[jve]

> deep-cycle discharges below 60% full cuts usable charge cycle counts from 8000 to under 2000 uses.

That is, if you do it single time you are down from 8k to 2k? Or it decreases gradually and 2k is the worst case?

Where can I read about it? Not a paper, but something more down to earth for consumers? That is, for a consumer to know how to properly maintain various devices (phone/car) for longevity?

[magicalhippo]

Keep in mind that for a car, 2000 cycles is still a fair bit. My BEV has a range of 350 km fully charged (highway). At 2000 cycles that's 700000 km.

That said, I previously read studies suggesting to keep the batteries between 30-70% SOC for optimal longevity, though I imagine there's been a lot of research so it might be now outdated.

[Joel_Mckay]

Some older Tesla Models used the Panasonic 21700 cells.

In general, "the battery is the car" for EVs... The bigger the better in my opinion, as it will last longer due to reduced stress on the cells.

Even if people are stressing the vehicle pack, they should still get 5 to 12 years out of the car. Note, some companies hide the expected range loss by over-provisioning capacity.

Best regards, =3

[jajko]

> The bigger the better in my opinion

This is definitely true, recently faced issues with my motorbike battery and oh boy are they fragile and lose charge by themselves quickly compared to bigger car batteries.

Basically I left a few times older (10-15 years) diesel bmw standing whole winter without touching it, started always without any issue (I know not the best idea re fuel in the tank, but it worked).

I did that once to completely new motorbike (honda) with good brand battery but I didn't unplug it, and now battery is permanently damaged and loses full charge in less than 2 days to such levels that it can't start the engine even if those 2 days its completely unplugged.

[Joel_Mckay]

Motorbike Pb AGM batteries are much different in modern vehicles. The prismatic packs often increase the plate surface area to bump cranking amp ratings. Thus, the cells design are thinner and more fragile too. We used these in some equipment at one time, for the extended temperature range.

Tip: if a Pb pack is partially discharged, it is more vulnerable to cold-weather related standby failures. Most people that own boats/heavy-equipment get a plug-in trickle-charger for Pb batteries, as the adapter also helps keep the pack slightly warmed.

Best of luck, =3

[Joel_Mckay]

The problem is there are many different types of Li cells. Some tolerate a wider Safe Operating Area for power output and temperatures.

I don't want to get into the name-and-shame game with other manufacturers. The 3 brands mentioned are generally very good quality, and if you can source new cells without counterfeit/expired nonsense... they will perform as per their app notes.

The cycle limit is a function of whether your charger IC is smart, slow-charge/low-current-discharge, and if your firm uses capacity Boosting (stress costs cycle counts.)

>Or it decreases gradually and 2k is the worst case?

Anecdotally, sensitivity seems somewhat correlated with cell use/age. The more stress, and the faster the cell degrades.

Best of luck, =3