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Re: Extra Battery, How to Integrate with 24kWh Traction Battery?

Posted: Tue May 01, 2018 11:20 pm
by alozzy
I'm thinking more of a commercially viable, after market extender solution for mere mortals. I'm hugely impressed by those who are actively pursuing this to extend their LEAFs range, but I have neither the skill nor the time to undertake such a project.

To be clear, I applaud your efforts and am envious that you'll end up with a long range LEAF for a lot less than a 2018/2019 LEAF.

Re: Extra Battery, How to Integrate with 24kWh Traction Battery?

Posted: Wed May 02, 2018 12:19 am
by jkenny23
I think if an aftermarket solution ever does exist, it will be via a newer chemistry/higher energy density battery (and somehow with active thermal management) in the original Leaf battery case, since the modification today requires splicing into either the VCM harness behind the glove box, or at the circular proprietary connector (my original plan) going into the battery, and splicing into the battery to inverter power cable (then running a long heavy gauge cable to the rear of the car).

Re: Extra Battery, How to Integrate with 24kWh Traction Battery?

Posted: Wed May 02, 2018 12:30 am
by IssacZachary
There area aftermarket "solutions" that do exist. Enginer and a few companies selling on eBay have range extender batteries that can be installed in the trunk.

There are also battery refurbishing companies, but as far as I know they only restore the battery to original capacity. Maybe some day someone will do an aftermarket main traction battery with better range and hopefully better longevity.

Personally I would like to get a wrecked Leaf, take apart the battery and sell all the cells (by the sea shore) and the rest of the Leaf except the battery case (or get a good case from somewhere) and then put in whatever cells make the most sense and a thermal management system and then swap that with my Leaf's battery. I would take out my Leaf's BMS and add that as the final component to the DIY battery so there's no need to reconfigure.

Re: Extra Battery, How to Integrate with 24kWh Traction Battery?

Posted: Wed May 02, 2018 1:32 am
by jkenny23
I haven't had a chance to read it through in detail yet, but this is an interesting paper suggesting common high energy 18650 cells can take a lot more charging current than the datasheets suggest, especially if the current is tapered down as the cell charges (which the Leaf does of course), I'll have to compare this to the Leaf QC curve to see how it matches: https://reader.elsevier.com/reader/sd/5 ... A46296BCE2

Re: Extra Battery, How to Integrate with 24kWh Traction Battery?

Posted: Wed May 02, 2018 2:09 am
by mux
IssacZachary wrote:There area aftermarket "solutions" that do exist. Enginer and a few companies selling on eBay have range extender batteries that can be installed in the trunk.
But those are PHEV extenders that charge the car via a charger port, incurring significant losses along the way - not actual permanent extenders à la my car or a couple other forum members. And they don't fix the range shown on the dash, etc. etc.

An actual Leaf extender kit that works as if your car simply had a bigger battery doesn't exist yet, right? Like, I'm developing that right now, just making sure that I'm not reinventing the wheel here.

Re: Extra Battery, How to Integrate with 24kWh Traction Battery?

Posted: Wed May 02, 2018 4:54 am
by mmmike
mux wrote: An actual Leaf extender kit that works as if your car simply had a bigger battery doesn't exist yet, right? Like, I'm developing that right now, just making sure that I'm not reinventing the wheel here.
I don't know what this person https://houston.craigslist.org/cto/d/20 ... 98295.html is doing (or even if it's legit) but it appears the range shown on the GOM is taking into account the extra battery.

Re: Extra Battery, How to Integrate with 24kWh Traction Battery?

Posted: Wed May 02, 2018 5:50 am
by mux
mmmike wrote:
mux wrote: An actual Leaf extender kit that works as if your car simply had a bigger battery doesn't exist yet, right? Like, I'm developing that right now, just making sure that I'm not reinventing the wheel here.
I don't know what this person https://houston.craigslist.org/cto/d/20 ... 98295.html is doing (or even if it's legit) but it appears the range shown on the GOM is taking into account the extra battery.
I've seen this guy before, and I'm pretty sure he's not actually adding up the capacity, he's just switching between BMSes. Also, very scant information for such a big project, and that amount of weight on the rear wheels may seem okay on the photo, but is going to require big coilovers to become manageable. I've driven around with that amount of weight and it's bump stop hell at that point.

Re: Extra Battery, How to Integrate with 24kWh Traction Battery?

Posted: Wed May 02, 2018 8:34 am
by lorenfb
mux wrote: An actual Leaf extender kit that works as if your car simply had a bigger battery doesn't exist yet, right? Like, I'm developing that right now, just making sure that I'm not reinventing the wheel here.
Based on your knowledge and efforts, you potentially could develop a profitable business model for providing extender batteries for Gen 1
Leafs. Given the present low value of those Leafs, the availability of scrapped batteries, and "recovering" some of the Leaf's original range
could be profitable for a business venture on your part.

Re: Extra Battery, How to Integrate with 24kWh Traction Battery?

Posted: Wed May 02, 2018 9:40 am
by mux
I sure hope so, because I'm betting on at least some success in this realm. I've decided over the last few weeks to pivot my business operations in this direction, replacing the consultancy work I've been doing in the past few years. So I'll need to make money doing it.

Re: Extra Battery, How to Integrate with 24kWh Traction Battery?

Posted: Wed May 02, 2018 1:42 pm
by Marktm
mux wrote: I've seen this guy before, and I'm pretty sure he's not actually adding up the capacity, he's just switching between BMSes. Also, very scant information for such a big project, and that amount of weight on the rear wheels may seem okay on the photo, but is going to require big coilovers to become manageable. I've driven around with that amount of weight and it's bump stop hell at that point.
I talked with the Craigslist "seller". He states that he is a degreed electronics engineer from an African Country and works as a night watchman. He has two Leafs. He claims to have removed the battery from one, "chopped it up" to fit in the trunk (my words), routed the high voltage wiring directly through the Leafs vent (breather) to the relocated battery. My best guess from the conversation is that it is a bus to bus connection - two parallel battery packs working with each battery pack BMS (guess work here!). He did this because neither Leaf had the range to go to work and back. Now he does, but seems to have little ideas about what energy capacity he actually has. LeafSpy does not give him proper information, however he does use it to monitor the installed battery cell voltages - and that he uses it to "charge" the two packs. I've got to assume he does not really know the SOC, voltages, temperature of the trunk cells :oops: , but not sure. I may go see it to get more information, as he is quite close.

mux, please PM me to discuss several related issues