battery recommendations for a motorcycle?

spectastic

1 mW
Joined
Jul 24, 2017
Messages
18
for a few days now, i've been thinking about an electric motorcycle.

nissan leaf modules seem to be a popular choice, but by now, they're considered old tech. the better batteries now use NCM and NCA chemistry, but my understanding is that they also tend to be a little expensive. my interest isn't with the energy density of the batteries so much as the electrolytes additives that companies are adding these days that boost cycle life to upwards of 1000s of cycles, which is a huge improvement from 2010-2011, around when the first nissan leafs came out. i assume that these 2p2s nissan leaf modules come from the same time period, and nissan is apparently phasing out these modules in favor of NCM chemistries for their future productions

18650 is another option, but it would involve a lot of spot welding and a lot more work, compared to having larger packs that can stack nicely against each other, and be easier to work with. perhaps some people sell 72V 18650 packs that can be used. that would take away a lot of the leg work on my part.

but that's the extent of my knowledge as far as what options are out there. are there good recommendations for cost effective, easy to work with battery packs that also use somewhat modern chemistry, or am I dreaming?

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https://electrek.co/2017/05/04/tesla-battery-researcher-chemistry-lifcycle/

this is what i mean when it comes to electrolyte additives. jeff dahn is the real deal. look at that man.. they're tripling the cycle life of these batteries with that secret sauce.
 
My opinion is that if you design and specify your cells well, you'll get at decent life from even cheap cells. If you use the Leaf cells, as intended - in a 80-20% DoD, and low C rates in and out, kept cool, you'll get the 8-10 year life out of them, that the Leaf was meant to get. If you leave them fully charged most the time, take off every light at full throttle, and leave your bike parked in the sun with no cooling, they'll wear down fast.

The closest thing to a "magic bullet" you'll find is probably Lithium Titanate Oxide. 25k cycles, 30 year shelf life, can be discharged flat, tolerates overcharging, operates to -40*C, and can experience extended +40*C temps without any loss of capacity or power density.

I'm building a huge pack of them now.

However, their energy density sucks. I'm pulling out 40AH of LiFePo4 cells to put 28AH in. That said, If the 25Ah cells were still in production, I could have fit 50Ah in.

If LTO is not your thing, get whatever represents bang for buck for you, but build it oversize. Then set your charger and BMS to cut charging at 3.93v. This will virtually eliminate all high voltage wearing.

Make sure that the peak draw of the motorcycle never gets the pack warm. In RC lipo, this usually means about 1/4 of the official rating. Not sure what that is for Leaf.

Charge as often as you can. You can often get 8-10x the number of cycles by only using half the available power. So even if it's inconvenient, charge at work and at home.

It seems like a lot of people really want to get 1000s of cycles out of their batteries. That's very understandable if you're paying $100k for a Tesla, or $30k for a Leaf, but if you're forking out $500 for a DIY motorcycle, I can almost guarantee that by the time the battery needs replacing, there'll be a newer battery chemistry you'll want anyway and use it to justify your aging battery.
 
You want Leaf cells manufactured between April of 2013 (earlier 2013 builds have the bad early chemistry) and whenever in 2015 they stopped making 24kwh packs. 2015 "Lizard" cells are the absolute best Nissan ever made. You want to avoid both the pre-4/2013 cells AND the 30kwh pack cells made in 2016 & 2017 - they degrade so fast you might end up worse off than if you used 24kwh pack cells. I've been following this since the early cells were proven inferior in 2015. (I also drive a 40kwh 2018 Leaf, with fingers crossed and the car kept as cool as possible!)

Oh, and I ride a Vectrix with Leaf cells that were likely made in early 2013. I keep that bike even cooler...
 
I built 2 packs from 2016 Leaf cells, both 11S.
cells from wrecked 2016 Leaf , that is what HybridAuto Centre says, but what is real history of this pack and how it was used nobody know.
"I still have some juce left..." attitude is rather widespread in NAmerica.
There is no way to buy brand new EV battery from wherever.
 
cool thanks for the tips.

how do you keep the batteries cool during charging and/or under the sun? I figure keep it under a cover when it's in the driveway (no garage :'(). Is a fan really necessary?

i think for the setup that i'm imagining, with a ~9 kWh system (I think/hope my bike can fit that many modules), with a 550 amp motor, the maximum draw I'll get out of that is ~5c, but that's only if i accelerate to go on the highway probably. and I'm not sure the controller would even allow 550 amps. the main thing I'm after is low end torque of accelerating out of intersections, and the current draw coming out of 0 mph is relatively small. the top speed is what requires a lot of hp and amps, but that isn't very critical to me.
 
Chevy Volt batteries and the 25ah Panasonic cells used by Ford and other blow away the saggy Nissan Leaf modules by a wide margin.
 
spectastic said:
cool thanks for the tips.

how do you keep the batteries cool during charging and/or under the sun? I figure keep it under a cover when it's in the driveway (no garage :'(). Is a fan really necessary?

i think for the setup that i'm imagining, with a ~9 kWh system (I think/hope my bike can fit that many modules), with a 550 amp motor, the maximum draw I'll get out of that is ~5c, but that's only if i accelerate to go on the highway probably. and I'm not sure the controller would even allow 550 amps. the main thing I'm after is low end torque of accelerating out of intersections, and the current draw coming out of 0 mph is relatively small. the top speed is what requires a lot of hp and amps, but that isn't very critical to me.

Charge late at night/early morning when the pack is coolest, and try your best to avoid charging in the heat of the day. Put a temp sensor or three on the surface of the pack, and add several degrees to that reading for internal temp. Try to avoid charging when the internal temp is above 80F, or about 78F on the surface. I have a usually-cool garage, which helps a lot. Do use a fan, but remember: if the air is hot, then you aren't cooling the pack. A used portable A/C unit to cool the pack while charging might be a good investment if you live in a hot climate.
 
I have built 4S start up battery from 41Ah Nissan Leaf cells for my V-6 Honda
how harsh and brutal is environment under the hood of gasoline car I don't have to tell you.
from at the very minimum plus 40C when engine runs on hot day to minus 30C - brutal indeed
Nissan cells show perfectly balanced , survived 2 winter .
 
John in CR said:
Chevy Volt batteries and the 25ah Panasonic cells used by Ford and other blow away the saggy Nissan Leaf modules by a wide margin.

are you referring to these?
http://edisonmotors.net/shop/product/panasonic-25ah-nmc-3-7v-battery-cell-25ah-218?category=7

their $/Wh is almost twice that of the nissan leaf modules though ($0.43/Wh vs $0.24/Wh)

leaf modules: http://hybridautocenter.com/HAC4/index.php?option=com_hikashop&ctrl=product&task=show&cid=91&name=58ah-nissan-leaf-battery-module&Itemid=605
 
spectatic
link you provide from Hybrid Auto Centre shows old type of Leaf modules - 31Ah per cell, 4 cells per module.
New Leaf battery uses 8 cells per module
besides, you dont compare brand new Panasonc to used Leaf cells?
 
you would have to provide discharge tests but
I dont think Panasonic sags so much less than Leaf.
I run A123 20 Ah and Leaf 41Ah and Leaf cell provide solid 35Ah at 20A discharge.
 
I only buy used car batteries now, so I never pay even 20cents/wh. I used a big car battery tester to do 100A, 200A and 300A with 4s packs at a 3.8V/cell SOC (single cell 25ah Panasonics from a Ford (I assume Panasonics since the guy selling them for $22/ea on the forum calls them Panasonics), 44ah Chevy Volt (3p cells), and 66ah Leaf modules) short discharges and compared the voltages under load, and the 66ah Leaf modules sagged enough more than the others that I didn't even hit it with 300A. The Panasonics sagged slightly less than the Volts. Plus LFP told me those Leaf cells were the same Chemistry as the Konions I was so accustomed, sure nice and safe with a tendency toward self balancing due to increased internal resistance nearing top of charge, but sag city. While my testing wasn't scientific, it was good enough to convince me.

One good thing about the Panasonics that the other don't have is that if over-charged to puffing, the bus bars cause the terminals to shear off, reducing the possibility of creating a short. I discovered this aspect when a charger failed and killed a 10s string by over-charging them.

Other pluses include the ease of getting any voltage by bolting the single cells together in series along with the smallest width and height dimensions of the three. I've been hitting a 1p string for over a year with twice a day 50% DOD discharge at 150A peack and I've seen zero reduction in capacity (my end of commute voltage is so consistent that I see variances based on wind direction and strength after accounting for how hard I ride, so I believe Ford's 10yr battery warranty is low risk to them.

Regardless of choice, unless price is no object, automotive batteries are the way to go in terms of price and engineering for safety. I ran RC lipo for years, and their short life makes them quite expensive, but the real cost that would prevent me from even considering using them in a motorcycle size pack is the comparatively high fire risk.
 
running discharge tests on USED whatever cells from two different EV/Hybrids makes little sense to me.
you simply dont know history of this cells
hoever sell them , should you trust their words?
typically salvage yards sell used packs, citing only year of car, maybe millage which is impossible to verify.
you see what I mean?
One pack in given Hybrid/EV was owned by electrical guy, never fully discharged , used 50% SOC in only short trips , in mild NOT HOT climate.
Another pack in given Hybrid/Ev was fully discharged many times , used in HOT CLIMATE
unless you compare brand new packs and cells ...
 
Go ahead and buy Leaf modules, because it means less competition for the better stuff. I didn't even need to bother with testing after LFP told me about them. I shared the info I found in interesting. BTW I only buy low mileage stuff, and the Leaf module rack I bought was from a wrecked with under 1k miles car. AFAIC used batts are better than new if you get entire racks that are still in perfect balance...no worries about bad cells...the initial step down in capacity is already out of the way which I confirm by full discharge test of a single sell.
 
maybe i just suck at googling, but it looks a lot of the leaf modules are out of stock in the online retailers. how do you buy used car batteries, especially if you want to make sure they're good?

also, they did a study comparing the newer nissan leaf batteries with the first gen batteries. the new batteries don't last as long as the old ones apparently. the increased capacity comes at a cost. one other thing they apparently did was getting rid of the ability for the cars to stop charging at 80% SOC, and that could have contributed to the faster deterioration. go figure.
 
I would run RC lipo. Best discharge curve, best C rating, quick charge capacity unrivaled by anything else (5C is common) and easy custom pack builds. There are 2 downsides to this: one is cost and two RC lipo although power dense is not very energy dense compared to good 18650.
 
history of usage of EV has big influence on longevity of pack and cells and on condition of pack, means condition of cells.
one must be careful in comparing 2 cells from two different EV packs
provide, please
any link to specs of Chevy Volt packs /cells, what cells exactely Volt is using????
are they /Volt cells/ at very least the same capacity - for sure not.
so comparing apples to oranges already.
big unknown!!
Even HybridAutoCentre who sell Volt modules does not know exactely.
I doubt Volt cells are so much less saggy.
 
for a few days now, i've been thinking about an electric motorcycle.

So. Just to clarify... a two-wheeled bettery-electric powered vehicle capable of "stupid"/"outrageous" speeds for "short distance"/"urban" travels at "slow" speeds ("stuck" in urban, "congested" traffic), correct?
 
Never thought "spectastic" WAS drinking... just hasn't come up with THEIR definition of "motorcycle". Like, with a body shell like a velomobile?
 
fuel1.jpg
 
If I was building a motorcycle conversion, I'd look for Chevy Volt cells. A hybrid battery pack is much smaller than a pure EV pack, but it has to provide full system amps. This means they are high-amp cells.

This might raise the question as to why full EV battery packs don't use high-amp cells, and the answer is this...if the factory-designed pack is large enough to provide more than enough amps, then...use the cells that have the greatest capacity (range in miles).

My second choice would be an entire pack from a wrecked Zero E-moto, but...they are rare. There are simply more Chevy Volt packs on Ebay than any other type of high-amp cell.

"Salvaged EV cells index, Leaf, Volt, Tesla, etc"
https://endless-sphere.com/forums/viewtopic.php?f=14&t=89680
 
I'm using A123 cells on my motorbike right now. 23S and2P, so about 76V/40Ah.
They are quite impressive, I made quite a lot of test so far:
-I get about 75-80km of range at relatively aggressive speeds
-Voltage sag is about 2.5V while drawing 210Amps from the battery (a bit more than 5C)
-They really don't heat much
-The cells stay very much in balance
-Capacity seems to be almost unaffected by current draw, you can ride it hard and it doesn't seem like you lose much range at all.

I had other lithium batteries in the past and so far this one seems perfect to me.
I only wish is was a bit more power dense, but 80km is already enough range for me right now, and I have enough space to add another one of those battery packs so I could easily do 160km if I ever feel the need. Well anyways, you can go for it, it will work great on whatever motorbike you're planning.

You can check my build thread if you want, it might give you some ideas :)
https://endless-sphere.com/forums/viewtopic.php?f=12&t=90032

Good luck with your build!
 
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