im probably going to disappoint you.. those compression end caps is just one layer of duct tape wrapping around with a piece of hardwood at the ends.Wow, great looking battery!
The time spent wrangling the rats nest paid off!
Those compression end caps look interesting, do you have any more pictures?
Did you put any insulation between the cells?
I'd agree with Bob, I'd hunt for a different solution on the bus bars.
What's with the multiple small wires in and out of the switch (?) on the lower left end of the positive bus bar?
Just want to show it to someone.
Not like any of my real life friends would understand it
I put in more work into making a rat nest of wires into art than a sane person should lol.
Bad and good critique is welcome
I take issue with the second point:
"Average of two cells"
The cell pairs are bolted to each other positive and negative. There is no need to average, they will be the same voltage. Exactly the same as far as I am concerned.
Well, the same voltage once the pair have balanced to each other.
I will not dig into the 2p16s vs two separate 16s packs in parallel. That feels more like personal preference to me as long as we are talking new cells, all of the same spec/from the same vendor.
I could have missed things too (I saw a free nut ... but on top on the glass so no problem )I can't believe I didn't notice the lack of over current protection, good point.
Hi mrzed. Alot of good pointers there.That plexi/glass top is something new, but i like it
OK lets get the check list (you can fill in the missing answears ):
Good, bad, everything is here
- Cell compression, method? Check. (metal bar maybe, can not see, more info?)
- Cells setup? In this case 2p16s setup (2 parallel and then 16 times this serial). Not ideal but can work. BMS would only saw the average V of 2 cells.
- Did you do a proper top balance of the cells ? What were your procedures, how did you do it ?
- Copper busbars on alu terminals. That is not ideal at all. Did you use noalox or carbon grease ? Terminals polished ?
- Terminals, connecting elements, order? Grub screw OK. Balance lug not under the washer. BMS can get inaccurate V values from cell pairs.
- What was charging the battery ? MPPT or PWM solar charge controller or an utility charger? Size, Type, connected solar panels number, Voc, Vmppt, Amppt ? Charging settings (bulk V, absorption V, float V, max charging current) ? MPPT charger, not too strong (below 200A)
- What was discharging the battery ? Inverter (size, type?), direct load ? Max discharging current/watt estimate ? inverter not too strong (lower than 10kW)
- Non conductive separator between the cells ? No
- Standing on a non conductive base?
- Cells placement? Shed, garage, inside/outside? On the ground, on shelves, ... ? Battery is how protected from fauna (rodents, bugs) and flora ? IP11 protection max : bugs, lizards, rodants can get in ... almost protected from spilling water.
- Ambient temperature? Cells and busbars temperature in high load/charge (hand test not warm is OK) ? Any extra cooling like fans ?
- Humidity? Pipes near the battery, MPPT, inverter? Possible water, steam or condensation in the area?
- Cable size/type to BMS and after that? Fuse after BMS on both cable, size? No fuse after BMS (on both cable). Only switch or braker on +. AWG2 cable is enough for this small inverter and MPPT.
- Usage of the battery? Constantly charging, lot of time on max charge (SoC >95%)? Lot of time in minimal charge (SoC<10%)?
- Where the battery floated? So SoC >95% and float V > 3,4-3,45V/cell ?
- BMS is Daly. Which type, how many A? Cell Volts in Daly the same as by measured with a multimeter? Daly 200A LiFePO4. More than enough.
- Busbar to connect all equipment? Check. I have no problem with that But a mini busbar with cover would be better.
- Fuse on PV cables? Only breaker
- Shunt to measure battery current SoC? Shunt on solar input. No info about battery SoC.
- Ground bar, ground rod? Ground bar present and connected
- AC breaker/fuse ? Not present.
- AC RCD? Not present.
- AC grounding? Present, but not pretty.
- Any contingency in the case one cell vents toxic fumes?
- Any fire alarm or fire extinguisher ?
BecauseHi mrzed. Alot of good pointers there.
About the fuse, I must get a fuse as close to battery positive as possible before Murphy decides to throw a wrench at exposed bus bars but..
Why would a fuse be needed when ssc and inverter have built in fuses and if every conductor is isolated between battery and ssc/inv? I know for a fact the epever ssc and inverter i got have fuses built in.
About the balance lead ring terminals being optop instead of below the washers. Can you eleborate on how that can that make a difference in voltage reading? I would love to have the balance leads below washers but the washers reached beyond the heat shrink of balance lead making uneven contact
But only on 1 legInstalled 150amp anl fuse
Excellent. You achieved IP22 protection https://en.wikipedia.org/wiki/IP_Codeand covered up the main neg and pos.
ExcellentFixed balance lug nuts so they are below washer not above
Can you check this question about wiring 2 inverters via same 3 phase rcd?But only on 1 leg
The - needs one too, after the BMS (now if a BMS P- has a contact to busbar on top is not a problem ... after that it is )
Excellent. You achieved IP22 protection https://en.wikipedia.org/wiki/IP_Code
You know, there are other red marked items on the list too. And some yellow
And a lot of unanswered questions