CantStopTommy
New Member
- Joined
- Jan 22, 2022
- Messages
- 11
Hello,
Newbie here looking for feedback on my idea for powering an off-road camper trailer.
We're building this trailer for a planned ~6 month lap of Australia with our family of 4.
Guiding principles
- Be self-sufficient on PV alone - most similar setups seem under powered on PV and constantly require shore power and/or DCDC charging from the tow vehicle's alternator - don't want this!
- No AC loads - trying to avoid an inverter as we don't need it - i think 12v can power everything we actually need
- No dual battery setup in the tow vehicle - seems like a lot of expense that could be invested in the trailer instead
Calcs
Average Load (from my big spreadsheet)
1.05 kWh / day (88Ah/day)
Solar Power Required (assumes avg solar irradiance = 5hrs/day)
422W
Days of Autonomy
2 (Australia is pretty sunny!)
Battery Storage Required
2.1kWh (176Ah)
Required Charge Controller Capacity (assumes 500W of PV is used)
41.7 A
Planned System Specs
500W of solar panel/s
200Ah LiFePo4 battery
50A PV Charge controller (MPPT)
Lots of USB and Cigarette outlets
240V Battery Charger + extension cord for shore power if we need it (with charging profile for LiFePo4)
~500A capable jump start battery (in case we accidentally run down the start battery on the tow vehicle)
Q's for you!
- Does this setup make sense?
- Should I allow more headroom in the Charge Controller Spec in case I want (or need) to add more PV later
- If I use a nice BMS like the Overkill, do I still need a shunt to accurately monitor state of charge, etc?
- Should I build up my own battery from cells and Overkill BMS?
- If I build, are the Fortune cells worth it? (lots of corrugated dirt roads where we are going)
- What am I missing?
Any and all feedback will be much appreciated!
Cheers,
Tom
Newbie here looking for feedback on my idea for powering an off-road camper trailer.
We're building this trailer for a planned ~6 month lap of Australia with our family of 4.
Guiding principles
- Be self-sufficient on PV alone - most similar setups seem under powered on PV and constantly require shore power and/or DCDC charging from the tow vehicle's alternator - don't want this!
- No AC loads - trying to avoid an inverter as we don't need it - i think 12v can power everything we actually need
- No dual battery setup in the tow vehicle - seems like a lot of expense that could be invested in the trailer instead
Calcs
Average Load (from my big spreadsheet)
1.05 kWh / day (88Ah/day)
Solar Power Required (assumes avg solar irradiance = 5hrs/day)
422W
Days of Autonomy
2 (Australia is pretty sunny!)
Battery Storage Required
2.1kWh (176Ah)
Required Charge Controller Capacity (assumes 500W of PV is used)
41.7 A
Planned System Specs
500W of solar panel/s
200Ah LiFePo4 battery
50A PV Charge controller (MPPT)
Lots of USB and Cigarette outlets
240V Battery Charger + extension cord for shore power if we need it (with charging profile for LiFePo4)
~500A capable jump start battery (in case we accidentally run down the start battery on the tow vehicle)
Q's for you!
- Does this setup make sense?
- Should I allow more headroom in the Charge Controller Spec in case I want (or need) to add more PV later
- If I use a nice BMS like the Overkill, do I still need a shunt to accurately monitor state of charge, etc?
- Should I build up my own battery from cells and Overkill BMS?
- If I build, are the Fortune cells worth it? (lots of corrugated dirt roads where we are going)
- What am I missing?
Any and all feedback will be much appreciated!
Cheers,
Tom