Daklein said:Added pictures of the covers here: https://photos.app.goo.gl/tcVLm3SHCtozeLSa6
Did you measure your clearance before and after battery swap? You definitely don't want to hit the battery on e.g. higher-than-usual speedbumps!
Daklein said:Added pictures of the covers here: https://photos.app.goo.gl/tcVLm3SHCtozeLSa6
nlspace said:Where would the heat come from--a stack of cold cells sitting all night?
When the battery has excess heat, the odds are very good you don't need to heat the cabin. Almost no gain.Andrey said:nlspace said:Where would the heat come from--a stack of cold cells sitting all night?
When you start driving, battery is heating up, don't you think? I'm not talking of getting warm air immediately - you don't have a choice except of turning AC in heat mode or use electric heater. But when you drive you can use heat from batteries, not just dissipate in the air, and stop using other heaters.
mux said:I would HIGHLY DISCOURAGE blowing ambient air into the pack. Condensation will cause massive issues over time.
These battery packs are purged with super-dry air, often even just nitrogen/co2/argon to make sure that if temperatures drop, no moisture will condense inside the pack in inconvenient locations. This is an issue any time the battery comes close to the dew point, which can be any temperature under roughly 17C, depending on how much moisture is in the air inside the battery pack.
Once condensation forms, you can get rust on the compression frames, cause shorts or low resistance paths on contacts, etc. It's a major cause of battery fires in early EVs (although much less prevalent recently).
And you don't need to either. It's already a big help if you just mount a (fairly strong, it has to move air through tiny spaces) fan inside the battery enclosure, then reseal it and flush it with nitrogen or co2 and a bunch of silica gel packets. Circulating air inside the pack will even out temperature differences, which will even out the internal resistance of different cells and alleviate a lot of weak cell behavior.
We've been thinking about how to do a 'proper' thermal management system for the battery. Considering the battery already has heaters in most areas where the Leaf is sold, that part is easy. Cooling it is harder. It's probably inevitable that you would need to cut a large hole into the battery enclosure and weld/glue/bolt on a big extension piece that houses a heat exchanger and fan to cool the battery. Then add a separate controller for the heater pads inside the battery that doesn't suck balls. Not an easy mod to do, but the only way to do it properly.
Hmmm. So all you need to do is design and build your own BMS, assemble your own battery pack, and build a complementary battery cooling system. Ah, how many of us are likely to do those things in our garage (rather than buy a newer EV with more capacity)?brunohill said:If you could reprogram the BMS/LBC (or replace it with your own) for a more energy dense battery chemistry, then you could replace the batteries with something physically smaller, maintain or increase your capacity and have room for some form of cooling.
Dooglas said:Hmmm. So all you need to do is design and build your own BMS, assemble your own battery pack, and build a complementary battery cooling system. Ah, how many of us are likely to do those things in our garage (rather than buy a newer EV with more capacity)?brunohill said:If you could reprogram the BMS/LBC (or replace it with your own) for a more energy dense battery chemistry, then you could replace the batteries with something physically smaller, maintain or increase your capacity and have room for some form of cooling.
mux said:I would HIGHLY DISCOURAGE blowing ambient air into the pack. Condensation will cause massive issues over time.
These battery packs are purged with super-dry air, often even just nitrogen/co2/argon to make sure that if temperatures drop, no moisture will condense inside the pack in inconvenient locations. This is an issue any time the battery comes close to the dew point, which can be any temperature under roughly 17C, depending on how much moisture is in the air inside the battery pack.
Andrey said:Daklein said:Added pictures of the covers here: https://photos.app.goo.gl/tcVLm3SHCtozeLSa6
Did you measure your clearance before and after battery swap? You definitely don't want to hit the battery on e.g. higher-than-usual speedbumps!
Oilpan4 said:Hyundai appears to be circulating cabin air through their hybrid battery.
DougWantsALeaf said:I am still curious why Nissan didn’t try to put at least a fan with the 62 pack. Admittedly, even running hundreds of miles on very hot days and fast charging didn’t hit an issue. I just don’t know yet whether it will lead to a faster battery decline.
Oilpan4 said:Hyundai appears to be circulating cabin air through their hybrid battery.
That's the thing with water. You think something is sealed up well enough to keep water out, but only sealed up enough to not let it back out.
Today relative humidity is 14%. That's normal for winter.
DougWantsALeaf said:I am still curious why Nissan didn’t try to put at least a fan with the 62 pack. Admittedly, even running hundreds of miles on very hot days and fast charging didn’t hit an issue. I just don’t know yet whether it will lead to a faster battery decline.
Rodriguez said:I tried to search this thread, but apparently the words ''charging'' and ''charge'' are too common and the forum doesn't want to return a result.
I was just pondering, if we'd assume that the DC inlet, cabling etc is up to spec to receive more power than 50kW would it be possible to trick/hack the car to getting a higher charge rate if the charger can supply it? With a 50+ kWh pack the battery doesn't get stressed that much as it used to.
DaveinOlyWA said:DougWantsALeaf said:I am still curious why Nissan didn’t try to put at least a fan with the 62 pack. Admittedly, even running hundreds of miles on very hot days and fast charging didn’t hit an issue. I just don’t know yet whether it will lead to a faster battery decline.
No room. It was already a challenge getting the 62 kwh pack to fit (this is why they were released late.) So adding more stuff w/o a complete redesign would not have happened. I am guessing they "could" have done it to the 40 kwh pack with the advanced cell design but felt that is was a different driving segment and I agree on that point.
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