Starr's Lithium Power Story
Lithium power options and pricing in general, and at SMB-West in particular, changed a lot during the 2 years that Starr was in development. Lithium's advantages over AGM (i.e., weight savings, depth of discharge/DOD, increased life/recharge cycles, and speed of recharging) were attractive; increased environmental constraints and highish price were not so much. During this time, long-established AGM technology/products appeared stable and unchanging (announcement of Carbon Foam AGMs is only very recent news). One huge change was that the RVIA removed the requirement that Lithium enclosures be vented.
SMB-W's Lithium offerings changed from a ala cart menu of 2-3 ever-changing battery choices to a single "No Brand" solution, where they were free to focus on designing a single configuration of pieces that "just works." It was reported on this forum that they had built a few Lithium powered vans, but apparently none in my popular RB150S floor plan. Last fall when I had to commit to a final design, I took a deep breath and took the leap with Lithium. When I was then given the final Production Order floorplan to approve, I noticed that the Lithium battery's enclosure box took up a full half of the rear under-bed storage area! Not only is this a huge loss of the obvious storage space, but precluded me from the planned installation of the Van Compass under-floor storage box. Not good! So, I STRONGLY pushed back on making the enclosure smaller, but I only got "that's the way it has to be" (one guess at the time: their single Lithium solution was designed for both 1 & 2 batteries). So, then I pushed to have the battery installed anywhere else so as to not loose all that storage space. I was lobbying to put it under the driver-side closets, losing as much of that less-valuable-to-me lower storage area as necessary. Still, no-go on anything other than SMB-W's proposed solution. And all this is happening at the eleventh hour -- my van was supposed to be starting production, at the front of the just-arrived 50+ van wave. I feared that every day's delay in the van design's signoff and production start, was allowing other vans to slip in front of Starr. So, when I learned that SMB-West could custom install one of their under-floor boxes off-center in the remaining under-bed area, I sucked-it-up & signed off on that design.
So, fast forward to this March and we're in Fresno to pick up Starr... lo & behold, the Lithium battery enclosure is half the size of what was shown on the Production Order! And the under-floor storage box is in its typical centered position. Hallelujah! And their "No Brand" battery solution was:
- Battery -- Relion RB-300 (one of my top two choices!)
- PV Panels -- two Zamp 115W (yay!)
- Solar Charge Controller -- Blue Sky SB3000i (OK choice; I would have preferred a Zamp)
- Battery Monitor -- BM Pro bluetooth wireless (see below)
The BM Pro was a disappointment -- it only displays SOC as a simple percentage on its smart phone app, which bluetooth-connects to the monitor hardware mounted on the battery. The app continually pops to the forefront of your phone's display as it gains and loses connection -- VERY annoying. Furthermore, I noticed that its displayed SOC % was never less than 100%. Digging deeper, I learned that it was not Lithium compatible -- it was programmed only for AGM's relatively steep voltage SOC slope. So I returned it to SMB-W and thankfully no evidence was left behind (e.g., a cabinetry hole). I installed a Relion Battery Monitor, which I love. [see attachment for picture] It measures the voltage drop across a shunt installed on a battery's neg terminal, and therefore it can measure the actual instantaneous current in or out of the battery. And, after setting it up with your battery's capacity (300AH), it keeps a running total of AH out & in, so you get a very accurate SOC (in % or AH). But you can also display that instantaneously-measured +/- current. So you can easily see:
- Device draws (e.g., idle inverter, induction cooktop at various heat levels, etc.) AND
- Charging currents (e.g., solar at various times/seasons, 2nd alternator at various idle speeds, & shore-power; no need for a clamp-on ammeter)
And all this is continuously displayed for all to easily see, whenever (rather than having to pull out a phone).
Now, regarding battery capacity... 300AH was at the bottom limit of my desired total battery capacity, but interior van space is more important to me than another 100-300AH. And if 300AH proves insufficient once in awhile, Starr has the 170A 2nd alternator and high-speed idle option (alternator puts out 90A when battery is 90% SOC; more measurements to come). We have not taken Starr on an extended outing yet, so ...
One regret -- I wish that I had the originally planned Van Compass under-floor storage box. I had planned to store a receiver-mount winch there, and the smaller SMB-W box severely constrains my winch choices.