We recently had a customer who was installing his own lithium system trip over one of the M8 cables on the lithium battery and rip the end off. These diagrams show the pinout on those cables if a repair is necessary.
This client came to us with an existing 400W solar charging system using flexible panels (which we discourage due to reliability issues) and an additional 120W folding panel. We replaced the original roof wiring because one of the four panels had stopped functioning, added two SP100 solar panels and upgraded the charge controller. We also replaced the PWM charge controller on the folding panel and added a Victron MPPT charge controller with Bluetooth monitoring. Next, we added a 600Ah Signature lithium battery bank and a 3000W inverter, which all fit tightly under the bed. This is one of our most elaborate installs.
Four months prior these clients had us install four SF160 solar panels and a SunRunner Signature 40/2 Pro Core. On this installation they swapped out the Blue Sky components for Victron, added another 640W and got one of our 800Ah Signature lithium systems. Now they have 1280W of solar with one of the most advanced RV battery systems on the market.
A client brought in his 2015 Airstream with the following request of AM Solar:
Design an off-the-grid power system (for dry camping and boon-docking) that “runs itself” and requires as little maintenance and oversight as possible both when the trailer is being used and when it is stored.
- Trailer is used for six weeks in the summer, often in shaded campgrounds, 95% of the time without electrical hookups. Stays range from 3-5 nights before moving to next location. Trailer is also used during the other three seasons typically for three-night stays.
- Client has monitored his power usage in the trailer for the last year and a half and concluded that 40-50amp hours is the typical 24 hour energy usage.
- Client doesn’t want to have to bring the batteries to a full charge after each use. Due to not utilizing campgrounds with electrical hook-ups, staying in shaded areas, and often driving short distances between destinations, there is often not enough time to fully recharge batteries via solar and vehicle alternator, especially in the off-season.
- When sun is available, the client wants to utilize every watt possible from their panels to recharge the batteries as they often only travel 2-4 hours before stopping at their next destination.
- Client wants an option to add additional battery capacity and/or solar panels if desired for future energy needs.
To accomplish the above client goals we spec’d one of our Lithium Battery Systems, solar panels, solar charger, and battery charger.
- Because the customer has light AC loads, we chose a 200Ah Essential Lithium Battery system. This will comfortably give them the five nights of camping desired with almost no solar panel input if they are camping under trees in the winter. If the client desires greater battery capacity in the future, this system can be expanded easily with an additional 200Ah bringing the total to 400Ah. Additionally, unlike lead-acid battery based systems, the lithium battery does not need to be recharged to 100% after each use.
- Due to the potential for tree cover, we chose 400W of solar panels to give the client ample solar charging capacity.
- We chose a 50A charger to maximize all available power (solar and vehicle alternator) to recharge the batteries as quickly as possible.
- We chose a three-stage battery charger so that the client can leave the trailer plugged in when stored without having to be concerned about the batteries being charged correctly.
Because the BMS on the Essential system acts on the negative side of the batteries (ground control), the negative (or chassis) from the tow vehicle with the alternator is at a slightly different voltage than the negative output of the lithium system. This creates a design challenge since shorting the negative output of the lithium system to the tow vehicle chassis would damage the BMS.
In a van conversion or coach, the issue of having two different negatives is easily resolved by routing the output of the lithium battery through the Orion 12/12 DC converter. The negative output of the Orion converter can then be tied to the chassis and all positives for the DC loads get re-routed to the positive output of the Orion. If the total DC load is more than 30A, multiple Orion converters can be connected in parallel. Inverters, or anything else that can have their negative isolated from the chassis will just connect directly to the output of the lithium battery system without going through the Orion converter.
In trailers, the issue of having two different negatives is solved differently. In this situation, the Orion converter goes on the input side of the lithium system, thus isolating the trailer from the tow vehicle’s chassis. When this is done, the Orion converter has to be modified so it’s output voltage is 14.2V instead of the factory 12.0V. This is accomplished by carefully tuning a potentiometer inside the converter that is accessible when the cooling fan is removed. This design will limit alternator charging current to 30A, but it will protect the BMS from having it’s input and output short circuited.
This coach came to us with a complex battery management system that had to be bypassed with a network of diodes in order for the lithium battery bank to function. It was a challenging install, but everything worked out in the end. The customer now has a 960W solar charger with a 300Ah lithium battery bank and a 3000VA inverter.
This customer came to us wanting the best of the best and the most that could reasonably fit in their rig. They ended up with a 960W solar charging system and a 600Ah battery bank with a 3000VA inverter. With a system like this they can enjoy all the comforts of home, while on the road.
We rarely recommend our Signature Lithium systems as a Do-It-Yourself project because of their complexity, but a few savvy customers with technical backgrounds have taken on the challenge. Tight and neat… Well done Steve.
This customer came to us wanting as much solar and lithium as we could fit in the rig. The result was 850W of solar panels, an 800Ah lithium battery bank and a 3000VA inverter.
We have never heard a customer say “I got too much solar,” and this customer will never be able to say “I should have gotten more solar,” because the roof is completely covered. In addition to the 830W solar charging system, a 600Ah lithium battery bank and a 3000VA hybrid inverter make this a very powerful vehicle.
This trailer came to us with an existing solar charging system and a conventional inverter. We rewired the AC circuitry to enable load sharing with a Victron 3000VA hybrid inverter. In other words, this system can now draw from shore power and the battery bank at the same time. We also upgraded the lead-acid battery bank to a 400Ah Signature Lithium system with Color Control Monitor showing complete system status. The result is a very powerful yet compact system.
This is the most sophisticated AM Solar installation ever. The 1920W solar array was producing over 90A when the system was first activated (in overcast weather). That high current, coming from dual 70A charge controllers, was fed onto a Victron 800Ah lithium battery bank where a 3000VA hybrid inverter would power all the comforts of home to this power plant on wheels.
We installed a 300W solar panel system with an MPPT charge controller and a 300Ah AMS Generation 1 Lithium Battery System. In order to install the battery bank and access the existing inverter we had to very carefully remove the bed and then put it back once everything was connected.
Space constraints were a major issue with this rig. We had to reinforce the bay and temporarily remove the bay door to get everything to fit. In the end we managed to install two Victron lithium 200Ah batteries in our Signature lithium system feature complete cold weather charging disconnect systems. The inverter is a Victron hybrid 3000VA and there is 1120W of solar panels on the roof.
When air conditioning is important, you better go big with your battery capacity. This customer got an 800Ah Victron Signature lithium system will full cold weather charging disconnects. The Victron 3000VA inverter/charger can draw from shore power or a generator at the same time as it draws from the battery bank to power large loads like air conditioners.
We installed 640W of solar using four 160W solar panels and a variety of “L” foot sizes to accommodate the curved roof. We also installed a 420Ah lithium battery system and a Magnum inverter.