Hi There – A couple of weeks ago I reported that I had switched out the factory NAPA 8231 lead acid batteries from our 2021 View for a couple of Battle Born 100 AH lithium batteries, and had no installation issues. After re-programming the Zamp solar controller, and the Xantrex inverter / charger, the system is behaving well. Except for having to pick up a couple of longer paralleling cables to fit the different geometry of the Battle Born terminal posts, all was pretty straightforward.
Recently I added a Victron BMV 712 battery monitoring system, and an ISL Products Amp – L – Start chassis battery maintainer. Those mods went smoothly as well.
The
BMV 712 is a great addition to the LiFePO4 batteries setup. Prior to installing it, I’d look at the battery voltage on the OnePlace panel ... and just kind of shrug. We have only used our new View for three relatively local trips since receiving it in mid September, but just as everyone reports, it certainly was difficult to get an idea of where the lithium batteries really were sitting due to its relatively flat discharge curve. With the BMV 712, there is no shortage of data to look at, and of course, the state of charge reading takes all guesswork out of wondering where the batteries are sitting. Was the extra money for the 712 worth it? Well, I’d have to say it was. Standing in the garage, activating the Bluetooth app to configure the system, the first thing it did was download updates for both the software in the shunt, and firmware in the gauge. After that, programming the system was straightforward. I used the recommendations from AM Solar in Oregon to optimize the setting for the Battle Borns. Here is a link to their recommendations:
https://amsolar.com/rv-solar/support
Using the app was straightforward, and they even have a demo mode that you can use to get familiar with what you need to do prior to getting at the install for real. I’m not sure how you would get updates if you bought the 702 or 700, but I’m guessing it would not be as straightforward as the 712. I’m not really a cell phone guy, but until I get the gauge mounted (next spring , I guess), reading this app is pretty slick.
Probably the most difficult thing I was faced with was the decision as where to mount the shunt sensor. I ended up choosing the wall of the battery box step well that faces the door, as most people do. The couple of bolt heads showing up beside the step well latch don’t really look all that bad...
The
Amp – L – Start installation went fine as well. Prior to the 2020 year, the recommended location from everyone who has installed its brother, a Trik – L – Start, in a View was to install the connections to the posts of the battery relay solenoid under the passenger’s seat; easy to find, easy to do. On the 2020 / 2021 Views they eliminated that solenoid and replaced it with a current limited electronic charge relay, still located under the passenger’s seat. This relay does most of the same job as the old solenoid, but its extra addition to the motor home was to control the charge current from the Sprinter's alternator, limiting it to 40 amps. Now that they have a LiFePO4 option out of the factory, and knowing that customers were going to drop in their own lithium batteries, I was told by Forest City that Mercedes asked Winnebago to install a current limiter to protect the chassis alternator from the aggressive charging that lithium batteries are capable of demanding.
I had been not looking forward to removing the passenger seat, for some reason. I imagined having to deal with motors and wiring, awkward disconnects of cable plugs that I always seem to have trouble getting apart, and then getting something wrong when putting it all back together. My imagination took me as far as having to admit defeat while booking an appointment at the dealer I usually dread going to. But, it turns out there is an RV mod god after all. Four torx bolts, and the whole seat assembly lifted off without having to disconnect the lone electrical cable. The cable has enough slack that you can support the seat gently on the driver’s seat, and you have full access to the gear under the seat pedestal. Ok, I had to go out and buy a torx socket set... but I have always wanted one of those anyway...
The MasterVolt charge relay is mounted on the aft wall of the pedestal box, and right above it is a shelf that is perfect for the Amp – L – Start to sit. I mounted the Amp – L – Start as close to the outboard wall of the pedestal as comfortable, so when the seat is back installed you can lift the Styrofoam cover sheet underneath and have a look at what the unit is doing.
Why an
Amp – L – Start and not a Trick – L – Start? ISL Products recommend the Amp – L – Start if you have lithium coach batteries, because the turn on/off thresholds are optimized for the lithium batteries elevated, flat, discharge curve. I you used a Trick – L – Start with Lithium batteries, you would end up providing the maintenance charge to the chassis battery continuously if you had shore power, solar, or alternator charging available. The typical turn off voltage associated with lead acid coach batteries would never be seen in these conditions. If you were dry camping, the Trik – L - Start would keep maintaining the chassis battery until you were below 20% state of charge on the coach batteries, thereby contributing to the coach batteries discharge – exactly what you don’t want either. With the Amp – L – Start, the turn on/off voltages are very near the top of the lithium batteries SOC curve, so it truly will only maintain the chassis battery when the coach batteries are really being charged.
Does it work? Well, yes it does. So far so good. I’ve watched the sun come up and wake up the solar controller, seen the solar controller decide it wants to give a shot to the coach batteries, watched as the Amp – L – Start flips over to a charge cycle to give the chassis battery a spurt of charge current, and then have seen it all shut down as the solar controller decides the coach batteries are good enough - followed by the Amp – L – Start losing interest in maintaining the chassis batteries. I don’t have much time left before I have to shut down the RV operation for the season, but I’ll let you know in the spring if I find something contrary to all of this. If someone else out there has some experience with an Amp – L – Start and lithium batteries, please let us know.
That’s it for now, hope that helps those that are thinking of the same mods.
Everyone keep safe out there.
Cheers,
Linear Mode
