Hi David, This upgrade comes up a lot. You are at a point where you have to decide; do I match my old equipment with a new 24V Lithium battery bank (thus limiting my battery bank options), or do I upgrade my equipment to 48V which opens up the brands available?
I have had good success matching older equipment with new batteries but my preference is always to try to get these systems to 48V if it's financially viable. Ray describes a solution to get the LBCO high enough to shut off the inverter before the BMS shuts down and this works. You can also hardwire a power supply to wake up the BMS directly from the generator. Remote monitoring is very useful too, especially in a rental scenario like this. It may be time for a full upgrade. Very hard to know which companies will make it through... On Tue, Sep 17, 2024 at 4:01 PM Jason Szumlanski via RE-wrenches < [email protected]> wrote: > I don’t want to stray too far off track, but it’s worth discussing how > challenging it is to predict which manufacturers will be around in a few > years. > > I know this might be a touchy subject, but Enphase is beginning to offer > full off-grid support. While I’m fully aware of the drawbacks of their > system architecture for off-grid setups, it’s also important to acknowledge > that no manufacturer is “too big to fail”—but Enphase is about as close as > we have right now. If something were to happen to them, the reliance on > remote access for the system functioning is concerning. It could > essentially become a big brick if a service issue arises and there’s no > support. On the other hand, Enphase may be a safe bet for certain off-grid > systems if you think they will come out on top. > > But the reason I bring Enphase up is modularity. Building systems with > interconnected components from various brands can spread the risk. Sol-Ark, > with its “battery agnostic” approach, is a reasonable choice, as long as > there’s a replacement all-in-one option if they were to go out of business. > EG4 and Midnite seem to offer alternatives in that space now. As long as > LiFePO manufacturers stick with 48V/51.2V standards, complete battery > replacements should be straightforward. However, I do think that large > battery sizes like 5 kWh (or even 13.5 and 14.3 kWh) could be problematic. > Personally, I prefer the concept of smaller, 1 kWh chunks. In the case of a > 40 kWh battery bank, for example, if one module fails and the manufacturer > is no longer around, it’s a lot easier to deal with. That's similar to how > we can drop one faulty 2V cell in a series of 24 lead acid batteries > sometimes. Enphase, if you think about it, is the least modular approach in > some ways, since it relies on a single manufacturer with a proprietary > system. So the whole concept of modularity is not straightforward, either. > It's a fantasy at this point to hope for a truly modular and > manufacturer-agnostic system. > > What I find interesting is that most of my clients who went off-grid 7-15 > years ago are pretty understanding when I tell them it’s time to replace > their systems. Realistically, fast-forward another decade, and we’ll > probably see significant advances that make a complete system replacement > worth it once again. I’m not saying we should be designing disposable > systems, but that might be where we’re headed, just like so many other > industries. Think of what Tesla is doing with the Powewall 3. They are > making solar and batteries as cheap as possible (while maintaining high > quality standards and keeping fuel in Elon's jet). However, when the PW4 > comes out, the PW3 will be deprecated, and those systems will become > essentially disposable. The warranty is only 10 years. So when the inverter > insude the PW3 dies in year 11, guess what – the entire PW3, battery and > all, may be rendered useless. But, people still flock to Tesla for backup > systems. And for good reasons. > > The days of keeping systems running on old components while upgrading just > parts of the system are probably behind us. The rapid evolution of > technology, equipment, codes, safety, and consumer needs will make whatever > we install today obsolete soon after it's up and running. > > > --end rant-- > > Jason Szumlanski > Principal Solar Designer | Florida Solar Design Group > NABCEP Certified Solar Professional (PVIP) > Florida State Certified Solar Contractor CVC56956 > Florida Certified Electrical Contractor EC13013208 > > > On Tue, Sep 17, 2024 at 5:20 PM Ray Walters via RE-wrenches < > [email protected]> wrote: > >> Honestly, that advice would seem to be true, but the reality is: It is >> not valid. Just look at Blue Planet, that was supposed to be a top tier >> offering. Solar World? AEE? Magnum has had serious issues, Outback >> doesn't answer the phone, SImpliphi takes an attorney to honor their >> warranty. Even long standing companies are not sure bets, at all. They >> do cost much more, so I'm not sure who to turn to anymore. I'm about to >> install Rubix LiPO4, which comes in a 24 v offering, BTW for Dave. >> >> The biggest issue I've seen with old VFX inverters, is the LVD set point >> can't go high enough for LiPO4. I use the aux out on a charge >> controller, to switch on and off the remote switch on the VFX. >> >> I like the Fortress with Solark combo, but its not without its troubles >> either. If the Solark shuts off due to low voltage, so does your PV >> input. Then the no load draw on the Fortress eventually shuts down the >> battery. You really need some (at least 1 kW) of DC coupled PV to keep >> that death spiral from happening. >> >> Ray Walters >> Remote Solar >> >> On 9/17/2024 12:23 PM, Sindelar Solar via RE-wrenches wrote: >> > Jerry, >> > Re your advice to never get startups or small manufacturers as so many >> > disappear and now you are stuck, I guess we should stick with the big >> > well-established manufacturers, like Outback, Magnum and Blue Planet, >> > right? >> > As you would say, fun times... >> > Allan >> > >> > On 9/17/2024 10:58 AM, Jerry Shafer via RE-wrenches wrote: >> >> Dave, >> >> I would suggest stepping up to 48 nominal, fortress 18.5, battery 12 >> >> or 15 k solark inverter, re-wire the array to single or dual string, >> >> make the wiring in the home capable of 240, this usually requires >> >> main panel re-work and set up the monitoring. >> >> Batteries are like replacement heart valves, never get startups or >> >> small manufacturers as so many disappear and now you are stuck. >> >> Fun times. >> > >> > _______________________________________________ >> > List sponsored by Redwood Alliance >> > >> > Pay optional member dues here: http://re-wrenches.org >> > >> > List Address: [email protected] >> > >> > Change listserver email address & settings: >> > http://lists.re-wrenches.org/options.cgi/re-wrenches-re-wrenches.org >> > >> > There are two list archives for searching. When one doesn't work, try >> > the other: >> > https://www.mail-archive.com/[email protected]/ >> > http://lists.re-wrenches.org/pipermail/re-wrenches-re-wrenches.org >> > >> > List rules & etiquette: >> > http://www.re-wrenches.org/etiquette.htm >> > >> > Check out or update participant bios: >> > http://www.members.re-wrenches.org >> > >> _______________________________________________ >> List sponsored by Redwood Alliance >> >> Pay optional member dues here: http://re-wrenches.org >> >> List Address: [email protected] >> >> Change listserver email address & settings: >> http://lists.re-wrenches.org/options.cgi/re-wrenches-re-wrenches.org >> >> There are two list archives for searching. When one doesn't work, try the >> other: >> https://www.mail-archive.com/[email protected]/ >> http://lists.re-wrenches.org/pipermail/re-wrenches-re-wrenches.org >> >> List rules & etiquette: >> http://www.re-wrenches.org/etiquette.htm >> >> Check out or update participant bios: >> http://www.members.re-wrenches.org >> >> _______________________________________________ > List sponsored by Redwood Alliance > > Pay optional member dues here: http://re-wrenches.org > > List Address: [email protected] > > Change listserver email address & settings: > http://lists.re-wrenches.org/options.cgi/re-wrenches-re-wrenches.org > > There are two list archives for searching. 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