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Newbie with an ebike

Posted: Oct 02 2017 6:04pm
by VWhite
Hey there everybody, I've been surfing around this forum for a while now and found a lot of great information and am truly thankful for this wealth of knowledge ill probably never understand. I'm 27 years old living in Florida and to my research there's not very much limiting me in the law from building a sweet ebike, just the financial limit. I have several motorcycles so two wheels is nothing new to me but the electric motor is way past my understanding.

Anyways, due to my own negligence I no longer have a license and ordered some stuff off the internet to hook up to my bicycle to give me any easier ride to work and the store and such. I ordered a 1000w rear hub motor kit that came with controller, brake cut offs, lcd display, twist throttle, pas and all that jazz also ordered what said a 48v 14ah battery (accidentally ordered two).

Now I love the setup, although I do want to customize it to look a little nicer and handle better, currently have the battery on a rear rack. It gets me where I need but I would love a little more range and this is where my question comes in.

On the streets I ride I have no problem getting up to 25mph (or so the display says, haven't double checked it to make sure it's correct) and feel pretty safe doing so. My trip to work is only 5 miles there and 5 miles back but several times through out the week I do need to go off route and end up with about 20-25 miles round trip. I've done 20 miles in one day on a full charge (ripped it up on the way to work in the morning thinking I brought my charger with me but didn't) but felt the need to pedal a good bit on the way home and just use the motor on the hills and to make my input a little easier. I know it would have helped if I didn't goose it in the morning and all, but basically I'm looking for a little more range.

I bought all my stuff pre made in kits because I'm not very knowledgeable about electronics and wanted it to just plug in and go. Now that I have it and feel a little more comfortable since finding this forum I feel that I'm ready to start tinkering and getting it just like I want it.

Since I bought two of the same battery I'm assuming I could run them in parallel to just "double" my range. But I don't really want all that weight if I really don't need "double". I took my battery apart(kinda) to see how much room it really is and get a feel for what I'm doing, looked like some 18650 cells without completely taking it apart.

Will it be any problem that one battery pack has been used for two weeks and one hasn't even been unboxed yet? I'm also completely clueless on bms's. Basically I just want to use half of (or maybe all of) my second battery pack in parallel to give me more range but with out swapping batteries and only having one charge port. Currently in the process of designing an area in the main triangle to store the battery and everything else. Metal working is a part time job of mine so it'll be pretty easy to make a housing.

Its all the power I need for the time being until I can get a better bicycle but would love some more range.
Any questions or advice is greatly appreciated.

Re: Newbie with an ebike

Posted: Oct 02 2017 6:25pm
by markz
Series is adding up voltage which means more speed. And you got to be certain your controller can handle it.
Parallel is adding up the Ah or distance you can ride.

And be very careful when connecting them as they need to be the same voltage, within 0.5V of each other. Thats what I do anyways.

You can charge it as usual, but will take double the time.

Re: Newbie with an ebike

Posted: Oct 02 2017 6:29pm
by flat tire
If you have several motorcycles you'll want something with a little more juice. I recommend Leaf 1500W for a hubmotor, not too heavy and I have mine running at 6KW on 20S RC Lipo for a top speed of nearly 60mph. Wheelies on demand. You'd love it, it's too radical for non moto people tho every single one who has tried to ride it has looped it immediately (lol).

You can mix the two packs, there shouldn't be a big cycle difference.

I don't recommend a BMS, they are all shitty and more likely to kill your battery than help out unless you spend big bucks. You shouldn't need to balance often anyway. Refraining from discharging the pack too much or charging it to peak full voltage will go a long way to help avoid balancing and improve the longevity of the battery. You can get an RC balance charger for when that's necessary (or even balance individual parallel groups with a lab supply). Bulk charge that baby. There are tons of CC-CV DC-DC converters you can hook up to a inexpensive high power DC 12 or 24 volt power supply (converted PC or server supply OR meanwell) to charge that thing at exactly the voltage and current limit you want.

Oh, I almost forgot. As a moto guy you probably hate the cheap shitty throttle that came with your kit. Do yourself a favor and get a Domino ev throttle, best electric throttle out there. You'll need a cycle analyst V3 to remap the ranges or there will be a dead zone stock due with most controllers. You'll want the cycle analyst anyway as it's a MUST HAVE to see your energy consumption, battery history, speed, and all that other stuff.

Re: Newbie with an ebike

Posted: Oct 02 2017 6:39pm
by VWhite
Thanks, this is just for the commuting stage right now but i can definitely see wanting to make an electric motorcycle in the future once I feel better with everything and understand more. My current setup (based on the display) will go 33mph on flat ground and that's too much for my rickety little mountain bike with basically no suspension.

So since each of the batteries already have the final power wires coming out, would those just be connected together to achieve what i want? Sorry i feel like such a newbie to all of this.

I still have the ability to return the new battery for my money back, but since I already have it and want more I might as well tinker and learn.

Yea.. a cycle analyst is on my list and ill check out the throttle too, thanks.

Re: Newbie with an ebike

Posted: Oct 02 2017 7:02pm
by markz
efraining from discharging the pack too much or charging it to peak full voltage will go a long way to help avoid balancing and improve the longevity of the battery.
That is a great reminder, I got a question along those lines.

Say you got a brick 10S4P battery of 18650, yet the rc balance charger only goes up to 8S.
I am thinking it IS possible to balance half at a time 5S as the battery isnt connected and should not do anything, or am I totally wrong there?

I tend to charge to 4.15V out of the max of 4.20V, but 4.10V is good also for longevity. But I wonder what the range difference from 4.1 to 4.2V. Simple as say 0.10V times 20Ah is 2Wh. So not much at all. Less then 50 meters I'd guess.

Re: Newbie with an ebike

Posted: Oct 02 2017 10:00pm
by flat tire
Yes you can balance part of a battery, just hook up the relevant balance leads. Make sure to hook up the + and - from each side before you hook the balance leads (double tap those balance leads since dedicated + and - may not be available). The reason you do this is because if the battery is significantly of balance and you don't hook up the main power leads you can get a lot of current traveling thru the balance traces in you charger which can blow them. I did that on a icharger 3010b.

To VWhite, look up "wire in parallel" on google images and then yes, you just combine the battery leads like that: + with + and - with -.

Re: Newbie with an ebike

Posted: Oct 03 2017 1:20am
by markz
That is great news!

Lets say you got 10S and you hook up rc to 5S balance like this below
1S pos or neg depending
2S balance lead
3S balance lead
4S balance lead
5S pos or neg depending
6S second round disconnect 1-5S and use 6 for pos or neg
7S balance lead
8S balance lead
9S balance lead
10S pos or neg depending

Great Im gunna do it that way then. I want to see how out of balance mine are because YES I did go down to 2.8V and should have been doing 3.2V instead.

No need to buy 10S balance charger then, a cheap 6S or 8S rc balance charger is all that needed.

OK back to the 'Newbie with an ebike'

Re: Newbie with an ebike

Posted: Oct 03 2017 1:45am
by flat tire
Just google image search 5s balance charge lead and you'll get the idea. Don't reverse polarity, just move the leads up so you're starting where you left off.

Re: Newbie with an ebike

Posted: Oct 03 2017 10:48am
by VWhite
This is where things get a little confusing for me. Wasn't expecting all this little wires in there.
20171003_102954-614x614.jpg (97.87 KiB) Viewed 1795 times

Re: Newbie with an ebike

Posted: Oct 03 2017 12:42pm
by flat tire
It's not that confusing. Each wire comes off a parallel group of cells. You can confirm the position by measuring from the end of the battery using your multimeter. The balance plug on that BMS should also have the wires in order.

Re: Newbie with an ebike

Posted: Oct 03 2017 5:10pm
by markz
Yeah its a bit confusing at first, but you have battery cans that are in series to make up your voltage, then you got a set of cans in parallel that are a mirror image to get your Ah or distance. Get a clear image in your head by searching endless sphere.
Each "Sense" wire or "Balance" wire is a very thing wire, connected to each "group" in parallel. In this case you are seeing one side, there would be a wire connected to each of the silver metal you see on the side you see and the side you do not see. The first and last the metal with only 2 circles are either neg or pos.
demo1.jpg (211.96 KiB) Viewed 428 times

Re: Newbie with an ebike

Posted: Oct 03 2017 6:42pm
by VWhite
Ok, so now that I've gotten home and unwrapped everything it looks like this battery pack(which I have two of that I want to combine but rearrange in my frame triangle rather than on a rear rack) is made of lggbmg11865 cells arranged in an 13s5p pattern. I want to eventually get it into an 13s10p pattern(I think)? They're connected with the nickel strip and spot welded. Can I clip the nickel wherever I want to(keeping them in the correct line of parallel) to rearrange into the shape I want the pack to be in and use wire/solder to reconnect them in series after I've gotten my shape?
I'm pretty sure I've seen it done when building a pack and I've taken note about how you don't want to apply a bunch of heat to the end of the cells, so I'd do it in between the tips of the cells on the nickel or just on the end of the nickel strip.
Just wanna make sure I don't mess things up, I actually spent a pretty penny on these battery packs and don't wanna waste them.
Also need to figure out some more about the bms stuff. I guess I can kinda see how the wires go in order throughout the series but just don't understand completely and if I'm trying to combine two of these packs that both have a bms, charging port with fuse, and power out how to correctly wire it all together to only one charge and power out port.
Please keep in mind that I do know how to solder, know the basics to using a multimeter and only have the supplied chargers that came with the battery packs.

Re: Newbie with an ebike

Posted: Oct 03 2017 8:53pm
by flat tire
Yes if you want to keep the same voltage it would be 13s10p. You can clip the strips, then soldering to them is just fine since it won't put much heat into the battery especially if you're quick. Just make sure you're careful and everything is secure and well insulated with no possibilities for a short before you mount it.

Re: Newbie with an ebike

Posted: Oct 03 2017 9:25pm
by VWhite
Any specific wire gauge you'd go with for my application?

Re: Newbie with an ebike

Posted: Oct 04 2017 7:09am
by dogman dan
My advice is to back off a bit till you learn a lot more. ruining a battery poking around or trying to reconfigure it is costly, and stops you from riding. Don't mess around with those little wires, unless you see one broken.

To better carry two batteries, for now, get a good sturdy set of panniers to carry the batteries, and make your rack more sturdy somehow. Get the weight lower. One option that works really good is the cheaper motorcycle bags that look like leather. Another one is ammo boxes as panniers, or metal pannier baskets.

You can make a Y connector to run both batteries together, just make sure both are full and balanced, before you hook them together. You will still have to charge them separately. Just connect the two final power wires coming out to parallel them.

Or just run them one on the way to work, one on the way back.

Balance your packs by letting it sit for half an hour after the green light goes on, then unplug, and re plug to restart the charger. If it does not restart, ride around the block to start it back up. While its sitting, the bms is discharging the higher charge cells, when it starts back up, it will fill the lower charge cells a bit more. if way out of balance, it will take several repeats of this process. No need to manually balance your pack yet. It can be something to learn how to do later though, when the pack is on its last legs and won't balance anymore.

If your pack holds full charge after its unplugged, its balanced. It should be at or close to 54.6v full, and hold at least 54v after you unplug. Any less, it needs to balance more. Running 100% out tends to lead to a need to balance, so the more often you charge, before you are all the way empty, the less it tends to unbalance itself. Charge at work was my solution, most days I used 50% to work downhill, and 75% back home up the hill.

Later on, when you need to replace your batteries, you can get a triangle pack. For now, carry the battery lower, on a rack that does not sway, and it will feel ok to ride it.

Later on maybe, you can get a welder and start rebuilding steel bikes into ones that handle better by lengthening them 6-9 inches so they have wheelbase more similar to motorcycles.

like this one.
6-1-2015  Schwinn Cruiser with 52 t crank.JPG

Re: Newbie with an ebike

Posted: Oct 05 2017 12:52pm
by markz
Sturdy panniers is a must when carrying batteries in pannier bags.
I had some 1/4" wood protecting my packs 24Ah of 1.6Ah cans.
I tore up mine very quickly. Next time I will zip tie the battery to frame to take a good chunk of the weight of the battery off the bag itself, and split the pack into two, one for each side.

Re: Newbie with an ebike

Posted: Oct 05 2017 10:44pm
by lester12483
Be sure to invest in Kevlar tires and thicker puncture resistant tire tubes. It really makes a difference. Getting a flat on an ebike is no fun.

Re: Newbie with an ebike

Posted: Oct 09 2017 7:53pm
by VWhite
Firstly, I do appreciate all of the advice and the concern about my lack of knowledge, but I love to learn new stuff and believe I can tackle this project.

I really do want some panniers for my bike but they'll have to wait for now. Riding motorcycles I know how handy they are and I dislike backpacks, I had saddlebags, tail bag and a tank bag on my favorite rocket and could do everything i needed at the store except most the bulk stuff(haha, even used to carry 20lb bags of dog food just because I didn't like driving in my truck).

Already got 1 flat but luckily I was pulling into the guard gate at my work and only had to walk it about a 1/2 mile. Got a ride to the store and patched it at work, has held up a few weeks now.

Guess I'm gonna go ahead and make a build thread. >W commuter.

Re: Newbie with an ebike

Posted: Oct 12 2017 10:40pm
by VWhite
Well y'all can go ahead and laugh at me and say I told you so. I have no idea what happened. Took one battery pack(65 cells) apart into strips of 5p so I could start making my bigger pack, all tested out to 4.12 afterwards and thought everything would go smoothly. Started putting them in 10p and stacked them up to start putting in series and before I started putting them in series checked voltage again just to make sure and everything reads 0. Even one string of 5p that I did absolutely nothing to except snip balance leads off.

Completely confused and frustrated. 450$ battery pack down the drain.

Re: Newbie with an ebike

Posted: Oct 12 2017 10:47pm
by markz
Did you snip ONE wire at a time?
Also did you make sure and triple check polarity, pos (+) and neg (-) of each section before reconnecting them?

Re: Newbie with an ebike

Posted: Oct 13 2017 8:08am
by VWhite
Yes and yes.

Re: Newbie with an ebike

Posted: Oct 13 2017 12:59pm
by flat tire
I doubt you fully discharged them in a short time unless there was a lot of heat and probably some smoke. And they probably wouldn't read full zero either. Guessing this is some other issue.

Why don't you post about this on the eevblog forums? From this point on I'd expect better advice from over there.

Re: Newbie with an ebike

Posted: Oct 13 2017 6:29pm
by markz
Well then you need to go through it all one step at a time.
I would take apart the battery until you got it down to the smallest modules or smallest bricks.
Do a quick inspection of the wiring harness.
Like for myself I soldered together 15S2P so that is one module/brick, I would take off the Gorilla Tape and heat shrink for each one, and look at the connections, and clean with isopropyl alcohol as you go, buy some electronics horse hair brushes.

Measure with a Digital Multi Meter each can and see what voltage you get.

I would take off the shrink wrap until you get to the tabs, then measure each and every can.

Re: Newbie with an ebike

Posted: Nov 07 2017 7:09pm
by VWhite
Well I got some good news. Working on my motorcycle over the weekend and needed to use my multimeter a few times and I could tell something just wasn't right, bought a new multimeter and figured it out real quick. Turns out my multimeter broke somehow and I only thought I had ruined my ebike battery.

After I thought all my cells were bad I was frustrated and didn't think I had anything else to lose with them so I rigged it back up to an 13s5p pack in an attempt to recharge them with my charger. Charger said they were charging for a few minutes then stopped but I kept getting around 0.3v and dropping on the whole pack so I just gave up and set it aside. Haven't touched it in a few weeks and now the new multimeter says 54.4v on the pack :D

Very very happy. Now I get to continue on like I had planned in the beginning by making it an 13s10p pack this weekend 8) .

Re: Newbie with an ebike

Posted: Nov 07 2017 8:13pm
by markz
Install a fresh battery, and fresh fuse or fuses. Always good to have 2 DMM's