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V2g has a a few challenges of course but people seem to not be aware that their EV batteries are much better than they think. The early ones from ten years ago
by jillesvangurp 4y ago
V2g has a a few challenges of course but people seem to not be aware that their EV batteries are much better than they think. The early ones from ten years ago had no battery management systems and had issues with wearing out relatively fast. But the newer ones have battery management. So, the wear and tear is a lot less these days.
A typical car battery is rated for thousands of cycles. 3000 cycles is a number you hear often. If you have an EV that has a range of 300 miles, we're talking about 900000 miles. That's more miles than the vast majority of cars will drive over their lifespan. The average driver drives less than 15000 miles per year. The car will die before the battery typically, not the other way around. And the battery isn't completely dead at that point, it should still be good for 80% of its original charge. The vast majority of EVs ever produced are still driving with their original batteries and will be for years to come.
A second point is that EV batteries are designed to discharge in a few hours to drive the car. There is no way you'd discharge at that speed via v2g. Most home connections charge/discharge only at a few kw. It's a comparatively light load for the battery and the wear and tear is pretty modest. Battery degradation happens a lot faster if you stress the battery. There are some indications that suggest that v2g discharging has only a very minimal impact on battery life. You wouldn't fully discharge the battery. Not even close.
A third point is that with smart chargers, you would be able to control when the battery is allowed to discharge and how much. A million cars contributing just a single kwh each is 1 gwh. That's a huge amount of power. You would not fully cycle the battery typically but maybe only a few percent. If you start with 3000 cycles and you use 10% of that every day (which would be a lot), you could do that for 30000 days. That's longer than most humans live.
Finally, instead of providing power to the grid, you could use a system like this to power your house and make save significant amounts of money in the evening by using your car instead of expensive grid rates using power that you got from your solar panels during the day for free.
Those savings can really add up over the years. If it worries you, you can invest in a house battery instead. In the end the argument has to be financial and v2g is probably cheaper overall than that. People are spending tens of thousands of dollars to put solar on their roofs. So, throwing their car battery in the mix is a comparatively small step and a perfectly rational thing to consider. But the numbers have to make sense for people to opt in to that.
- deleted 4y ago[deleted]
- sieabahlpark 4y ago[dead]
- Eisenstein 4y ago> The early ones from ten years ago had no battery management systems I think you misunderstand what a battery management system is. If a Li-Ion battery had no BMS -- especially one that is large, high power, and composed of many cells, it would literally be an incendiary bomb if not carefully managed by the user. The BMS is responsible for maintaining the cells -- they must be equalized and cannot go below or above certain voltages, and the charge controller is not the unit responsible for doing this while the pack is in use. By claiming that there were no battery management systems in earlier EVs you are showing ignorance about the workings of these systems to the point where it is difficult to trust the other things you say. What is your background for this knowledge? Can you provide references to your claims?
- jillesvangurp 4y agoThe Nissan Leaf had no battery management system when it launched. Many similar cars from that era lacked a BMS. E.g. the Renault Zoe and a few others. I'm not sure about the early Teslas. I think they saw the need for a BMS pretty early. I think you are just playing semantics here. Obviously they had some simplistic controls on the electronics. But no smart distribution of load, cooling systems, etc. Calling people ignorant is not nice BTW. Says more about you than me. Insisting on references is also a bit weak. Where are your references? I suggest you do your homework with some Googling and then come back to apologize. Would be the nice thing to do.
- DoingIsLearning 4y ago> Nissan Leaf had no battery management system when it launched. Citation needed? As far as I know even the 2012 Leafs had a per cell thermal management. I think in the earlier Leafs a lot of the intelligence on charging operation and battery cooling/heating was offloaded to the BCM module but it is a bit of a hyperbole to say that there was no battery management. They may not have had a dedicated BMS module in the OEM sense of BMS (like what Infineon now makes) but they certainly had temperature/charge management controls.