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Also you can check out this: https://diysolarforum.com/resources/youlovesolar-wire-size-calculator-highly-customizable.387/

Update: Only done a couple dozen cycles so far. Always kept SoC between 50% and 90% SoC while stored in climate-controled space. I still have the version with the 1st gen (?) BMS. Result: Extremely out of balance, only 3.6 out of 5.1 kWh available. 🤨 Replaced with JK BMS 200A 2A active...

Per request of @Pi Curio, 10 Heschen fuses (sourced on Amazon; HSPV-30; 32A; 1000VDC; I1 = 33kA) were blown while mounted in their DIN-rail fuse holders (sourced on Amazon) in the vertical position. These fuses are filled with sand, similar to Class T fuses. The resulting current versus time...

Today two more 22 AWG copper fuse wires were blown, similar to the previous black curve. The 22AWG copper wire fusing current is approx 41Adc (Preece), so this is a relatively small fuse having a clearing (blowing) time that is at the lower end of what I expect to be used in practise. Goal...

Thanks everybody a lot for the input. Feature requests so far: Create current versus time plot, e.g. using an oscilloscope / clamp meter with inrush (the latter has too low max current). Test more fuse types: Class T (example); bs88; NH; 300A MEGA; CNL; South Bend. Test breakers - cheap amazon...

Another data point: I just dead-shorted a 150A MRBF fuse using 330Ah 48V LFP and 4/0AWG cable. Results are here.

Another data point: I just dead-shorted a 150A MRBF fuse using 330Ah 48V LFP and 4/0AWG cable. Results are here.

Another data point: I just dead-shorted a 150A MRBF fuse using 330Ah 48V LFP and 4/0AWG cable. Results are here.

Introduction Marine Rated Battery Fuses (MRBFs) are sometimes used to replace Class T fuses due to supply chain issues, ease of installation, space constraints, and cost. However, the breaking capacity of MRBF fuses is significanly lower than that of Class T fuses as shown in Figure 1. Figure...

Added NEC 250-500 kcmil wires Added Aluminum material Added periods to version numbering

Problem It's very annoying when yet another expensive and hard to source class T fuse blows. So how can we visualize why they blow? The graph below may explain why Class T fuses blow due to the inrush current from a (for example) LFP battery to an inverter. It may also explain why taking a fuse...

Improved comments for when running multiple wires in parallel Readability improvements "under the hood"

Improved UI Added feature to run multiple wires in parallel

Made conductor resistivity dependent on the wire insulation temperature rating.

Resistivity increases with temperature. The used conductor resistivity was optimistically low (corresponding to 20degC). To be more conservative, the resistivity is now chosen higher, corresponding to 75degC, roughly conform NEC chapter 9, tables 8 and 9. So for a given max allowable voltage...

Opening the sheet in Google drive corrupted it. Other minor updates: changed default values to more common values

No longer switch between multiple tables: Choose the right wire for your custom allowable voltage drop while simultaneously taking into account ampacity, temperatures, and bundling. Click the orange button at the top of the screen to download the Excel sheet (safe: no macros / VBA code). See...

@chrisski @RCinFLA: Related to this, see also: https://liionbms.com/php/wp_resistance_vs_impedance.php

Price: $2100 The price is for one battery. I have four in total. Reason for sale: Intended for training, but that was canceled, so they have never been used. Warranty: These batteries have a limited factory warranty of 3 years, starting on 2023/08/21 and ending on 2026/08/21. Shipping: USPS...

Unfortunately I do not have time right now to swap BMSs. I sold the EG4 charger and bought a Wanptek KPS6020D (max 60V, max 20A) on Alibaba for charging to 3.40Vpc. *So far* no cell exceeds 3.65Vpc, the SoC "only" reaches 99%, which is fine for me now.

Sold.

Price: $133 Local pickup or shipping from ZIP 95818 available. Buyer pays for shipping. Reason for sale: Switching to bench top power supply for more flexibility. Condition: as good as new (used only once, successfully). I replaced the ring lugs by an Anderson SB175 connector (can be replaced...

Update: The BMS increased* the imbalance (wtf) instead of decreasing it, so I decided to take the cells out of the case and manually balance them individually using two parallel 3 Ohm (actually measured less 1.8 Ohm) resistors. Took me a whole bunch of manual actions spread out over a couple of...

So far I can only tell you this (quick and dirty): The balancing LEDs sometimes turn on when I do CC-CV-charging to 54.26V (roughly 3.4V per cell on average). This battery voltage was read from the app, which matches my power supply @ 0.1V difference. However, sometimes they did not turn on at...

@Dutchie - Zelf bouwen is het goedkoopst. En anders gewoon een server rack vol stouwen met deze: https://signaturesolar.com/shop-all/batteries/

It feels like a soft rubbery caulk (so not hard like cured general purpose epoxy), like white silicone caulk. Maybe it is intended to prevent or delay the onset of loosening from vibration as discussed here: https://electronics.stackexchange.com/questions/236457/white-glue-on-circuit-board...

I am trying to balance first. See below the LEDs that may indicate balancing cells, this was yesterday, 7 of the 16 are on. This morning only 3 were on. The PCB is 10-20F warmer around those LEDs where the balancing resistors likely are. I manually keep a cell-level voltage log in Excel to...

For me, charging 24h with the EG4 charger did not revive the BMS. I should recreate the problem and then try it with my bench top power supply. Other "solution" to get the BMS out of protect mode: https://diysolarforum.com/threads/signature-solar-eg4-wp-teardown.39768/

This post shows how I opened the case of the EG4-WP 48V 100Ah (5.12kWh) battery without damaging any cells or other electrical components. This voids your warranty. First try to contact Signature Solar to see if a less invasive solution exists. In my experience they do their best to help you...

@sed6: What is the maximum balancing current that you used? 5A? Also, what wire gauge are your Tesla module balance leads?

Interesting, do you have a link to the specsheet of the UVR ("Under Voltage Release" I assume)?

Yes! Nice! Seems an excellent charming solution to me! Thank you!

In his most recent use with the ATF, David Poz, like you, also correctly left out the dedicated breakers for the ATF. It's difficult to see in the video, but the ATF is directly (i.e. no breaker) connected into the wire nuts (instead of bus bars) as shown in this still: I think this makes...

@smoothJoey @uzernaam: How about a breaker instead of a (class T) fuse? A breaker can be easily reset. A breaker can also trip faster in the range of 125 to ~300% of the rated load as shown in the figure below (yet still allowing some inrush currents), and breakers can trip slower above ~300%...

Here is an example of out-of-the-box SolarEdge autotransformer short to ground: In you case, such a short could trip the 30A double pole AC breaker, in turn also shutting off all 120V loads, reducing (removing?) the risk of a "floating neutral", so your 120V loads are probably better...