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Similar storage compartment in the front of my RV. I put down 1” foil backed styrofoam, then 1/4” aluminum plate with a 200w 48v heater sandwiched in between. 3D printed cell holders (that came with my packs purchased from Lion energy on fleabay) allow for some airgap between cells. Another...

Hardi-backer, cement-like board used behind tile work, available at most hardware stores.

Throw a thick blanket or reflective tarp over the PV panels in order to reduce their output voltage to a touch safe level.

Radio controlled aircraft, home automation, avid homebrew consumer!

Put a bigger dent in your bank account! LOL

Imagine how boring the world would be if we all thought alike! LOL

Your request reminds me of an old racing adage: cheap, fast, reliable - pick any two.

If any panels may be suceptible to shading, then parallel is best. Otherwise series as many panels as your scc will allow.

I haven’t, I’m just not a fan of having a potential single point of failure. OP asked for downsides of a single pack, just giving him one.

For me, it's not a single setting or single special feature, but a combination of features: 48V/16S compatibility and hardwired serial comms selectable top/bottom/both balancing Jason is actively engaged in continuous product development, and listens to customer requests The chargery is the...

Your understanding is more than you are giving yourself credit for. The key point is charging vs. discharging in subfreezing temperatures. I believe it’s perfectly ok to discharge LFP when cold, but charging is detrimental. Passive balancers discharge the cell with the highest voltage. Perfectly...

I have 64 of the same or similar cells, 50Ah, currently in 4P16S config in the front storage locker of my toy hauler. The pack rests on 1” styrofoam for both insulation and shock absorption. I live on a washboard road, so the pack sees its fair share of vibration. No issues so far, but it’s been...

I have my BSEE with 27 years experience in power distribution. The voltage dip on “start” and spike on “release” is characteristic of an inductive load. An inductor is basically just a coil of wire, which generates a magnetic field when current passes through it. When voltage is initially...

I'd like to see all cell manufacturers offer this type of terminal:

...and not necessarily in that order!

Spoken like a true Engineer! LOL My parents knew I was destined to be an Engineer when the first thing I would do with a new toy is take it apart!

If the pack has a BMS, a mid-pack open circuit will most likely damage/destroy the BMS.

Series connected panels are the way to go as long as your controller can handle the higher voltages (which it sounds like it can). There are several threads discussing the advantages of series vs. parallel.

Please elaborate on this statement. Show me an equally priced bms with similar features that comes in an anodized aluminum case. For us DIYers with remote monitoring needs beyond the range of BlueTooth, it's the only BMS in its price range with an auxiliary serial port. There's several of us...

I did something similar with a DIY 3-phase wind turbine which had 24 coils per phase. On startup, all 24 coils were in series. As RPMs increased coil arrangement transitioned to parallel in order to increase load on the turbine. Options were 24s1p, 12s2p, 8s3p, 6s4p, 4s6p, 3s8p, 2s12p and...

My best guess would be “arc blast”. Vaporized copper expands by a factor of 67,000 in volume, which is enough force to launch dang near anything!

I used this buck converter in my RV to eliminate the house battery. Now all 12v accessories are powered from the 48v bank.

I would guess the smaller gauge black and blue wires are from the BMS, likely mounted to the side of the battery (out of shot).

10AWG MC4 connections to a combiner box, then 8AWG from combiner box to SCC.

I finally got around to sniffing the data stream with a saleae, and saw no framing errors: Time [s],Value,Parity Error,Framing Error 0.244132960000000,$ (0x24),, 0.244219840000000,$ (0x24),, 0.244306720000000,W (0x57),, 0.244393440000000,'15' (0x0F),, 0.244480320000000,'16' (0x10)...

After seeing what you were able to accomplish on the main board, I’m confident you will find a way to make it fit! :LOL:

Comparing circular mils (cross sectional surface area) is probably a better comparison. 14awg is 4.107MCM and 1/0 is 105.531MCM, so it would take 26 14awg cables to equal one 1/0 cable.

Serial LCDs only require clock and data lines, one less than shift registers to drive LEDs. With appropriate pin selections (A4,5), both options could be made available in the design.

Griz, I placed the charge relay on the PV side of the SCC, so charging is interrupted without disconnecting the SCC from the batt bank.

An automotive test probe (old incandescent style) works great, or any automotive lamp (turn signal, brake/tail, etc) will work too. Super cheap!

Take a look at the Chargery BMS16T with a 600A shunt.

T Taps are not known for good conductivity or good current carrying capacity, so I would not use them for paralleling panels (or any application for that matter, but that's just personal preference).

My concern would be the machine screw termination at 200A continuous.

It’s not a good idea to series batteries with different capacities. During discharge, the 100Ah battery will reach 50% dod long before the 200Ah battery, likely resulting in reduced lifespan.

Your guess is correct. The current exceeds the ampacity rating of the switches, which will likely overheat and fail.

Assuming an 8SxP wiring configuration, Pros of smaller cells: Redundant strings. If one cell gives up, you're not dead in the water (bad pun) Cons of smaller cells: Dedicated BMS per string of cells. 500ah cells would require 4 BMS for a 2000ah pack, while 200ah cells would require 10 BMS...

Not much different than having exposed busbars, so my vote is the advantages outweigh the risk.

Yes, definitely feasible. I use a rc hobby charger to top off or discharge individual cells that are way out of balance. One word of caution when using multiple chargers simultaneously: Cheaper chargers may have inadequate isolation between their input voltage source and their output.

Looks a lot like my AIMS...

What shift registers are you planning to use for the LEDs and balancers? I’m sketching up an active balancer, and want to ensure full compatibility.

https://diysolarforum.com/threads/off-grid-solar-battery-monitoring-and-control-freeware.6662/

The Daly should measure ALL current in & out of the battery, and should therefore be the only thing connected to B-. All other equipment should be connected to P-.

An argument could be made there is some inherent redundancy in having 2 100Ah packs. If a cell goes bad in one of the packs, you still have 100Ah of capacity to get by on. If a cell goes bad in your single 200Ah string, you’re SOL. “Two is one, & one is none.”

I used to think folks that put heatshrink on all of their tools were just being “safety sallies”, until I dropped a wrench across my bus bars. Now my battery tools are either cut short to not reach adjacent busses, or wrapped in tape.

Svetz, I believe he meant “shore power inlet” vs. outlet on the RV.

It was a good deal at the time. If I could start over, I'd buy 280ah cells. My cell selection did not affect other equipment choices. I've been following @BiduleOhm design of a new BMS here.

Interesting. I'll try the same experiment this weekend to see if the framing errors are an "undocumented feature" and the Mega is masking them, or if it's specific to your unit. What is the cable distance between the BMS, your inverter ckt, and the Mega?

There are 10 kinds of people in this world: those who understand binary, and those who don't.