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[Richard230]

Getting back to Zero battery life for a moment, I keep having an issue with the recommendation for storing Li batteries at around 70% of their capacity and not keeping the bike plugged in all the time with regards to a daily rider.  I keep my bike plugged in all the time as Zero recommends.  If I didn't do that it would not have the range that I might need during a ride. 

I can see storing a pile of loose batteries partially discharged, but when installed in a vehicle there is probably some parasitic drain from the BMS that would eventually brick the batteries if the charger was not connected regularly (that is what happened to my GPR-S when it was stored for 2 months without being recharged).

So I can't see any disadvantage to following Zero's recommendation of keeping the charger plugged in 24/7, especially if you ride the bike almost every day as I do. 

Maybe if you are storing the bike during the winter you might want to hook up a timer that would turn on the charger once a week, but I am not sure that would be much different than keeping it connected all the time as, when turned on, the charger would recharge the batteries to full capacity again.  So it still seems to me that leaving the bike's charger hooked up all the time is the only practical way of making sure that the batteries remain in good condition, even during long term storage - short of disconnecting the entire pack from the bike's electronic monitoring system.

[trikester]

The only time I unplug my Zero bikes is during a thunderstorm when I'm concerned that a strike on the line near the house would blow the electronics. I have surge arrestors on AC outlets but I don't count on those for a powerful strike near the house. At my desert cabin a strike on a power pole on my property wiped out about $600 worth of equipment. That strike shattered the cross-arm  and burned a "crater" in the top of the pole. Anything connected to the AC line, and grounded, in my buildings got creamed. Even one of the GFI outlets was destroyed! Any and every path to ground was taken by the current from that strike.

Otherwise my bikes stay plugged in as Zero says.

Trikester

[dkw12002]

I ride my Zero every day it isn't raining too, year around. The first issue I ran across with keeping the bike plugged in all the time was the warning I got when I plugged in the bike just after a ride. I think the battery was too hot, but that's just a guess. Once I cooled off the battery with the fan, it took the charge, so there's that issue this time of year. Then the idea of charging a nearly full battery which may not be good for it, and thirdly, I also got a warning light...possibly warm battery again, but not sure, when I plugged in the Zero after a pretty long ride with both motor and battery pretty hot, then interrupted the charge cause I needed the bike again. This resulted in a system light warning that stayed on for quite a while until I think the battery cooled down some more, so what I have been doing after long rides is cool everything down before plugging in the battery. I do this for an hour or more. I tell you this Texas heat is brutal on equipment, ice bikes included. So at 5 am, I head over to the gym and return at 6...2 miles. I don't plug it in. Then at 9, I rode over to exchange a modem...4 miles. Then I went to lunch at Subway 2 miles. The bike has used 1 bar and is not plugged in yet. I will usually go out again 2 more times....one about 3:30 for 2 miles, then an evening ride of 10 miles. Then I cool the bike down with fans for an hour and plug it back in at 8 pm, until 5 am....Usually I've used 2, maybe 3 bars. I may go back to plugging the bike in after each ride once the temp drops a few degrees.

[Lipo423]

I recall talking about the "cooling down" before charging in another thread. Good thing to do...keep it that way (if you want to maintain your batteries in good health)
In 5 years our batteries obsolete? I believe this is a very strong statement (unless obsolete meaning is related with SOC drop because of age). I would not expect HUGE changes in Lithium battery technology in the next 5 years (leaving aside laboratory or prototype-level new chemistries -some of the guys already mentioned a couple of them-), I would expect some improvements in Kw/h-Kg and C charging rate -eventually-
Long-term storaging for Lithium is actually recommended at around 30%, not 70%
I would definitely avoid leaving the bike plugged for long time (whatever Zero says in the owners manual, as they just try to avoid the charger not able to "recover" a low-voltage, or dramatically de-charged pack)

I would bet the horizon is probably 10-15 years (for smaller, fast-charging, and more powerful batteries)

[Richard230]

I agree with Lipo423 regarding future battery tech.  Even if a good practical high-performance battery technology comes along it will take a while for the Chinese to create the infrastructure and factories necessary to start producing the batteries in volume for the consumer market and the first ones on the market are likely to be very expensive and their performance and durability in the field will take a while to be sorted out.

Regarding the battery/motor heating issue, I have yet to have any problem charging the batteries of my 20012 S immediately after a ride and I have never seen any warning lights, other than the side stand-down warning, since buying the bike over 18 months and 6,000 miles ago.  But then I don't live in Texas.   

[Lipo423]

Thanks Richard. You are spot on on the new battery-technology "path"
Concerning the high temperature, I would say there are a number of different factors that could influence that (road-shape, riding stile, weather, etc...), in any case all of our battery packs should get either a little warm, hot, or very hot because the current demand is pretty high (in the first scenario is not a big deal although I still would recommend cooling -you actually get some energy back to the pack due to fact that they get warm ), in the second and third ones, cooling should be mandatory for the battery pack long-term life.
(do not wait for the bike high-temp. protection system)

This is of course my experience...

[Richard230]

I found it interesting that, although Brammo water-cooled the motor of the Empulse, they did not also water cool their battery pack (since they already had a cooling system on the bike).  I assume they did not do so because it was both expensive, complicated and tough to do without also making the battery pack larger and more difficult to build and service.  On the other hand, I can't recall anyone on the Brammo forum complaining about battery overheating issues.  Perhaps the way their batteries are built and mounted makes them easier to cool with the ambient air.  (I seem to recall some discussion that during the winter the batteries can get too cold and that can present problems when charging.)

[Lipo423]

Yep, both "extremes of the line" are bad.
So far, Li-Mn is probably the best overall available chemistry in the market (including working temperature bandwidth). By chance, the one in our 2012 bikes 

Tesla Roadster was one of the first electric cars in adopting a very complex battery pack water cooled system (as far as I know the engineering team had some "interesting" experiences frying quite a few 18650 cells). I rode one a few times (including having a technical issues with the batteries ). Current consumption goes up to 700A 
I remember switching the car off and having the radiator fans on for quite a while.

Temperature management is one of the biggest challenges for designers when building long life battery packs for high-current applications.

[protomech]

I found it interesting that, although Brammo water-cooled the motor of the Empulse, they did not also water cool their battery pack (since they already had a cooling system on the bike).  I assume they did not do so because it was both expensive, complicated and tough to do without also making the battery pack larger and more difficult to build and service.

The Empulse battery pack is passively cooled - each module has cooling fins that do a pretty decent job of cooling the cells. In fact, they work too well in the winter.

The Empulse RR battery pack is subjected to MUCH higher loads (for shorter periods); they force air through the battery pack, but even then it apparently doesn't need liquid cooling. (Or perhaps durability simply isn't a concern, since the battery packs are torn down and rebuilt every year or two)

[NoiseBoy]

That is fairly serious issue on the Brammo.  43F is 6C, I rode for about 2 months every day on the Zero with temperatures at or below 6C and it never skipped a beat.

I think the Ski jacket is a bit excessive too!