9 miles, 320 lb guy, 20 mph, flat, winter

[wesnewell]

The dangers of rc lipo is greatly overstated by people. I own my home. I hate insurance, so I don't have any insurance on it. If I thought I would burn my house down using rc lipo, I wouldn't use it. But, i also don't throw 9V batteries in a drawer with steel wool. Any idiot can start a fire with a 9V battery, or any other battery. Starting a fire with rc lipo isn't as easy as people make out. I'd worry more about 18650 cell packs. They don't puff up, they just ignite without much warning, as seen in many news stories over the last year or so. And even though most are weak as crap, you see people here pushing them to noobs all the time as being safer. Before you make up your mind, read this;
https://endless-sphere.com/forums/viewtopic.php?f=14&t=27241

 

[David LaFerney]

I'm new to this also, and don't want a fire either - But I can't always be there while batteries are charging. On top of trying to do it in a safe location, I put the batteries inside of a "fat 50" mil surplus ammo box (with a small hole for the charge leads to go through) and I bought a yard of kevlar to use as an inner wrap on the battery packs. I don't know if that will contain a battery fire or not, but it couldn't hurt. When not charging the charger and associated kit stores in the ammo case.

 

[David LaFerney]

Thanks for all the further advice. Won't it be a surprise the first time I stumble into the shower half-asleep and forget there is 420 W-h waiting to jump through my toes!

you'll severely harm the life of the battery charging/using it while cold.

So, I feel like this renders the whole project moot. Im not going to bring the pack into the office, so it has to sit in the cold all day. I don't think I'm willing to eat the cost, but would LiFePO4 be pretty much 100 percent safe in the office?

There's a guy on YouTube - ElectricBike - who apparently has several bikes but only one battery pack with a long lead that he wears in a backpack. If you did that you could surely bring a backpack into work with you to keep it safe and warm, and a quick 5 mile commute wouldn't be long enough for it to get cold enough to hurt it. If you are worried about it at all you could wrap it up in an insulated bag. Which would also protect if in case of a spill - which could also prevent a fire. It's also a great solution to the question of where and how to mount the battery.

 

[docw009]

Unattended charging. Here's a guy who knows better, but he stepped away for 10 minutes. Boom. He lost his store. Point being that even people in the RC business sometimes get a little careless, and it bites them.

http://thedronegirl.com/2015/01/29/lipo-battery-may-have-caused-rc-shop-fire/

 

[mailseth]

I'm browsing through the battery fires summary thread:
https://endless-sphere.com/forums/viewtopic.php?f=14&t=69721

There's a lot of snow in the background, and a lot of lipos. Keep your batteries warm (above freezing), and don't use lipos. Also, don't cheap out on batteries.

 

[keninct]

Alrighty then, kids, I think we're back to what was my plan A before I arrived at endless-sphere: the lightweight winter hack motorcycle option. I learned an absolute ton from this thread and I'd like to thank everyone who contributed.

I'll be back to the sphere for sure as soon as I can afford a Zero DS!

 

[mailseth]

I'd be all for getting an ebike for commuting, but I think it's a case of "Buy nice or buy twice" (with the added benefit of fire.) With the threshold for "nice", in this case, being something where the battery is worth approximately keninct's entire budget.

 

[MadRhino]

Building for a big guy who will commute in all weather with 400$ budget is somewhat utopic. Not that it can't be done, but not very realistic for someone who doesn't have building skills. Anyway, you might bust your budget, but you will not regret.

I agree that RC Lipo should never left charging unattended. That is number one rule with aggressive chemistry. Even if you have a place where they could not set fire to anything, you don't want to fume your home or neighbourhood with lipo smoke. When you are with them, they will not start a fire for they start to puff and smell before and you have plenty of time to unplug. RC Lipo is used by those who are building high power, because it can deliver a lot and can be charged quickly. Using aggressive chemistry because it is cheap is not a very good reason, simply because on the long term it is not cheap. It does fail quickly sometimes, and sometimes it arrives with bad cells, and sometimes someone set them in fire. On the long term, more stable chemistries are a much better choice when you don't need the power. It is pretty much like you would not run a lawnmower with Top Fuel Nitromethane unless you are a gambler and don't give a sh*t about when it will fail.

 

[drew12345]

Sorry, I would not recommend a noob use lipo. It's too dangerous.

 

[wesnewell]

Sorry, I would not recommend a noob use lipo. It's too dangerous.

roflmao. There's 6 year old kids that have used it safely for years. It's only as dangerous as the user. After everyone here tried to talk me into lifepo4 in 2011, I went with rc lipo and have never regretted it. Been running a 10ah 24s pack for over 4 years now. Started with 14s, quickly went to 18s for about a year. Still nothing better for ebike use imo. Have recently been testing my old rc lipo in UPS's. 7s packs work great in 24V ups systems. I plan to switch all of them to rc lipo packs as the crappy sla batteries die.

 

[teklektik]

...there have also been many cases where lithium batteries appear to have caught fire for absolutely no reason, when sitting idle not being charged, discharged, or subject to any external forces. I've been party to 2 instances of this happening firsthand, once in someone's bedroom room here in Vancouver ..., and in another case one of our suppliers had a battery inside a pallet in their warehouse just go into spontaneous combustion. Both of these situations were with ebike grade ~10Ah LiPo cells.

So yes, sitting there, not charging, not discharging, not visibly doing anything, lithium packs can and have gone catastrophic, and if you're in this industry long enough it will come alarming close and personal, not just anecdotal. That's why I get a bit annoyed to see so many people on ES immediately jump to the safety defense of lithium (especially lipo) batteries and claim issues are always the result of user error. Just because you yourself haven't so far had any problems with your giant collection of hobby packs and carefully balance and baby them, doesn't mean that you'll always be so lucky.

My own feeling on the relative safety with 18650 packs is that's it's probably better than most consumer plug-in appliances at this stage.

 

[Chalo]

The problem is I can't seem to get the cost down to a point I can justify to myself for what is, essentially, a lark. I think if I could get the whole deal below $400 I would definitely go for it.

Getting to and from work every day is "a lark" for you? How much do you spend on it already?

My girlfriend was just telling me that she thought $1200 was too much to spend for a bike. What that tells me is only that she never does anything with her bike that's worth $1200. But she just a few days ago spent $1900 getting her car fixed.

If you live less than 5 miles from work, you've already made the primary lifestyle choice that enables you to use a bicycle for transportation. So why don't you give yourself a fighting chance to succeed by treating it as real transportation, rather than a lark?

 

[MadRhino]

...there have also been many cases where lithium batteries appear to have caught fire for absolutely no reason, when sitting idle not being charged, discharged, or subject to any external forces. I've been party to 2 instances of this happening firsthand, once in someone's bedroom room here in Vancouver ..., and in another case one of our suppliers had a battery inside a pallet in their warehouse just go into spontaneous combustion. Both of these situations were with ebike grade ~10Ah LiPo cells.

So yes, sitting there, not charging, not discharging, not visibly doing anything, lithium packs can and have gone catastrophic, and if you're in this industry long enough it will come alarming close and personal, not just anecdotal. That's why I get a bit annoyed to see so many people on ES immediately jump to the safety defense of lithium (especially lipo) batteries and claim issues are always the result of user error. Just because you yourself haven't so far had any problems with your giant collection of hobby packs and carefully balance and baby them, doesn't mean that you'll always be so lucky.

My own feeling on the relative safety with 18650 packs is that's it's probably better than most consumer plug-in appliances at this stage.

I can testify of the same. I have had a new brick of high C rate RC Lipo that had a small short in the balance wiring and was leaking gas. I was bothered by the smell in the garage and inspected all the bricks that I had, to find this one that was a fire waiting to happen. Never trust RC Lipo, always treat them like what they are: Unstable chemistry that can catch fire with the sole contact with air. A thin layer of plastic (maybe sealed by a Chinese kid) is the only barrier that is keeping LiCo pouch cells from catching fire.

We use it because there is no equivalent for performance, like industry is using many other dangerous products to achieve production requirements. I never recommend using a dangerous chemistry for the only reason that it is cheap. When I tell someone that it is a solution for his target performance, it is always with detailed warnings.

 

[keninct]

The cost analysis is really specific to me and not a reflection on ebikes in general. I'm not desperate for a way to get to work. I normally ride a motorcycle (V-Strom 650 if anyone cares). In past winters my wife has driven me either a half mile to a busway that zips right to the office, or all 5 miles into the office. So this whole thing is just about my love of riding and a desire to bring a little adventure into my otherwise banal workaday life. I decided I didn't want to put the 'Strom through winter abuse, so my options are to either get another bike for winter or to try the ebike idea.

All things being equal, I'd rather own another motorcycle! In particular, I'd like to replace a small dual sport I had stolen last year, a Yamaha XT225, and use that for the winter commuting adventure. So when the cost starts to climb up to $600, $700, or more, we're talking about a big chunk of doing that. Or when the inconvenience starts to go much beyond the already significant PITA of bundling and armoring up -- like attending to a battery charger for hours every day -- well, that pretty much means I'm out, too.

But I really love the EV concept in so many ways: green, low-maintenance, high-torque, etc., so I definitely want to get on board at some point. And I have to say, other than some challenges reaching consensus on risk management, your community here at E-S seems amazing, and I'm glad I asked my questions here and met you guys. Thanks again!!!

 

[MadRhino]

The cost analysis is really specific to me and not a reflection on ebikes in general. I'm not desperate for a way to get to work. I normally ride a motorcycle (V-Strom 650 if anyone cares). In past winters...

It is a misconception of ebikes, from someone who rides a gasser. 600$ is ridiculous if you compare with all the expanses that you put into a motorcycle. I build ebikes that are 10 to 15 times that amount, and both my gassers are rotting in a garage for years.

Gess why ? I have better performance and handling, in silence and for a cheaper cost. Plus, I have freedom, for I can benefit of all the privileges of a bicycle with the power of a motorcycle. I need no license plates nor driver license, I can ride the parks, park on the sidewalk... Lift my bike on my shoulder and climb it in a ladder if I'd need to.
I charge under strict supervision, 5 to 7 minutes, not even long enough to smoke a cigarette. Maintenance is cheap and quick, mostly changing brake pads and tires. 600$ is what I just paid for a new motor after 20K miles, because I neglected to replace a bearing, otherwise it could have lasted 50K.

Powerful ebikes are few, but they have a bright future. Now we are in a parallel world: Illegal ultra lightweight motorcycles that have a free pass because they have pedals and make no noise. Friends on motorcycles who are trying to catch with me in town, end up with tickets and police hassle while I ride away like the invisible man.

Gas is over for me, and it should for a growing number of motorists. My advice is: Spend the 600$, Enjoy the freedom and economy it gives you. I predict that you will build a much more powerful bike soon, and forget your gassers like I did.

 

[spinningmagnets]

I still have my 4-cyclinder truck, but...by moving within 8 miles from my work, I can now easily get to work on my electric bike. You can get a very reliable and good-performing ebike kit for $1500, but if you decided to get a spare used car, $1500 will not get you much, and you have to find a place to park it, plus pay insurance.

My hats off to those intrepid ebikers who have no car and have gone for a completely "car-free" lifestyle. I will keep my truck...

 

[Chalo]

My hats off to those intrepid ebikers who have no car and have gone for a completely "car-free" lifestyle. I will keep my truck...

Better yet is to depend on a pedal bike (which is more dependable and self-sufficient), but keep an e-bike for fun and convenience.

 

[keninct]

Haha not saying I couldn't use the exercise. I still have the garment pannier from when I pedaled to work a few years back. But it takes a lot of motivation to do everything from packing to showering and dressing at the office.

I know I said I was done with this idea, but someone made a pretty inspired pitch for going big instead of going home, and I am actually thinking about it. I need to read more about recharging in 7 minutes, I didn't know that was a possibility.

 

[mailseth]

The great thing about an eBike is you won't need to shower at the office. Depending on the office, you may not need to change, either. Personally, the minimum I'd look for is a Sondors ($700 shipped) due to the fat tires on snow & the enclosure for the battery/controller. The controller would be able to keep the battery warmer while you're using it, and the battery is removable so you can bring it into the house/office. (And the battery isn't something hacked together from RC packs.) The upgraded battery should give you 9 miles easy, especially if it's flat.

Once you've spent some time on that, you'll catch the ebike bug and want to upgrade it and/or you'll wish that you bought a higher-end bike. (But not because the Sondors isn't capable or has burnt your house down.)

 

[spinningmagnets]

My hats off to those intrepid ebikers who have no car and have gone for a completely "car-free" lifestyle. I will keep my truck...

Better yet is to depend on a pedal bike (which is more dependable and self-sufficient), but keep an e-bike for fun and convenience

I have three bicycles right now. A mid drive, a rear hubmotor, and a pedal-bike with no motor...plus the aforementioned 4-cylinder Toyota from 1991 that refuses to die...

 

[mailseth]

I was browsing this article and was reminded of this thread:
http://batteryuniversity.com/learn/article/charging_at_high_and_low_temperatures

Li ion batteries offer reasonably good charging performance at cooler temperatures and allow fast-charging in a temperature bandwidth of 5 to 45°C (41 to 113°F). Below 5°C, the charge current should be reduced, and no charging is permitted at freezing temperatures. During charge, the internal cell resistance causes a slight temperature rise that compensates for some of the cold. The internal resistance of all batteries rises when cold.

Many battery users are unaware that consumer-grade lithium-ion batteries cannot be charged below 0°C (32°F). Although the pack appears to be charging normally, plating of metallic lithium can occur on the anode during a sub-freezing charge. This is permanent and cannot be removed with cycling. Batteries with lithium plating are more vulnerable to failure if exposed to vibration or other stressful conditions. Advanced chargers (Cadex) prevent charging Li-ion below freezing.