24v Bank Dead - upgrade to 24v LiFe or scrap system for 48v - WANTED recommendations

[Zwy]

Yes but you have to understand that I designed & built my home and did so with Efficiency in mind because right from the start (even before buying my land) I knew I was going offgrid solar powered with this build... It's my final build and my Bucket List item I wanted to do and I had a lot of time to plan & implement it.

• 1 bedroom, Full Bath, 2nd story loft, 9/12 pitch roof (Cathedral Ceilings)
• FPSF Slab Foundation R-20 HD-Foam Insulation under it & up the sides.
• Radiant Heating in floor with 7/8" Pex
• Cool Roof System (saved 25-30% of Heating & Cooling costs and is incredible ! (Thermally Broken Roof)
• Rain Screen Siding method (used Live Edge White Cedar as my finish) (Thermally Broken Walls)
• INSULATION: (All obtained from Commercial Roofers - not available in retail land)
• -- 4" XPS Under the FPSF Slab and out the sides (wings) 24" providing R20, double code requirement.
• -- 5.25" High Density EPS-2 Foam between 2x6 studs R32)
• -- 7,5" Paper Faced PolyISO between Rafters (Cathedral Ceiling, roof is 9/12 Pitch)

There is a lot more info but it does not belong in this thread. Bottom Line, is that a well-built efficient home that uses Passive Technologies to maintain its livability is far cheaper than Generation & Storage and has an immediate payback in comfort & affordable livability. The passive airflow between the RainScreen Siding & venting through the cool roof via natural convective forces os not new and is extremely effective.

Fact is, my Heating System runs for 4 hours per day to keep 25C/77F Temp in house even when it is -30C/-22F. Additionally, during summer the Radiant Slab is a Thermal Regulator which never goes over 19C/62F and therefore keeps the home cool which the Thermally Broken structure which prevents heat transfer into the house from outside.

You missed it Steve. Go back and read my post again. And read what I quoted.

 

[Brucey]

Yes the waiting is hardest part!

Are ecoworthy decent quality?
Batteries look suspiciously similar to LiTime. I wonder if they are made in the same factory.
If the quality is decent, their solar trickle charger looks like a great deal and would be perfect for my boat.

I have two of their 24V 100Ah "minis" in addition to the djlbs, work fine in series, and one of their 48V 50Ah as well.

 

[robbertwilliams]

Thanks for all your help thus far - I ordered two of the Eg4 LL V2 24v 200ah. I like the “don’t fix it if it ain’t broke” - so sticking with 24v. Ordered from Solar Sovereign - free shipping this month. I went with eg4 specifically because they have low temp charging shutoff - I guess I’ve got a battery temp sensor already on the midnite classic and also in the inverter but it sold me and the fire arrestors (a little peace of mind for me having no experience with electric cars, e-bikes, hoover boards and their failures…news does actually get to South Dakota - so, if they work great; if they’re not needed…makes me sleep a bit better at night)

 

[seneysolar]

Thanks for all your help thus far - I ordered two of the Eg4 LL V2 24v 200ah. I like the “don’t fix it if it ain’t broke” - so sticking with 24v. Ordered from Solar Sovereign - free shipping this month. I went with eg4 specifically because they have low temp charging shutoff - I guess I’ve got a battery temp sensor already on the midnite classic and also in the inverter but it sold me and the fire arrestors (a little peace of mind for me having no experience with electric cars, e-bikes, hoover boards and their failures…news does actually get to South Dakota - so, if they work great; if they’re not needed…makes me sleep a bit better at night)

Fyi the battery temp sensor on the Midnite will not be used on LFP batteries. Its for raising or lowering the voltage based on temp for lead acid chemistry batteries.

 

[robbertwilliams]

Fyi the battery temp sensor on the Midnite will not be used on LFP batteries. Its for raising or lowering the voltage based on temp for lead acid chemistry batteries.

Thanks. I’m kind of excited for this…wasn’t too excited about the purchase. But I’ve been trying to get rid of unnecessary life maintenance activities (LMA’s) - and watering batteries has not been a favorite. Been off-grid for almost 10 years and has felt good but my god…it seems you’re always working on something - might as well be living on a sailboat - our next move.

 

[Rednecktek]

Fyi the battery temp sensor on the Midnite will not be used on LFP batteries. Its for raising or lowering the voltage based on temp for lead acid chemistry batteries.

Just out of morbid curiosiry, if you enabled it as FLA and turned on temperature compensatiin, would that save a LFP when it gets down around freezing?

 

[HRTKD]

Just out of morbid curiosiry, if you enabled it as FLA and turned on temperature compensatiin, would that save a LFP when it gets down around freezing?

No. The LiFePO4 battery should be charged with fewer amps the closer the temperature gets to 32°F. FLA temperature compensation increases the voltage the colder it gets. It's amps versus volts, but you don't want to use temperature compensation with a LiFePO4.

 

[pollenface]

No. The LiFePO4 battery should be charged with fewer amps the closer the temperature gets to 32°F. FLA temperature compensation increases the voltage the colder it gets. It's amps versus volts, but you don't want to use temperature compensation with a LiFePO4.

Do you know if there's a formula for current reduction based on ambient temps for LFP? Just curious. Have recently learned that my LFP powered EV should not be fast-DC charged when the battery is below 25°c

 

[Brucey]

Do you know if there's a formula for current reduction based on ambient temps for LFP? Just curious. Have recently learned that my LFP powered EV should not be fast-DC charged when the battery is below 25°c

Which EV is it? Most nowadays have some type of liquid coolant maintaining battery temps in the proper range and can charge well below freezing.

Now if this is a vehicle that's you've converted to electric/battery then yes you should take precautions when charging at high rates.

 

[HRTKD]

Do you know if there's a formula for current reduction based on ambient temps for LFP? Just curious. Have recently learned that my LFP powered EV should not be fast-DC charged when the battery is below 25°c

I haven't seen a formula, but there's probably one out there. In one of the threads that discusses why you don't charge LiFePO4 below 32°F there was a graph posted that showed decreasing amps the closer the temperature got down to 32°F. As I recall, it was a curve, not a straight line. But it's been a couple years since I saw it.

 

[Steve_S]

24V with Midnite SCC's here.... Check out this thread, you'll likely find it useful.

Steve_S-Tech: My Final Config for Midnite Classic SCC & JKBMS' w/ Large Bank (works amazingly well) Includes Charge Profile & BMS Config

INTRO: I have debated posting this for a while until I got everything tweaked in and working as best as possible. The End Result is Gobsmackingly Good ! I cannot speak for other SCC and such as each is different & unique in their own ways BUT this may likely be a Good Reference. Civility &...

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