SwampNut

LOL, well yeah, it's being worked on. The printer fucked up when switching from PLA (low temp, fast modeling/test parts) to ABS (solid, heatproof), so I have nearly three hours of printing before I can assemble this.

My solution for the roll-away problem... Also, after many hours of usage, still 100% satisfied and recommend it. Now to convert the old shitty chair into a rolling tool/parts holder. I'll probably just cut a plywood circle as a top, maybe with a magnetic sheet to keep things stable/in place.

I'm now motivated to just replace the Smart battery BEFORE it fucks me over. It's...I can't count now, but very old.

It came with a lead-acid that has been "bad" for a year or two now. I did a second restoration run and it seems to be holding on, it won't get another one. As a Jewban I can't force-kill something that is kinda working to crank that 0.89 liter bottle of horsepower fury. I also have not ever seen a cell rated for the same out as in. My hobby LFPs are ridiculously different. Something in the order of 10-15C discharge and 1-4C charge.

Will one of you niggers make up your minds before I eBay it? FUCK

They seem to be fine in our heat, and if your battery is frozen you need to solve it with the help of U-Haul.

Yeah it looks like the drop in replacements have a cutoff, but not a limiter. Unlike things like the e-bikes.

Three different LLMs agree that this is a problem for a bank of batteries, not one battery in a car. HOWEVER, it also said that if you have a very high output alternator, you could exceed the recommended charge rate on a small battery. Bottom line For a single 100Ah LFP replacing a starting battery in a normal car with a stock alternator (~100-150A), the risk is moderate — the alternator's internal resistance and the car's electrical loads naturally limit the current somewhat. For a dedicated house bank charged directly from the alternator, a DC-DC charger is genuinely necessary, not optional.

I've never measured a car/moto/RV battery, but for sure, the BMS in other things like the e-bikes controls the charge current and ramps it up/down. With some I can use an app to force a change within safe limits. "Doesn't add resistance" is pedantically accurate, but what it does do is reduce the voltage until the current goes down. (Basic electronic principles.). Even my benchtop power supply with battery charging has this. Now I need to do more research, but it would make no sense that the BMS could allow unlimited current.

While valid, in my marginal research on this specific thing so far, it should be built into the BMS for a normal load range. Meaning, if you use one "normal" size LFP for a car let's say, its BMS should be limiting current. It would be a problem for something like an RV where you parallel multiple batteries. Do you see it differently? It would probably be cheap to get a massive 0.5 ohm resistor to put in line and limit the current without limiting terminal voltage. (Terminal as in final, not as in the battery terminal.)

Ok, it *is* using FM. I've owned (old) testers that actually did test real current. Looks like these use an estimation method, which is why you get wildly varying results in different cases/metals. Claude Pro: The AC Conductance Method (Electronic Handheld Testers) Most modern shop testers don't clamp the cable — they use AC signal injection to estimate CCA from internal resistance. Conductance testing sends a small AC signal at a single frequency through the battery and measures how it reacts, effectively checking how hard it is for electricity to flow inside — the internal resistance. If resistance is high, the battery isn't working as well. Rotronics An AC conductance tester injects an AC signal between 80 and 100 Hz into the battery. It sees the components of the battery's circuit as one complex impedance, with the majority coming from the first resistor. UnderhoodService At around 90 Hz, electrical noise — both capacitive and inductive — levels out, so the meter gets a clean read on internal resistance. Rotronics Handheld testers induce a momentary high-current pulse that corresponds to the entered CCA value, and Ohm's law calculates the internal resistance from the induced voltage drop. The device then provides a CCA-equivalent reading. Battery University Accuracy Limitations Accuracy has always been in question, and CCA is especially difficult to verify because readings are affected by state of charge, temperature, and other factors. Battery University The battery's temperature could skew results, though most advanced modern testers compensate for this. Rotronics Additionally, a fully charged battery that maintains its CCA rating might still be nearing the end of its useful life UnderhoodService — CCA alone doesn't tell the whole story of battery health.

I was unsure what you were asking before. Most of these testers have a way to put a load on the battery. As Chris said, resistors. Very likely to have a low duty cycle.