IIRC, I never could find exactly what the "Lithium setting" on the REDARC meant exactly in terms of charging profile. But, if you are seeing the charge rate drop to zero when the battery gets to 14.x volts, that's a good sign. The next good sign would be to watch the battery voltage after it stops charging (with little or no loads). It should settle down to between about 13.3 and 13.4v (in other words, the resting voltage of a full pack). This would mean that if there is a float charge, it's at a low enough voltage to not be doing any damage. If the battery voltage sits higher than that after bulk charging stops, probably means there is some float charging going on. Yes, I think the jury is out on weather float charging at, say 13.6v is bad or not. Definitely bad to float in the mid 14 volt range. That is what will start to eat away at your capacity. Either way, this battery chemistry just does not need float charging so it's best to have a system that just doesn't do it.
I wouldn't worry about doing full charge and discharge, my understanding is that Lithiums are very happy to rarely if ever go in the tail ends of their capacity.
Hadn't heard of Revolution Power. First firm I've seen selling self-contained lithium to admit that you do in fact need a different charge profile than lead acid. So, kudos to them!
Yeah, in San Diego now - actually just moved here about 8 months ago from CO, where I had been working as a Victron systems consultant and Bay Marine Supply hired me here as their tech support guy. We're near-ish the arena, at Fairmount Ave and Mission Gorge... but be advised we're not a retail location, no showroom, we're literally three desks, a test bench, and a big warehouse.This is a great, well written, informative reply! THANK YOU @Justin Cook
I see you are in San Diego... still? I am as well..
About to start a huge project and would be great to support someone local (and to pick their brain in person)..
Are you at the Bay Marine Supply over there near sports arena?
With all due respect, this is a myth.Full stop. Storing a lithium battery at high SOC causes capacity loss. It is a function of the chemistry.
...I could go on, but the point is that the myth of an LFP cell losing capacity when stored at 100% SOC isn't supported by a current understanding of how the chemistry works and performs over the long term.
Yeah, in San Diego now - actually just moved here about 8 months ago from CO, where I had been working as a Victron systems consultant and Bay Marine Supply hired me here as their tech support guy. We're near-ish the arena, at Fairmount Ave and Mission Gorge... but be advised we're not a retail location, no showroom, we're literally three desks, a test bench, and a big warehouse.
Picking my brain in person is expensive, I have to warn you - we're by appointment only and time in person is billable, but I'm free out here on the various forums, or shoot me an email at justin@baymarinesupply.com and I can offer advice, component recommendations, and/or put together a system quote for you. We don't do installation or -with some exceptions- design work (though I have developed a fair number of component interaction reference schematics), but if you have a schematic that you need to have looked over we do offer that as a service, and there is a very short list (literally 2 guys) of installers in the area whose work we've seen and trust and feel comfortable recommending to people, so if you need help in developing a comprehensive schematic and/or help with the actual installation, these guys are great and I'm happy to share their contact info - just drop me an email.
Our big thing is technical support, really... you can get Victron components a whole lot of different places, but since all Victron technical support and warranty matters are handled by the dealers and distributors rather than by Victron, it's important to know that your dealer has expert technical support on staff. Our pricing, like everyone's, is based on Victron's set MAP (although we can usually do some degree of package pricing when we get into a full system), but we're the largest stocking distributor in the western US and the most technical distributor in the entirety of the US, so that's how we set ourselves apart from the other dealers/distributors.
Drop me a line anytime, I'm happy to answer questions/make suggestions!
Haha fair enough... agree to disagree on this one (though, one note: two of the manuals I quoted say store at 100%, two say at 50% - just for the record). I see that marine how-to article quoted a fair bit without regard to exactly how dated those articles are... but I'll leave the argument off here Cheers!The quoted manuals directly contradict your statement though. They specifically state to discharge before storage. If sitting full doesn't harm the pack, then why do that? I am not saying its catastrophic, but if you are looking to get 10 years from a pack, the extra 1-4% per year makes a difference. If a drop-in pack has a poorly designed BMS, its possible for the BMS to drain the pack beyond the safe threshold, and cause anode breakdown and voltage reversal. That is likely why many drop in makers suggest staying above 50% SOC. The research indicates that the degradation rate is pretty constant between 40-70% SOC, significant reduction occurs below 40% SOC, so anywhere between 40-70% going to have similar results. Now obviously cell/electrolyte designs have been improving, so the degradation rate may be lower with newer packs, but I have not seen any testing to show a huge change in the last few years.
Sitting at low SOC causes no harm to the pack (unlike lead). The only time damage would occur is if the cells are taken past zero SOC into the voltage reversal and breakdown territory. Anything above this is fine. Technically there is a bit more cycle loss when using the last 5% or so, of the packs capacity, but since most drop-ins have no issue using it, I don't think its worth worrying about.
Those drop in MFGs have various reasons for their choices in those cases. I don't have time to post the relevant studies, but detailed work has been done showing the degradation of the anode and electrolyte from extended storage at high SOC. This is why almost every cell maker that supplies raw cells to MFGs provides them at partial SOC. Lots of great reading over here. https://marinehowto.com/lifepo4-batteries-on-boats/
The data shows that the lower the SOC, the slower the degradation. This is by neutral third parties testing cells. Even storing at nearly zero SOC is okay, as long as the BMS completely shuts down (not all do). If there is a true zero drain, storing at 10% SOC in mild temps is acceptable for as much as 2 years, before light top off back to 10% is suggested.
Anyways, I don't wan't to start a flame ware in this thread. If you would like to come over to the 12v/power subforum there is some great materials scattered about.
Yeah, in San Diego now - actually just moved here about 8 months ago from CO, where I had been working as a Victron systems consultant and Bay Marine Supply hired me here as their tech support guy. We're near-ish the arena, at Fairmount Ave and Mission Gorge... but be advised we're not a retail location, no showroom, we're literally three desks, a test bench, and a big warehouse.
Picking my brain in person is expensive, I have to warn you - we're by appointment only and time in person is billable, but I'm free out here on the various forums, or shoot me an email at justin@baymarinesupply.com and I can offer advice, component recommendations, and/or put together a system quote for you. We don't do installation or -with some exceptions- design work (though I have developed a fair number of component interaction reference schematics), but if you have a schematic that you need to have looked over we do offer that as a service, and there is a very short list (literally 2 guys) of installers in the area whose work we've seen and trust and feel comfortable recommending to people, so if you need help in developing a comprehensive schematic and/or help with the actual installation, these guys are great and I'm happy to share their contact info - just drop me an email.
Our big thing is technical support, really... you can get Victron components a whole lot of different places, but since all Victron technical support and warranty matters are handled by the dealers and distributors rather than by Victron, it's important to know that your dealer has expert technical support on staff. Our pricing, like everyone's, is based on Victron's set MAP (although we can usually do some degree of package pricing when we get into a full system), but we're the largest stocking distributor in the western US and the most technical distributor in the entirety of the US, so that's how we set ourselves apart from the other dealers/distributors.
Drop me a line anytime, I'm happy to answer questions/make suggestions!
Yeah man, definitely do! Our location is (deliberately) the single one you can't see in Street View because it's hidden behind a row of concrete columns We do have a very small display system that has a MultiPlus 3kVA and a CCGX and a SmartSolar MPPT 100/30 and a few switches and various components, so you're welcome to set up an appt to come by and have a look but yeah there's not much to look at... we're the largest stocking Victron distributor in the western US and the largest stocking Sterling distributor in the entire US, not to mention all the Blue Sea and Bussman and FTZ and Ancor and... on and on and on... so for better or worse all our available space is devoted to our warehouse for stock and a small corner for my test bench so I can learn how everything works and provide support for it to our customers. Our website has most of the stuff we carry listed on it (but not all) and it kinda sucks (we're working on a new one) but it's a good place to check things out and you can always call or email with any questions when you're getting close!Hi @Justin Cook That's a lot of good info. I actually looked up your address on Google maps and looked at the street view and didn't see a storefront showroom. I was bummed as I love to be able to see what I am buying in person, when it is local to me (I am in San Diego). I am in the early stages of planning and good to know you guys have a lot of the high quality build items I will likely need. Will definitely reach out when ready.