest I found was $10k. And diesel heaters where around 1.5k.

With lithium batts and solar, 10kw of batt will be light and provide enough juice for most people.

For me, if it gets cold, I press my remote start button on key fob.

Are you camping in your tacoma bed? what mods have you done to it?

 

[Dave in AZ]

@sshibly
Yeah the diesel heaters used to be expensive when just Eberspacher and Webasto made them, but now these Chinese clones are almost perfect clones, for $100.

I do my hunting up in Michigan, near Alpena, so am pretty familiar with sitting in a shack heating it a bit Have done some ice fishing there too, and in AK. Good on your 80y.o. mom!
Yep, camping in truck bed. Here is a quick 1.5 min video showing my insulation of canopy camper popup, might be useful for your Sienna insulation. I would use this stuff for a Sienna also, or my own Odyssey if I insulated it.

 

[sshibly]

Dave,
where did you find that shiny insulation? I bought the one from lowes and it is the bubble type, also which velco is that, looks like it was strong adhesive on it, nice, I like it.

I am going to double tint the windows and then put that shiny insulation but I will spray paint it black and the shiny windows stick out and MI DNR keeps bugging grandma to remind her that no camping is allowed.
Grandma take a break every hour or so to warm up, drink some coffee, take a break etc.

oh man, pop up truck bed campers rock, that is my first love, gosh, it has been a while but I still have mine, don't use it :-(.

No way, small world, awesome, they have good hunting on the east side. that is a haul from all the way from west coast. pls give me shout, if you driving by close to me (49506).

The front window is huge in both the sienna and transit , so along with front window foldout insulation I am adding a ceiling to floor curtain that will hold the cold air in that space, the top of the curtain will be velcro'd to roof liner


Bluetti:
My strategy to bluetti AC70 for 10 hours of heat depends on it being able to provider 300w and charge at 300w plus simultaneously. I have to do some dry run at home this weekend.

I am going to peek at amazon for the 20a Circuit breaker

 

[Dave in AZ]

Velcro, works well. Just bought 2nd roll.
SOURRI 1 Inch x 82 Feet Hook and... https://www.amazon.com/dp/B0CNJTK2JP?ref=ppx_pop_mob_ap_share

Insulation from US Energy, 5mm closed cell foam w double foil, WAY more insulation R than reflectix. Used for ducts. They have different roll lengths and widths, browse around.
US Energy Products R-8 HVAC Duct Wrap Insulation Reflective Double Sided Foam Core (Class 1-A ASTM FIRE Rated) (AD5 1/4INCH Thick) (4ft x 50ft) https://a.co/d/gdTyFLL

 

[HarryN]

Those portable power stations are typically built with Li batteries. When the temps go below 0 F, most of them will not be able to discharge and none will be able to charge much below freezing.

 

[Dave in AZ]

Those portable power stations are typically built with Li batteries. When the temps go below 0 F, most of them will not be able to discharge and none will be able to charge much below freezing.

This is true, however here are the specs for his bluettis
Ac70 charge 32 to 104f, discharge to -4f
Ac200p operate 32-104f, storage 14-113f. So can't even discharge below freezing.

So yeah, would need to be inside house to charge, and kept warm to discharge to run heater. This for sure will cause you difficulties, 300w isn't enough heat to warm them and you bith, I doubt. Remember the old 100W light bulbs, 3 of them wouldn't warm a car...

 

[sshibly]

Velcro, works well. Just bought 2nd roll.
SOURRI 1 Inch x 82 Feet Hook and... https://www.amazon.com/dp/B0CNJTK2JP?ref=ppx_pop_mob_ap_share

Insulation from US Energy, 5mm closed cell foam w double foil, WAY more insulation R than reflectix. Used for ducts. They have different roll lengths and widths, browse around.
US Energy Products R-8 HVAC Duct Wrap Insulation Reflective Double Sided Foam Core (Class 1-A ASTM FIRE Rated) (AD5 1/4INCH Thick) (4ft x 50ft) https://a.co/d/gdTyFLL

Thanks!

 

[sshibly]

This is true, however here are the specs for his bluettis
Ac70 charge 32 to 104f, discharge to -4f
Ac200p operate 32-104f, storage 14-113f. So can't even discharge below freezing.

So yeah, would need to be inside house to charge, and kept warm to discharge to run heater. This for sure will cause you difficulties, 300w isn't enough heat to warm them and you bith, I doubt. Remember the old 100W light bulbs, 3 of them wouldn't warm a car...

FYI: BOTH Bluetti's have the same LFE chemistry
they have is temp range on the website:

• Q10: Can I use or charge AC180 in sub-zero temperatures?​

  
  A:
  You can use the AC180 to power your devices in cold weather, but please avoid recharging it below freezing.
  The operating temperature ranges for AC180 are:
  Charging: 0℃-40℃/32℉-104℉
  Discharging: -20℃-40℃/-4℉-104℉

 

[Dave in AZ]

FYI: BOTH Bluetti's have the same LFE chemistry
they have is temp range on the website:

• Q10: Can I use or charge AC180 in sub-zero temperatures?​

  
  A:
  You can use the AC180 to power your devices in cold weather, but please avoid recharging it below freezing.
  The operating temperature ranges for AC180 are:
  Charging: 0℃-40℃/32℉-104℉
  Discharging: -20℃-40℃/-4℉-104℉

You don't have an ac180, and it doesn't matter squat that the battery chemistry is the same. No lifepo4 can be charged below freezing, yes, but the DISCHARGE doesn't depend on the chemistry, it depends on that particular power station BMS, battery mgt system, and whatever temperature limiter they wired and coded into the control motherboard.

I copied the info for your actual two devices, directly from their official specifications sheets for those two. Ac200p may actually have a discharge spec the same as ac70, but it doesnt list it on specs sheet, just gives "operating temperature ", which makes me think they just installed a single temp sensor and cutoff and use it for both charge and discharge enabling.
The ac200, ac200max, ac200p, ac200L are all different versions with different specs as they cut features for cost savings...

By the way, it is very common for different models to have quite different lower temp discharge limits. I have a buddy who had a goalzero 1500x, a Jackery 500, and a Pecron300. In that cold snap in Jan, he could not start his diesel heater in Colorado, -5f, because the goalzero and Jackery both were temperature disabled by their BMS. But the Pecron has a lower limiter on it's design, and allowed him to get his heater started, which let him warm up the other 2 power stations. His goalzero wouldn't start working until above 33f.

 

[sshibly]

You don't have an ac180, and it doesn't matter squat that the battery chemistry is the same. No lifepo4 can be charged below freezing, yes, but the DISCHARGE doesn't depend on the chemistry, it depends on that particular power station BMS, battery mgt system, and whatever temperature limiter they wired and coded into the control motherboard.

I copied the info for your actual two devices, directly from their official specifications sheets for those two. Ac200p may actually have a discharge spec the same as ac70, but it doesnt list it on specs sheet, just gives "operating temperature ", which makes me think they just installed a single temp sensor and cutoff and use it for both charge and discharge enabling.
The ac200, ac200max, ac200p, ac200L are all different versions with different specs as they cut features for cost savings...

By the way, it is very common for different models to have quite different lower temp discharge limits. I have a buddy who had a goalzero 1500x, a Jackery 500, and a Pecron300. In that cold snap in Jan, he could not start his diesel heater in Colorado, -5f, because the goalzero and Jackery both were temperature disabled by their BMS. But the Pecron has a lower limiter on it's design, and allowed him to get his heater started, which let him warm up the other 2 power stations. His goalzero wouldn't start working until above 33f.

Sorry, I should have stated, they call have the same specs on bluetti's FAQ.

Good Point, I have not tested mine at 32 F,

No lifepo4 can be charged below freezing

You sure? from I what I have read, the battery makes spec out this, A123 for example were made for the DOD and have better ranges

yes, not knowing what the hardware is set to, I probably need to get confirmation from bluetti.

Anyone want to place bets on the temp range for discharge for AC200P?

 

[HarryN]

Here is what I know - I built my own portable power stations. I grew up in the mid west and spent a night on the road where it hit ( -30 F) in IA and absolutely nothing worked right. That experience has stuck with me 40 years later.

So when I built my own power stations, I built both of them with components that are actually rated for very cold weather option, not just storage temperatures. One of them has Lifeline AGM batteries wired 2S - 24 volts so it will work in some very tough conditions. The other one has 2 battleborns in it and I use their ratings for what most Li batteries can handle. (right or wrong ). Obviously that one is limited by the battery temp specs.

Most power station and battery specs on the market are still very optimistic.

 

[sshibly]

Agree, sub zero BATT temps are no good.

My use case:
Batts stored in heated garage, stays at 50F in peak winter,
Van driven with heat on to fishing destination, batts remain in the van at room temp
once at fishing spot, the heat from batts will run continuously for say 8 to 10 hours.
So the batts NEVER go below 50F, the joys of vanlife ;-)

I saw a video on youtube where a hours in BC can be heated with a hair dryer (same about of heat), lol

 

[sshibly]

update:
I tested charging/discharging simultaneously, it worked well

348w in, 230w out, not bad, I will server my needs for Sienna, it is unseasonably warm in MI this spring, so I have not had a need to use this yet.