With everything I have read from VW, and my lone one size sample personal observations, everything F1 has posted has matched my experiences in almost 4 years of ownership. We haven't gotten to the point of 7 or 8 years in service e-Golfs yet, but I highly doubt VW will cover very many of these batteries under warranty, and have to replace with a 70% capacity or slightly better battery. They are quite conservative, so my guess is the buffer in the battery pack is enough for them to get them through warranty coverage almost all of the time, save a few battery packs that have some cell packs just die, due to heat or old age, or abuse.f1geek wrote:1. I believe that degradation is not linear, but is more likely hyperbolic ( from the data I’ve seen for Tesla packs), so while the initial loss rate may be high, the loss rate should decrease as time passes.
2. The e-Golf pack has both a top and bottom buffer, so 100% SoC is not equivalent to 4.2 Volts per cell, and you can’t fully discharge the pack, thus providing some protection.
3. Based on the names of some variables I have observed in OBDEleven, I believe the BMS is programmed to reduce the top and bottom buffers so that the net capacity can increase (at the expense of longevity) and help the pack to remain above 70% at the 8 year or 100,000 mile warranty limits.
4. I believe VW did heavy testing on the pack and has data (as well as the potential strategy in point #3) to give the company confidence in providing said warranty without needing to replace a significant proportion of e-Golf packs.
5. If the warranty is triggered, VW promises to NOT replace with a new pack, but with a pack at 70% net capacity.
6. Based on points 1 through 6, I believe the prudent owner will not deliberately abuse the pack as the chance of replacement with a new pack is low. Instead, accept that the pack will lose capacity, but probably no more more than 20 to 25% at the warranty mileage and time stipulations.
Volkswagen is notorious for their dealerships denying warranty coverage for anything, because VW pays dealership shops so poorly on warranty work. So the dealership has every single incentive to deny warranty coverage, and get the customer on the hook for repair and replacement at full dealership hourly rates for labor, and profit on parts to improve their profits and their bottom line, at the customers expense...
IMHO, you really need to know more about your e-Golf and it's electrics than the service writer or technicians, before you go in requesting repairs. The service writers have a very annoying habit of forgetting to log your complaints on the forms, so you have to verify everything they write up, and make changes or amendments BEFORE you sign your name on the line, make sure everything you talked about is there, and written up. I go in with a written list of my own, before I take any of my VW's in for service. I then compare my list to their write up. They are pretty sneaky about what they DON"T write up that you've made a complaint about. Or they say they can't duplicate the problem or they've never heard of it happening before.
I haven't had very many warranty issues with VW's yet, but the few times I have, it's been a royal PIA dealing with any VW dealership and having to go through VW Customer Care to get the problem resolved under warranty.