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Re: The 40KWH Battery Topic

Posted: Wed Oct 17, 2018 12:19 am
by kovadam
The BMS is on the left side (driver side for non UK cars), it is visible also in older videos and in the new 40kWh dismount video made by EVs Enhanced. However none of those videos/pictures can you see such a device on the right side of the battery pack. Inside there is nothing just a vertical holder which holds the read battery line.

A fan would be good there to vent the hot air out from the battery pack in case the ambient air temp is lower than the inside temp of the battery pack. If you continuously remove the hot air, it will help to reduce the battery pack temperature to ambient temp in a short period of time (like 1-2 hours depending of the temp difference between pack & ambient air temp). Of course it is only working for milder climate, not for hot desert, however parking the car in a cool place (A/Ced garage, etc), could help to reduce the battery pack temperature. The problem is the condensation what you might get if you let outside air inside the battery pack...

Re: The 40KWH Battery Topic

Posted: Wed Oct 17, 2018 7:33 am
by WetEV
kovadam wrote:A fan would be good there to vent the hot air out from the battery pack in case the ambient air temp is lower than the inside temp of the battery pack. If you continuously remove the hot air, it will help to reduce the battery pack temperature to ambient temp in a short period of time (like 1-2 hours depending of the temp difference between pack & ambient air temp).
With a large enough fan, sure. Perhaps you might calculate how large the fan is needed?

Note that as the temperature difference gets smaller, the amount of heat removed gets smaller. So you might halve the temperature difference in X time, quarter it in 2*X time, 1/8 in 3*X time, 1/16 in 4*X time... Never goes to no difference from ambient, unless ambient temperature changes, of course.

Re: The 40KWH Battery Topic

Posted: Wed Oct 17, 2018 4:47 pm
by GRA
WetEV wrote:
kovadam wrote:A fan would be good there to vent the hot air out from the battery pack in case the ambient air temp is lower than the inside temp of the battery pack. If you continuously remove the hot air, it will help to reduce the battery pack temperature to ambient temp in a short period of time (like 1-2 hours depending of the temp difference between pack & ambient air temp).
With a large enough fan, sure. Perhaps you might calculate how large the fan is needed?

Note that as the temperature difference gets smaller, the amount of heat removed gets smaller. So you might halve the temperature difference in X time, quarter it in 2*X time, 1/8 in 3*X time, 1/16 in 4*X time... Never goes to no difference from ambient, unless ambient temperature changes, of course.
H'mm that's quite a paradox, Zeno! ;)

Re: The 40KWH Battery Topic

Posted: Wed Oct 17, 2018 7:03 pm
by LeftieBiker
H'mm that's quite a paradox, Zeno! ;)
And in this case it really dose prove that Nissan packs never cool off.

Re: The 40KWH Battery Topic

Posted: Sat Dec 08, 2018 11:52 pm
by krox
Is it possible or not to replace the 24 kWh battery in the old Leaf with a new 40 kWh?
Is there any official document from Nissan on this issue?

Re: The 40KWH Battery Topic

Posted: Sun Dec 09, 2018 12:02 am
by cwerdna
krox wrote:Is it possible or not to replace the 24 kWh battery in the old Leaf with a new 40 kWh?
Is there any official document from Nissan on this issue?
LOL. There isn't even any official document or support for replacing with or installing a 30 kWh battery into a 24 kWh Leaf. Nissan's already said no multiple times.

Given that, I wouldn't hold your breath for 40 kWh pack into a 24 kWh car.

Re: The 40KWH Battery Topic

Posted: Mon Dec 10, 2018 8:01 am
by krox
Thank. Where can I read this information (about the inability to replace the batteries) from the official Nissan? Give me a link.

Re: The 40KWH Battery Topic

Posted: Mon Dec 10, 2018 12:38 pm
by cwerdna
krox wrote:Thank. Where can I read this information (about the inability to replace the batteries) from the official Nissan? Give me a link.
Re: no on 30 kWh batteries for 24 kWh cars, see below.
https://transportevolved.com/2015/09/11 ... san-leafs/
https://transportevolved.com/2015/11/03 ... -answered/

I was at a meeting years back with a Nissan corporate marketing guy and the request was conveyed repeatedly by some folks. This was back before the 40 kWh Leaf existed but the 30 kWh had been out for a bit.

Some folks basically felt, "if I was going to pay full price for a replacement battery, why would I want to buy a 24 kWh battery? I'd rather pay a bit more and have a 30 kWh pack." Or, "if I'm going my 24 kWh battery replaced under warranty, can't I pay a bit more and get a 30 kWh pack instead?"

Re: The 40KWH Battery Topic

Posted: Fri Dec 14, 2018 12:12 pm
by DaveinOlyWA
krox wrote:Thank. Where can I read this information (about the inability to replace the batteries) from the official Nissan? Give me a link.
Nissan "won't" do it and yes, its possible but would require a LOT of money. More money than its worth especially to gain 6 kwh.

Re: The 40KWH Battery Topic

Posted: Sun Jan 06, 2019 6:57 am
by krox
Soon a video will be released on YouTube, where we installed a 40 kWh battery on the Leaf 24 kWh. See what came of it. :)
Hi Nissan!