myles
Autonomy Expert
- Joined
- Jan 24, 2021
- Messages
- 289
Hey All
Other than the fact that running 120V from inverter is less efficient than running direct from battery....
what are the thoughts on this style heater underneath a 1/4" aluminum plate that would be under all the batteries in an insulated box?
The I would use this to control the heater, I currently use this on my hot water tank to force a recirc pump to come on when it has hit full temp and is running on sol ark smart loading only.
Reason for use of 120v, 48V buck converters are prone to failure, 12V in series would work as well...BUT complexity of having it shut off when inverter shuts off is a waste of space and brain work. I want the batteries to shut OFF to save the batteries when voltages dip too low, JK BMS would kill power to the pack when they get cold. hard to find heating matts that are as simple as this and run at a lower temp, we want to warm cells slow not bake them. I only need to keep the cells around 5*C, and they are stored in an off grid setup in a insulated crawl space that only gets to around -2*C
Failsafes: When inverter cutoff voltage reached, heaters shut off (to not drain battery any more), batteries start to cool, when batteries get too cool, JK BMS shuts down as well, then entire system stays dormant until we would arrive next at the cabin, startup Generator to inverter, this will allow warming up the cells, then when cells warm enough batteries back online safely.
Solark smart load will be hooked up to crawl space heater so that if batteries full, preheat crawl space with excess solar!
Given the 560AH capacity of the pack, I suspect just running the inverter and heaters will take quite a while to drain down.
Inverter load: 75w idle (sol ark 12k, manual says 60w, I use 75w to be safe)
Heater load coming on and off: 20w*2 (safe numbers), projected 12 hours per day run time, likely over estimate given the highly insulated environment.
Starlink Load: set to schedule on for 4 hours during day to check in and snowmelt, then shut off. 400watt hours
6KW bifacial solar panels facing south at at least 70 degree angle for snow melt.
Parasitic draw per day: 1.8 kwh inverter + 0.48kwh+ 0.4kwh star link
Other than the fact that running 120V from inverter is less efficient than running direct from battery....
what are the thoughts on this style heater underneath a 1/4" aluminum plate that would be under all the batteries in an insulated box?
The I would use this to control the heater, I currently use this on my hot water tank to force a recirc pump to come on when it has hit full temp and is running on sol ark smart loading only.
Reason for use of 120v, 48V buck converters are prone to failure, 12V in series would work as well...BUT complexity of having it shut off when inverter shuts off is a waste of space and brain work. I want the batteries to shut OFF to save the batteries when voltages dip too low, JK BMS would kill power to the pack when they get cold. hard to find heating matts that are as simple as this and run at a lower temp, we want to warm cells slow not bake them. I only need to keep the cells around 5*C, and they are stored in an off grid setup in a insulated crawl space that only gets to around -2*C
Failsafes: When inverter cutoff voltage reached, heaters shut off (to not drain battery any more), batteries start to cool, when batteries get too cool, JK BMS shuts down as well, then entire system stays dormant until we would arrive next at the cabin, startup Generator to inverter, this will allow warming up the cells, then when cells warm enough batteries back online safely.
Solark smart load will be hooked up to crawl space heater so that if batteries full, preheat crawl space with excess solar!
Given the 560AH capacity of the pack, I suspect just running the inverter and heaters will take quite a while to drain down.
Inverter load: 75w idle (sol ark 12k, manual says 60w, I use 75w to be safe)
Heater load coming on and off: 20w*2 (safe numbers), projected 12 hours per day run time, likely over estimate given the highly insulated environment.
Starlink Load: set to schedule on for 4 hours during day to check in and snowmelt, then shut off. 400watt hours
6KW bifacial solar panels facing south at at least 70 degree angle for snow melt.
Parasitic draw per day: 1.8 kwh inverter + 0.48kwh+ 0.4kwh star link
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