Thought I would add this for others that might read this thread.
Apart from the correct rated cable sizing v load. I have always used Midi Fuses/Holders when running from battery to any kind of charger, DC-DC, solar etc. i.e. 30A or above. Then for distribution, a multi fuse block with blade fuses. (Correctly rated). Usually lower loads like 1-15A, i.e. car fridge, LED lights etc
Years ago, I had a couple of 30A inline blade fuse holders melt, likely the quality of the item. I also do not use thermal circuit breakers. If there is an issue that causes it to trip, when it self resets, it re-energises and trips again until “you” disconnect it or something melts.
I have option 2 ready to go, just need to wire it into my canopy. There is a good video on YouTube of someone doing the same thing as well, works fine.
Possibly a Q for Bluetti Support, or anyone else in the know.
As mentioned I have a 75Ah LiFePo4 Auxiliary in the rear of the 4x4 with its own internal 20A DC-DC charger. In the near future there will also be a 110W (nominal 12V) solar panel on the roof to charge this battery at the same time when driving. Given the solar charge will be at a lower voltage, I may well not get much charge from solar when driving, it’s more for when stopped to offset the Engel fridge/freezer load.
I have outputs from this battery that I can plug the car charger for the 180 into. I regularly see 14.4VDC from the 75Ah when driving on my Victron shunt app. My Q is;
Does the internal BMS in the 180 limit the current to 10 amps without damage if more is available and therefore give me up to 14.4 x 10 = 144 watts of nominal charge? Or do I need to limit the available current in some other way?
Yes, the AC180 has control of how many amps it draws. This is true for power stations and most loads in general. Will the AC180 pull a full 10 amps from 14.4 volts? Probably not. I think the MPPT charge controller will prefer a higher voltage.
Also, while the solar panel is nominal 12v, most have a VOC near 18 or higher (my 12v 100w renogy have a VOC of 22.5) and a Vmp around 15+ volts (my renogy are around 18+). The amps is probably between 5-7, lower than the 10 max, but you might give it a try since the MPPT might prefer the slightly higher voltage.
Thanks for that RGB. The setup I have in the 4x4 rear is all “plug n play”, primarily all Anderson plugs. The controller I am using is a spare 15A Hardkorr that came with my portable “crocskin” panels. It is PWM, but has a Lithium profile. At 110W there would be little benefit from using MPPT which is another purchase. As the controller has Anderson on the input and output it would be easy to unplug the panel and rout a cable to the AC180 as I already have a MC4 to Anderson adaptor cable.
Once the panel is installed I’ll test the input from the Aux BAT output and then the panel direct to the 180 to see which gives more.
The panel is mounted horizontal, specs are 21.6Voc, 17.8Vmp, 6.6Isc & 6.24Vmp. Over the years I’ve used flat mounted panels I’ve noted around a 20% loss compared to angle mounted panels. I’ll note the difference once tested, but might be several weeks as Xmas is on its way lol. From the Youtube vids I’ve watched it seems around 8 amps is the average at a nom 12V input.
Panels produce as low as 1% to 5% on cloudy grey Autumn / Winter days. Don’t rely on peak power to size your project. However, that’s free, daily power. Once you experience the magic of running devices on “no grid” energy, you become addicted.
LOL at least I see my hubby bit less as a weirdo now that I witness other people affected with the “solar virus” on this forum. He’d rather wrap himself in 2 blankets to work on his computer in a 14°C room rather than heating his office using grid power, to save whatever he harvests on a rainy day for an “off grid” work day…
I was out in September, at times I was getting around 25 amps from all 3 panels. My caravan has a Projecta PM300 management system, it will take up to 50VDC solar. The 160W on roof and 2 x 150W hardkorr panels would exceed 50V in series, so are connected in parallel. I used some term blocks to rewire the on roof thru a 2pole 15A circuit breaker to isolate the roof panel if it is in shade. I then wired an Anderson under the van floor to those term blocks. I also made a couple of 2 into one Anderson patch leads, 1 wired in series the other in parallel. Also have a Anderson to MC4 patch lead.
This allows me to connect the Hardkorrs in either series or parallel to the caravan or use them to charge either my AC200P or AC180 in series for the higher voltage.
On average days of overcast, I still see 12-15 amps from all 3 panels in parallel to the caravan. If the sun aint shining, I have the option of hooking up the car via an extension lead to the van as I also fitted a 25Ah Redarc DC-DC. The Projecta PM300 although Lithium profile, is a VSR and with a smart alternator, not good enough.
The way I set up for off grid caravanning or charging the Bluetti in the event of a power outage is “Redundancy”.
However, there is a limit on what can be reasonably carried.
Caravan - I go totally off grid, no longer carry a generator as it is noisy, and there is a need to carry petrol to run it. My 4x4 and heater in the van are both diesel, much safer to carry. I charge from solar whenever I can, but have the option to charge from my car at 25 amps as well. I have 200Ah of LiFePo4 in the van and that gives me close to 4 days with no charge at all and more with solar/car charging. I’ve never run out of ‘juice’.
At home - I could run the genny (Honda 2kVA) to charge the Bluettis if the grid goes down for a long time. Plus get the Hardkorrs from the van.
There is a logical method in all of this. #1 item to have for off grid power, is a management system so you know what you are using and charging, don’t rely on a simple voltmeter especially for Lithium batteries. They have a very stable flat voltage curve. #2 I have 5 times battery capacity on board to what my average daily use is. (40Ah = approx 500Wh. #3 A solar array that is in Watts close to the Wh used. (I have 460W of panel for my 500Wh of use and the option of adding another 150W if I need to)
Added to this I have the AC180 capacity. It’s primary use in the van is to run the microwave, but I can charge my electric toothbrush, mobiles and laptops as well. Apart from the m/wave, I can do all of that from the van batteries as well = Redundancy.
I learned the hard way years ago that if you only have one source or charging method and it goes wrong trips can be at least cut short or ruined all together.
Had a rethink re car charging. I have in my arsenal a 37W Victron Inverter. I’ve noted that the AC180, when charged in silent mode regularly draws 280W (240VAC). Given the efficiency loss of an inverter I calculate that the DC current draw of the Victron will be approx 28A. As my Auxiliary battery is on a 40A 8AWG cable from under the hood it is more than enough to use to run the Victron either direct from the vehicle or alternatively from the Aux battery, when driving. I know it’s not the most efficient, but 280W of AC input is as good as if not better than what I might get with a DC converter and I already have the gear.
Definitely the cheaper way to go. I have several step up DC to DC converters which are capable of delivering the full 500 watt input charge rate (12-48 volt) so it is possible to increase if you ever have a need to do so. Increasing charge rates also mean increasing wiring size and having a cooling fan to supplement the DC step up converter.
That my 375W Victron will supply the 280W to the AC180 is enough for me, as I calculate may daily use will be <500Wh.
Breakfast - boil water for a coffee, 1,000W kettle = 100Wh and electric toaster = 80Wh. Total = 180Wh.
Lunch (if used) - Toasty Sandwich maker = 100Wh
Dinner (if used) - Microwave approx = 140Wh + another coffee = 80Wh. Total = 240Wh
Daily total approx 420Wh, at 280W input = < 2 hrs to charge from the Victron and I have 110W of solar I can plug in when not driving.
That sounds like a long-term wise solution. I think I would trust the Victron inverter for long term heavy duty use more than I would Noname step up converter’s
