need some help i have a 500 budget

[jay7264]

hello everybody i need a ebike setup i cant have a car anymore due to cost and extremely high insurance. my commute to work is 8 miles one way with one road 2miles long and hilly not steep with 2 stretches that are about 1/4 mile inclines the rest is flat. i want to run 48v i also want to be able to peddle it incase of failure or dead battery. will the motor cause rolling resistance when off. im 180 lbs 5'9 is this feasible for 500$ and when im at work i can charge it i asked my boss and he said its ok. i work 8 hrs so plenty of time to charge

 

[MattyCiii]

...i also want to be able to peddle it incase of failure or dead battery...

Look at geared hub motors, they freewheel when not in use and so introduce very little drag.

I used to commute about 8 miles each way by bike alone - no electric assist. Not bad for an out of shape guy over 40. The point is however, let us know how much pedaling you intend to do on a routine basis. The more you pedal, the less powerful setup you'll need, fewer batteries, lower cost... If you don't want to pedal at all, you'll need more battery driving the cost up.

 

[jay7264]

i wanna be able to not peddle at all incase im feeling under the weather or just lazy. i can make the ride but im lazy and only wanna peddle if i have to. like electrical failure/breakdown

 

[dnmun]

i would say it is not feasible unless someone gives you the bike free and the motor and controller and throttle for nothing and the battery used and needing repairs. try pedaling and if it is too much then maybe you can carpool with someone.

 

[jay7264]

Got a lifepo4 from eBay 48volt 10 ah I already got the bike. The battery cost 270. 500 minus 270. I have 230 left I'm gonna save a little more till I have about 350 for a motor

 

[100volts+]

Geared hub means no drag when pedaling. I ride to work everyday and have a dd hub motor but I'm only 3 miles away. I had to walk most of the way home once (flat tire) in two years. That was bad enough.
Try to get good tires. I use Maxxis now and haven't had a flat using them. Start out with a simple, low power system, go for the gusto if you are still into it in a year or so. Not enduring the cost of a car helps you save big time. Plus a low cost front geared hub system on a Walmart Huffy is a chick magnet.

 

[jay7264]

The bike i have is an aluminum giant with disc front and rear. Im wondering if i should scrap the idea of building and just buy my friends evg ebike its already upgraded to lipos from an rc heli and the motor is a magic pie. he said he'll sell it to me for 400$ is it a good bike it doesnt even have disc brakes

 

[Dauntless]

Isn't ready made always nice. Try riding it. Will it really make the trip? Not much we can tell you from a distance.

 

[dogman dan]

That's the kind of deal you needed on the motor, but charging lipo at work is a bit touchy. And EVG frame is a very good starting point, and the pie is a good reliable motor.

Your battery will run the bike with the pie, but you should take it slow and easy or the battery will be considerably strained by the larger motor.

Given a few of the things you said before, you should just allocate up to $400 for a small geared motor and a 10-15 amps controller. That way a larger motor doesn't kill your battery excessively fast.

Or, buy the EVG, but get a 15 ah battery. Perhaps you could get another battery later, and run carefully on the one you have for awhile. Or, maybe get some of your money back from the battery by selling it.

 

[jay7264]

Thanks everybody for the advice. Im so excited about getting it monday. One things for sure i wont miss car insurance registration fees oil changes inspection fees tickets harassment from the fuzz. But i will miss that super charger whine from my toyota solara

 

[dogman dan]

You are getting the EVG? It should be a good setup, but be aware of the fire danger of using lico (RC lipo) packs.

You have a ton to learn, but the first one is, don't park the bike anyplace you wouldn't build a campfire. Hopefully you can just remove the lico battery and store only it in a safer place.

 

[jay7264]

I have experience with lipo lifep04 lion I've been doing rc stuff for years heli and rc car. Only concern I have is the BMS that part I need to learn. My job gets lots of drill battery packs maybe I can do something with them. Makita and ridged lithium packs I might be able to build a 12c 5p pack. Just need to figure out how to balance all of them

 

[wesnewell]

Welcome to ES****Do this before your first post or now (it's retroactive)*****
Please go to the User Control Panel, select Profile, and then enter your city, state/province, and country into the Location field (country minimum) and save it. This will help people help you. Example: Wylie, TX, USA. Without knowing what country you are in it's hard to make any recommendations and you will waste your time and others. Thank you.

The $400 bike sounds like your best deal to me if the bike and battery are in good shape. Sounds below cost to me. 10ah of 12s lipo will get you back and forth to work on a single charge if you don't hot rod it.

 

[dogman dan]

Well, then the EVG gets to looking a lot better for you for sure. You have experience, so you know what's ok and what's not with lico.

I started out with lead, nicads, and lifepo4, but now run only lico because I could replace lico cheaper than I could replace my lifepo4.

No bms, I find the key thing to be to sort the packs and remove any that have cells that don't perform well. Then, by running a conservative dod, I don't unbalance the pack every ride. This allows me to simply monitor whole pack voltage as I ride, with no worries about one cell going into overdischarge. I try to stop when I am at 3.7v per cell or sooner.

The idea is, build a pack that tends to stay balanced, then don't pound it into unbalance. Then no bms works fine. The down side is each 5 ah pack produces only 4 ah you can use, so you have to upsize the whole pack to have good range.

Unless I misunderstand, you already got the 10 ah lifepo4? If you want to, you can parallel some lico with your lifepo4. You can connect 14s lico with a 16s lifepo4, and the voltages are pretty close. It worked for me, when I was squeezing the last bit from my lifepo4 that was too weak to run my bike by itself anymore.

 

[canadianbikeguy]

What does the term "DOD" mean, I have come across that term a few times now.

 

[Ykick]

What does the term "DOD" mean, I have come across that term a few times now.

depth of discharge - is what I think it means and use for that description.

For example if you have a 10Ah battery and consume 5Ah call that 50% DOD.

 

[jay7264]

Well I got the bike its 7 cell lipo 5ah. I totally got burnt on this bike no BMS or anything I'm riding a ticking bomb. I'm so pissed oh well I guess he's not a friend lol I'm gonna cut him off and when the bike catches fire I'm gonna throw it threw his front window

 

[r3volved]

Dead on delivery?

 

[jay7264]

No it rides but no BMS is dangerous and also 5ah isn't gonna get me that far. I have a 8 mile ride to work one way this thing won't make that

 

[maurtis]

No it rides but no BMS is dangerous and also 5ah isn't gonna get me that far. I have a 8 mile ride to work one way this thing won't make that

Unless the guy told you it had a BMS, I do not think he was trying to screw you. Like Dogman said, he does not run a BMS with lipo, neither do I on my two lipo ebikes. I do keep an eye on the pack charge while riding (simple volt gauge on one, CA on the other) and use a cell checker to monitor the individual cells before and after a ride, and balance charge every now and then...

Lipo takes a good bit of care, but not a ticking time bomb if you keep an eye on them. But I would definitely go with more than 5ah, though.

Btw, is that using a single 7s 5ah brick? 7s seems really low for a Magic Pie. 14s and 15ah sounds more like it...

 

[jay7264]

From what I've been seeing and reading its not a magic pie motor I got had. It will run with light peddling about 17 mph. Its a 24 volt controller I was thinking to get a 36 volt controller and using makita packs or dewalt packs. Its only a 250 watt motor geared brushless hub. I kept an eye on tempeture of the motor and it doesn't even get warm on the pack now. Would I be safe to run 36 volts to it to get that extra umphh? I don't wanna blow it up though. I'm a conservative rider I just want about 20-22 mph.

 

[heavymetalthunder]

Using Lipos require a special charger. For the distance you plan to travel, I recommend 4 5000 mah 6s lipos 20c or better. I commute on a cargo bike 11 miles to work and I usually ride with the flow of traffic in the slow lane (30 + MPH). I use a combo of 4 cell and 6 cell batteries giving me the power of 8 5000mah lipos, at that speed the bike is a power hog 1200 watts of power draw. Arriving at work I use about 65% of my battery power. My tests have shown the best combo of speed and pedaling is at about 15 to 17 mph using about 260 watts of power. Pedaling can give you about 120 watts of power.

 

[dogman dan]

Hmm, well you did get ripped some. I would call that basic EVG frame worth $200. It really can be a superb frame for an ebike. The motor kit, used, worth $100. That battery also was worth $100. So maybe only taken for about $50.

It's yours now. So YOUR FAULT, if you let the batteries burn it.

Do some checking on the batteries. Find out if any have a single cell in them that is a lot lower than the others when you have discharged them to 3.5-3.65v per cell. Around 24 -25 v total pack voltage,

5 ah won't be much, but the motor is weak so you will get a lot out of a small pack like that.

One last time. Did you buy a lifepo4? I can't tell from the way you talk, if you did something or just thought about it. If you didn't buy that battery, you have $100 in your budget to buy some more lipo, and some tools to monitor it.

What did you get for charging in that deal, anything?

You have 7s battery now. It's very plausible that your controller can take more voltage, increasing your speed a bit. We can talk about that more later.

 

[maurtis]

I guess pictures would help...

He told you it was a Magic Pie and it turns out to be a bitty little 250W geared hub? That is a huge difference. If the guy did indeed misrepresent the bike, he is no friend and quite an a-hole.

The good news is that the EVG is a fine frame to build off of, and I would think the 250W geared hub motor should take you to 20 MPH without issue with a little more voltage. Still, sorry for the douchery

 

[jay7264]

No I canceled the order for the lifep04. And the 7 cell pack is healthy 4.1 across the board. But the 5ah is a friggin joke he skimped on power big time. Like I said he is no longer my friend I already told him he ripped me off. I was thinking to do 36 volt and change my controller to get some more speed and distance out of it that's all. My goal is 20 miles and 20-22 mph. I'm gonna buy a 36 volt lifep04 soon or build one out of 18650 cells