Content by hojnikb in January, 2026

You don't need an active balancer or current limiting on the BMS side. A passive balancer is just fine (and is part of most BMSes anyway), as for current limiting; given that LFPs tend to hold their current flat up to ~90-95%, there's no need for that either. You just cut off charging at 3.65V...

That may be, but you still need less power for a given unit of heat, compared to resistive heaters, which are always only 100% efficient. Even if heatpump runs at 150-200% efficiency, thats still a lot better.

Maybe the charger was limited to 125A for some reason? Either that or the battery was still too cold.

With temps dropping below ~-5C and doing short trips with preheating, i'd be happy to get 100km of range on the 51kwh. Not having a heatpump kills efficiency pretty hard.

Exacly. So do i. Plenty of experience with LFPs and other chemistries. It's just a simple fact, that Na+ just isn't ready for primetim, unless you have a very specific application. Cost isn't an advantage, Wh/kg or Wh/L or equipment compatability neither. It might be a fun diy project, that...

Even if that were true (i run a 3 year old battery and it seems to be near perfect) you'd be still better off with an LFP based replacement. It's operating voltage is closer to lead acid, will offer more capacity for a given formfactor and will have plenty charge/discharge power for an EV...

Fact of the matter is; batery cant pull it's usable capacity with any of the standard equipment, unless especially designed around it. The battery in question doesn't even have a properly setup BMS, so me, as an end user will never be able to pull full capacity, regardless of what equipment i...

That's the dumbest thing i've ever heared. Why would you test a sealed battery at the cell terminals, bypassing the BMS? Nobody in practise will do that (why would they, they bought a battery, not a cellpack). So this was demonstration of the sealed product, not the cells themselfs. Also if...

My home LFP setup, consisting of 16S 280Ah cells (grade A-, since those were they cheapest i could source) still hold near full capacity after roughly 300 cycles. They did degrade initially to about 97-96%, but are still holding that after many cycles. And this pack is heavily abused; being...

So you can tell us what kind of usable capacity you get out of those 200Ah cells, how much power you can pull from them close to 0% SOC and how high is your charge/discharge efficiency? Oh and what kind of degradation you're getting after 12mths. Of course CATL is a big player, everyone knows...

Wattcycle batteries have been pretty well tested by now and very often the recommeded budget battery in the LFP world. And not that -25C is that unreasonable for LFP batteries. It's the charge rate, that doesn't exist below 0C. You can still discharge it, albeit with reduced power. I'm not...

If the DCDC charger is designed with any safety in mind, it will have current limits, so that it won't cook that stock 50Ah lead acid battery. Terminal voltage is just part of that. Your logic would work with an old car with alternator charging the battery directly. In that case, alternator...

https://www.amazon.de/-/en/WattCycle-Bluetooth-Monitoring-Discharge-Motorhome/dp/B0DT4J3PKP?crid=3G3OCQ8WTHM82&dib=eyJ2IjoiMSJ9.gK4uA4Bb9hqene7psRx_vaGvi_t3MAQeNLR1Yw9PX0TcS_AYEYkHclmQuPCT2_ymeu9ijEE85Xg1uQjfOKavDShm_Xa1gDM5fHN8iAzi4RahhJ8XHHZGA2K1_0CM8O5j5T7XSUbxGU0QAixFhvC2srdhml9zVOCB_nf6c-xre...

Most 100Ah 12V LFP batteries are under 10 kilos and are true 100Ah (usually 103-107Ah when new). Lead acid will be at least 30-35 kilos for that nominal capacity. If you include the 50% DoD for safe cycling, that weight goes up to 70+ kilos. If you include additional capacity (since lead acid is...

Sodium ion is crap in almost every way compared to LFP. And they ain't even cheaper than LFP, so no cost benefit either. I'd say there's no chance the onboard charger is charging the battery at 50A. Being that onboard battery is a ~50Ah lead acid unit, it's highly unlikely that it can take...

Too scared to do that without a portable battery of some sorts. As low as i went was to 0% indicated. Still felt it has some juice left in it. I suspect the sub 0% to be about ~1.5kWh, 2kWh tops.

7535U with a Windows 10 VM works flawlessly.

Anyone tried going below 0% on the 51? I'm really curious how much bottom buffer that car has.