James Broadhurst
100 W
The only way I can get an 80% charge into a Li battery is if I start with the battery fully discharged or near enough. Within +5/0 minutes (it's never faster than 60 minutes) I can hit 80% which presupposes I've towed the car to a charger as there isn't a BMS car system around that will allow a battery to be discharged completely. With a 10% residual charge, although you can reach 80% in less than an hour, you will not reach 90% for 90 minutes or so. This means that under any normal condition you can not put 80% into a battery within an hour.
The problem is that irrespective of what value of constant current I start with, as soon as the voltage reaches 4.2 the current rapidly drops off. You can move that transition point backwards or forwards but what you gain in one charging phase, you lose in another.
The batteries I tested were Samsung 30Q & 35E, LG MJ1; all of which performed as per their data sheets although an 80% charge becomes a difficult to achieve target the more cycles you put it through. The 35E is alone in having a maximum charge current considerably less than 1C.
I ask this because here in Europe many governments, even down to the lowest parish council, are wanting to ban combustion engines in 10 or 20 years time and in the 10 years that I've been involved in this, the rate of technical progress (as measured in energy capacity) has been miserable. All good virtue signalling to the voters but it isn't going to end well at this rate.
The problem is that irrespective of what value of constant current I start with, as soon as the voltage reaches 4.2 the current rapidly drops off. You can move that transition point backwards or forwards but what you gain in one charging phase, you lose in another.
The batteries I tested were Samsung 30Q & 35E, LG MJ1; all of which performed as per their data sheets although an 80% charge becomes a difficult to achieve target the more cycles you put it through. The 35E is alone in having a maximum charge current considerably less than 1C.
I ask this because here in Europe many governments, even down to the lowest parish council, are wanting to ban combustion engines in 10 or 20 years time and in the 10 years that I've been involved in this, the rate of technical progress (as measured in energy capacity) has been miserable. All good virtue signalling to the voters but it isn't going to end well at this rate.