You Sprinter and B Van forum long-timers (what very few remain here) will recall that my husband and I were early adopters of lithium tech. The thread “
My Interstate lithium battery adventures”, which my husband LB_3 started in mid-2016, explains a big part of our journey.
Fast forward 8 years and we are all a whole lot wiser about lithium, and none too happy about what we have learned. Our original DIY-built system has now lost 40% of its capacity despite having very few cycles on the battery, and despite being well-cared-for.
Not only that, we have known for some time that our lithium cells were in a death spiral. They really only lasted about 6 years before they became unworkable. We cannot off-grid on just 60% of our original design capacity. They were sized correctly to begin with and that’s what we need to restore now. The failure of the original cells is financially painful, but that’s the risk that comes with any early tech adoption.
There were previous indications that the original advertised lithium iron phosphate performance was not going to survive first contact with the enemy, which is experience. Research Technomadia’s chain of historical lithium posts (they were one of the very first adopters) and you will see what I mean. They, too, were confronted with a similar rude shock about battery life. It’s not just us.
*WHY* did this happen?! It happened because the battery manufacturers led us all to believe that the big booger for lithium’s lifespan was total cycles. Now we know that, for non-full-time users like ourselves, LiFePO4 is going to age out far more quickly than it cycles out.
Furthermore, we suspect that our severe subtropical temperatures (Houston, TX) helped to hasten our cells’ demise - lithium does not like scorching hot weather. For that reason, we vowed that our next lithium purchase will be modular, such that we are able to remove it from our van during the hottest months of our year when we suspect the most cell damage is inflicted.
With that removal criterion non-negotiable, and with Cyber Monday in mind, we plan to attempt a Yeti Pro 4000 retrofit. We think it will be possible with attainable cabinetry modifications. As I noted to several others of you on another recent thread, IMO this is the future of all RVing - modular systems adequately sized, off-the-shelf plug-and-play, and we just wheel them into our vehicle when preparing for a trip. Wheel them back into the air conditioned space of our homes when environmental conditions are less suitable for them.
Removing the modular heart of our electrical system will really not be that cumbersome. I anticipate we will be shuttling it in and out of the van maybe 4 times per year. We can leave it
in situ during the entirety of the cool seasons, then remove it for whatever portions of June, July, August, and September do NOT have us traveling north (which we try to do every year in August). Then when the cool fronts start rolling through again in October, reinstall the unit for the winter, which is our active season.
Our only other practical option was to leave the remainder of our electrical guts in place and just replace our original lithium cells with new ones in kind. But that replacement alone would have cost about $900, and it would not have been responsive to our summer heat problem. Furthermore, our inverter is now also 8 years old and it can be glitchy, so I would rather not invest in new cells only to have to replace the danged inverter a year or two from now - it doesn’t seem cost-effective.
Hence, the plunge, the biting of the bullet. We THINK we can do this retrofit, but we haven’t done it yet, so stay tuned for what will no doubt be a series of lessons learned.
Screenshot of the unit in case the links change in the future:
Linear Mode
