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...
Calculation model description
This thread focuses on the calculation of an approximate estimation of the maximum C-rate for a given battery and/or the cell temperature (increase) at full (dis)charge for a given C-rate.
It is conservatively assumed that heat cannot escape from the battery...
Here are two teardown videos of prismatic LFP cells. This can (or not?) be useful when accidentally stripping the terminal threads and considering strategies for repair (or not). Feel free to add more, especially for the "blueys".
1) CA180FI (I think - specs).
Screenshot of the aluminium...
The following "Compression Lug Connector" no longer requires dedicated crimp tools:
I just stumbled over these here - includes a video of assembly.
However:
What will a cross-section look like after grinding it open? As done here for example.
Will they operate as "cool" as the traditionally...
Do you want someone else to read a bunch of those time-consuming battery research papers and summarize them for you, for free in a smooth video with fancy animations? Then the following Youtube channel may be something you like:
The Limiting Factor
See for example this excellent video: CATL...
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...
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...
Here is the female version of @Will Prowse:
Sarah Chrisp
Same kind of facial expression, and to the point.
Too bad she probably lives far away otherwise Will and her should go have a coffee ;)
This kind of posts is what you get when you become a public figure ?
Wanted: Damaged or discarded 280Ah EVE cell, preferably one that was sold to you as "new".
Goal: Detailed teardown after full discharge for cell parameter estimation as input for analytical cell model.
Offer: USD 10 (+ shipping if feasible)
Destination: Sacramento, CA, USA. I may be able to pick...
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...
Price: $280 delivered, according to the Costco leaflet that arrived today here in Sacramento, CA:
https://www.costco.com/duracell-3000-watt-high-power-inverter.product.100498909.html
Price @ Duracell: $450
Just sharing, I will not buy it.
Summary
LFP cells from XCell seem to be transcendentally epic in terms of mass energy density (Wh/kg). Has anyone measured the actual maximum capacity and the mass of any cell from XCell? I wonder if the specs from this factory are met in practice and whether they are still as safe as expected...
Does anybody have a simple generic analytical model to quantify the internal resistance of an LFP cell as a function of, for example, the state of charge (and possibly a.f.o. other key parameters like age)? Or do cells differ too much between manufacturers and models so any generic model is...
Can the forum search be extended to accept strings with two or three characters, optionally starting with a number, for example:
"BMS"
"16S"
...and what syntax to use for searches for threads where *all* search terms must appear (e.g. "BMS" AND "16S")?
Maybe a link can be added on the search...
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...