EV Global upgrade

evglobal19 · Apr 3, 2019

So..... I bought one of the 24V bikes more for the look with the idea of building it out/up. I am a novice tinkerer and was thinking about the 48V 1,500 W Rear Hub. I was told the old Heinzmann was fine and the controller was shot. I suppose I could find a generic 36V controller and skip the 'extras' like headlight etc. I'm about 200lb I would think 20-25mph is fast enough on mostly flat city roads. Would prefer electric only with pedals as secondary. Zippy enough to move about any traffic and distance enough for 15 miles before charge. That's the rational side of my brain, safe commuter option. I'll save the Mr. Hyde for another post.
My newbie questions are:
1. is a 1,000, 1,200, or 1,500 W Hub an appropriate choice
2. isn't a 48V better all around than a 36V
3. based on above what amp hour battery makes sense. They go up quickly in $ and the 1,500 'ad' says 48V14aH min. I would probably start with SLA's (I know) if I went blind since cost of Li too high to make mistakes.
4. how do I "know" or where do I look for actual/important specs on an eBay hub motor and controller? amps, Nm, peak, continuous, lots of letters that make little sense to me anyway.
5. Budget I suppose would be about $500; 48V1,500W Hub about $200 and eventually Li battery seems close to $300.

If spend a good time on auto forums so hopefully my placement and etiquette for this question is reasonable. Since this is a build for fun I'm happy to give back in whatever way I can.
Steve

amberwolf · Apr 3, 2019

evglobal19 said:
So..... I bought one of the 24V bikes more for the look with the idea of building it out/up.

THere are a few threads about EVG upgrades to brushless hubmotors here on ES;

I was told the old Heinzmann was fine and the controller was shot. I suppose I could find a generic 36V controller and skip the 'extras' like headlight etc.

Sure. Just keep the new controller the same current limit as the old (if it was also 36v; if it was 24v you may need to lower the current limit by the same ratio you increase the voltage), to keep the wattage about the same so you don't overheat the motor.

I am a novice tinkerer and was thinking about the 48V 1,500 W Rear Hub.
<snip>
I'm about 200lb I would think 20-25mph is fast enough on mostly flat city roads. Would prefer electric only with pedals as secondary. Zippy enough to move about any traffic and distance enough for 15 miles before charge.

Most likely the Leafbike 1500w kit would do what you're after, if you get a good enough battery.

That's the rational side of my brain, safe commuter option. I'll save the Mr. Hyde for another post.

You might need a different bike for the Hyde build; depends on what you're after. If you just want quicker acceleration you just get a bigger battery and controller; the motor could still do that. If you need higher speed, the same motor can do that with a higher voltage battery and controller...but it'll get hotter doing that continuously. If you find it gets too hot you can do various cooling mods. But faster speeds need better braking, better suspension, etc., etc.

Most likely...you'll end up building a second bike anyway, once you ride the first one long enough, and figure out waht you want to be different. Then the third bike will be even closer to what you want (as what you want changes, too), and so on.

1. is a 1,000, 1,200, or 1,500 W Hub an appropriate choice

1500 would be better, as it gives you more options for the Hyde version later, and easily handles the power you need now.

2. isn't a 48V better all around than a 36V

Uusally, or 52v (almost the same as 48, but slightly more power/capacity). Lower currents are required to get the same watts, and faster speeds are possible without "crazy windings" of motors (or giant-diameter wheels), for hubmotors, or using middrives with higher gearing sprockets.

3. based on above what amp hour battery makes sense. They go up quickly in $ and the 1,500 'ad' says 48V14aH min. I would probably start with SLA's (I know) if I went blind since cost of Li too high to make mistakes.

Assuming around 25wh/mile+ for power usage, then 15 x 25 = 375wh minimum battery. for a 48v battery, that's 375 / 48 = about 8Ah minimum size--tha'ts 8Ah *usable*, which the SLA won't give you, unless you use big heavy 18-20Ah SLA batteries. It's been a while since I used those, but IIRC they commonly weigh at least a pound for every Ah. For 48v, at 20A, that'd be 80lbs of batteries. Even if it's only half that, that's still 40lbs. You'd have to mount that as side panniers low down (like around axle height) to keep it from really screwing up the handling.

The one thing to NOT skimp on is your battery, because it determines many of the capabilities of the bike. It's size and weight determines some of the handling characteristics, because those also determine where you can put it, and weight in some places makes handling bad, even unsafe on some bikes at some speeds.

But mostly because the battery has to supply the power that runs everything, and if it's not sufficient, the bike will suck.

So you want one that can easily put out the current of your currents without sagging in voltage, and that has enough capacity to go at least half again the distance you want to go now. As batteries age, they decrease in capacity, and thus range (and ability to put out enough current without sagging). The smaller the battery, the harder it is on it for normal usage, and the faster it ages.

4. how do I "know" or where do I look for actual/important specs on an eBay hub motor and controller? amps, Nm, peak, continuous, lots of letters that make little sense to me anyway.

First, assume they're all lying, and/or have no idea what they're talking about.

Second, they wont' be giving torque specs, or accurate current or wattage limits, etc.

So...the best way to find a kit that does what you want, is to find a bike on here that does what you want, and then use what they used.

It's not much more time-consuming, and more certain to get the result you're after. The http://ebikes.ca/simulator will help as well (though you'll want to read the whole page to understand what it's showing you).

skeetab5780 · Apr 3, 2019

EVG nice! Ive owned a few of these bikes and they are good commuters!

I drove all the way into vermont to buy my first one off craigslist, it was perfectly stock and i tore everything off of it except the frame and seat post and built it from the ground up with newer parts

The old brushed hubs are loud and slow and pretty much history now, they have good torque but who cares.

Id get 48v 1000w rear brushless hub kit and 48-52v battery atleast 15ah 20ah preferred

Getting a good front fork is hard since the headtubes on these frames are sooo long! I actually cut one frame down shorter 1/4” off top and bottom just to fit a used fork with cut steerer. The geometry of the bike only lets you use an 80-100mm front fork, the back ends are a tad low for taller riders like myself

The battery storage with latch cover is the hands down best part about the frame so size your battery to that size.

The rear dropouts are strong so you dont need torque arms, and the pannier mounting holes can be adapted for a rear disc brake fairly easily!

The downside to these bikes are that they are very heavy, even when you remove stock components and the plastics and cut off unwanted metal from the frame, there is still an extra 10 pounds you have to live with that ultimately made me stop using them. Also it has no rear suspension

The lower frame crankset area and lower swingarm are prone to get internal rust, and it can be annoying. This was an issue on one of the frames i owned. There was no way to get the rust out and it shook around in there constantly

evglobal19 · Apr 4, 2019

I am so pleased that everyone has chimed in. It's slightly depressing to post and hear crickets! I know the EVG is heavy but I'm a sucker for old school looks. Sort of Mid-Century modern design so power will have to compensate for weight. I totally appreciate the advice and opinions of the community. When I recently bought the EV it came with a second frame and some bits so I will have spares if anyone needs. My intent all along was to use the frame and structure similar to a Restomod with cars.

The Ebay seller "Voilamart" lists as follows: 48V 1500W/750W hub 45 N.M torque and recommends 14.5Ah battery. one reviewer said, standard 9C hub motor with disc brake and freewheel attachments. the controller is a 15 FET model with 7.1mOhm/100V/300 Watt FET's. whatever all that means... And while I was thinking a 48V 20Ah battery would be best maybe an 18Ah is enough. that ad says: output DC 54.6V 2.0A LiPo with charger etc for $325 and the 20ah start at $450.
Does this combination without any more available information make sense?

Funny thing is also saw the 72V MXUS 3000W motor for $359 but that's another story...

amberwolf · Apr 4, 2019

evglobal19 said:
When I recently bought the EV it came with a second frame and some bits so I will have spares if anyone needs.

Then you have your Hyde frame, once you start that project after this one feels "boring". :lol:

The Ebay seller "Voilamart" lists as follows: 48V 1500W/750W hub 45 N.M torque

At what current?

Just so you know, you only get a specific torque with a specific motor at a specific current (which takes a specific voltage and load). Check out the http://ebikes.ca/simulator for how this works.

Since "1500w/750w" doesn't specify conditions, etc., then most likely it means 1500w peak, 750w continuous. However, wattage ratings from vendors really mean nothing, and are not that useful except as a basic guide to approximately how large a motor it might be. See https://www.ebikes.ca/learn/power-ratings.html

the controller is a 15 FET model with 7.1mOhm/100V/300 Watt FET's. whatever all that means...

15FET is basically a 12FET with one extra FET on each phase to help with recirculation currents (so the diodes in the FETs dont' heat as much).

7.1mOhm is the resistance of the FETs. 100V is their maximum voltage (so generally better to run them some percentage, like 15-20%, less than that, say a 72v pack at most).

300watt isn't a rating taht makes much sense, so I suspect a typo or else a made-up number. If it is a "real" number, it might be the heat a single FET could theoretically dissipate under ideal lab conditions, according to the spec sheet. The actual conditions inside the controller are nowhere near ideal, so numbers like that off the spec sheet aren't useful to the end-user.

Or it might be the amount of heat the controller as a whole actually creates at max voltage and current (though it's unlikely they have bothered to test this). If so, that would cook it pretty good in a short amount of time. If enclosed in a bag it could even start fire. So it's probably not that, and is probably a typo, and whatever number they meant to put there is *intended* to be the max amount of power that can be pulled thru it to the motor.

And while I was thinking a 48V 20Ah battery would be best maybe an 18Ah is enough.

The Ah rating doesn't mean anything except how much capacity it has (which is just part of how much range you get out of it).

The rating you need to worry about is the A rating, which is how much current it can supply, and you want that number to be higher than your system will ever draw, or else you are pushing the battery hard every time you use it at max load. That ages it faster, heats it up inside, causes more voltage sag whcih reduces the power you actually get out of it, and reduces teh actual capacity you get out of it (reducing your range).

that ad says: output DC 54.6V 2.0A LiPo with charger etc for $325

2.0A would be useless. If it's actually "A" then it's amps output, and would be destroyed by using it on a >100watt system. If it's actually "Ah" then it's only a couple miles range at best.

Does this combination without any more available information make sense?

You don't want to buy any battery without "more available information". Otherwise you could just be throwing money away.

At minimum, you need to know what the *real* continuous current (A) rating is, and what it's *real* peak current rating (A) is, and what it's real capacity (Ah) is at what current (A) draw. Knowing it's dimensions and shape and weight are useful too, so you can figure out where to put it. (you don't want it on a rear rack; it'll wag the back of the bike around). If you can get a pack that you can install in the space the old SLAs fit in (even if you have to modify the frame and plastics to expand that area a bit), then the bike will ride much closer to the way it was intended to.

Funny thing is also saw the 72V MXUS 3000W motor for $359 but that's another story...

If you're running them in 20" wheels, those might be ok, but they are huge and heavy and there are better motors if you want higher power. (I've broken axles on two of them, and flatted axles suck for high power anyway).

evglobal19 · Apr 4, 2019

Can you point me in the right direction for 48v battery options then?

evglobal19 · Apr 5, 2019

Here's one on dhgate.com
Model: D034 Li-ion E bike battery
Nominal Voltage and Rated Capacity: 35AH 48volt 25Ah
Configuration: 13Series 8Paralles 13S 10P
Cells: Brand 18650 3.7V 2500mAh Cells (13*9= 104 pcs cells for this battery)
BMS : 30 Amp max continuous and 100 +|- 10Amp max peak current
Charge current: 2-5A
Charge Cut-off Voltage 54.6V
Discharge Cut off Voltage: 36.4-39V

Lithium battery built in cells and 30A BMS with 25CM discharge naked cable or soldered default discharge connector and, 1 X 54.6V 3A fast charger with AC plug.

It's a blue rectangle 8kg 245*160*70mm. A red a black wire and charger plug.

Yes? No? Maybe?

amberwolf · Apr 5, 2019

evglobal19 said:
Nominal Voltage and Rated Capacity: 35AH 48volt 25Ah

Seems they don't even know what capacity it is: 35Ah? or 25Ah?

Configuration: 13Series 8Paralles 13S 10P
Cells: Brand 18650 3.7V 2500mAh Cells (13*9= 104 pcs cells for this battery)

THey also don't know how many parallel cells it has. Says 8P, 10P, and 9P all in just two lines.

Since they dont' say *what* brand (or model) of cells, you can assume they're random junk they got from wherever (too many packs are actually made from recycled junk cells), and as such may not even be the same cells throughout the pack. Even if they are the same, there's no way to know what they cells are actually capable of. They may or may not really be 2500mAh capacity, and there's no info on how much current they can actually put out.

BMS : 30 Amp max continuous and 100 +|- 10Amp max peak current

For instance, coudl they really do 100A peak, and for how long, without overheating? (shoudln't matter for your present build, but it's just one more thing you can't tell from their "specs")

Discharge Cut off Voltage: 36.4-39V

It's not normally a range of voltages, for LVC, it should be a single voltage.

Yes? No? Maybe?

I'd have to give that company a resounding NO. Sounds like they're clueless, like most of these places.

Personally I'd recommend known places like http://EM3EV.com which has been a reliable vendor (a pack by them, that I got used from someone else, is now at least several years old and still working, including the charger that came with it), whose only serious disadvantage is that they are based in China (though not actually a "Chinese" company as such), so shipping times/costs are still the same as the other companies based there. But quality of packs is higher, and detailed information should be available, though they can be a bit laggard in response times, and because of the quality the cost is higher.

I recommend contacting them with your specific needs (controller max current, range needs, etc.) so they can help you get the right pack, or having one custom made to fit the space you have available inside the frame (best solution, if it can be made to fit and still be big enough).

Other people like Luna Cycles in California, and have had good luck, though I myself don't trust them, having seen too many issues posted about here on ES with their "customer service", but I have no direct experience with that. THe one pack I have of theirs has issues with it's BMS, but not apparently with the cells themselves.

http://ebikes.ca has their LiGo packs that they designed and had made, but I think the rest of the packs they sell are not designed or made by them, so I don't know what quality they have, other than that they hopefully would have picked a pack vendor that they could trust. The LiGo packs have no advantage for you, except that they're modular so you could put them wherever you want...but they're 36v, not 48 or 52, so I wouldn't use them on your project. AFAICR the other packs they carry are rackmount, but you coudl adapt them to other mounting methods, and might even fit in teh frame space you have if the space is modified to fit them. (might have to take them out of their casing)

There are other vendors discussed in various "where do I get a battery" type of threads, if you want other options; I don't remember any of their names or which ones have had problems or not. The Vendor Relations subforum has threads about various vendor problems (with a few success stories), that might help pick reliable ones, or at least which ones to avoid for whatever reason.

evglobal19 · Apr 25, 2019

so I did buy one of the voilamart 48V 15ooW kits that should be delivered any day now. although they don't give specific information and I'm waiting for an email reply on the specs, on Amazon reviews it says controller is a 30A. Question is then when looking at batteries there are three stats, BMS, continuous or nominal amps and peak amps???

UPP has a 48V20aH with a BMS of 50A, continuous discharge of 50A and peak at 125A
UPP has a 52V20aH at 50amp continuous and 125A peak
another says 52V 20aH BMS 40A continuous 40A peak 100A

if the controller is "actually" 30A should battery be rated lower, same or higher ok?

also, seems that at 1500W vendors are "suggesting" at least 20aH and higher of course for more $$ even when the kit says 14.5aH minimum.
help....

amberwolf · Apr 25, 2019

First, I would take all of the "ratings" of battery vendors with a block of salt. They may give the max rating of a pack based on the ratings of a single cell in open air, instead of derating it for the heat containment the pack will cause, for instance. So...it might be safer to cut the ratings by some percentage, for estimating how they'll work in your system. 20-25% would be a safe margin most of the time...and if the pack happens to really be able to perform to the stated specs, then you have gained margin for aging degradation.

The same is true of capacity ratings.

evglobal19 said:
if the controller is "actually" 30A should battery be rated lower, same or higher ok?

The battery must be capable of providing more A than the controller can pull (really, the same, but more is better as it allows for aging and variation in controllers and packs).

If it cannot, then the controller will damage the pack when it pulls more current than the pack can handle, by heating the cells more than they're designed for, aging them prematurely. It will also cause greater voltage sag, which may cause the pack's BMS to shutdown and stop the system from working at all, until it is reset by charging. (some BMSs will restart as soon as the sag goes away, some will not). Overcurrent can even damage the BMS (if it does not shut down on overcurrent; they don't all, even when they state limits), if the overcurent lasts long enough, as the FETs overheat and can either fail or come unsoldered (which can cause other failures).

also, seems that at 1500W vendors are "suggesting" at least 20aH and higher of course for more $$ even when the kit says 14.5aH minimum.

That is because (generally) the bigger (in Ah) the pack, the more current it can deliver with less strain on the cells.

evglobal19 · Apr 26, 2019

Firstly, thank you again for being so considerate in answering questions, I really appreciate the feedback and information!!! So if in fact the controller operates at 30A then a battery with a "stated nominal discharge of 40 (or more) given the wiggle room of 25% should 'hopefully' run at 30a and not irritate the motor.

Ok, moving on.. Li-ion and LifePo, I know everyone has differing opinions but since you've been kind enough to reply I would appreciate your opinion. I seem to see that LifePo have slightly lower V ratings but seem to have more longevity. Meaning the pack size might be slightly larger but if that is not an issue better? Worse? Equivalent? Hesitate to ask since it seems hotly contested but for many of us it is also one of the most costly components of a build and obviously the one most important piece of having an e-bike.
Thanks again...

amberwolf · Apr 26, 2019

evglobal19 said:
So if in fact the controller operates at 30A then a battery with a "stated nominal discharge of 40 (or more) given the wiggle room of 25% should 'hopefully' run at 30a and not irritate the motor.

Just to be sure you understand, the motor pulls however much current the load requires, and the controller limits that current to prevent damage to motor and battery.

So the battery simply has to be able to supply at least as much as the controller can ever possibly draw.

Li-ion and LifePo, I know everyone has differing opinions but since you've been kind enough to reply I would appreciate your opinion. I seem to see that LifePo have slightly lower V ratings but seem to have more longevity. Meaning the pack size might be slightly larger but if that is not an issue better? Worse? Equivalent? Hesitate to ask since it seems hotly contested but for many of us it is also one of the most costly components of a build and obviously the one most important piece of having an e-bike.

The battery is the heart of any EV (actually, any battery-powered system), and if it isn't good enough you can't get the performance required out of the system.

Battery type desired depends on many things, and the best I can recommend is to read as many threads arguing about which is better as you can stomach.

All the possible reasons for each have been discussed to death, and aren't going to change until a new chemistry with all the right magic stuff in it is commercially sold (not just developed in a lab).

Chemistry isn't everything, either, because even if you get "the very best" chemistry made by crappy companies, or even "the very best" cells assembled crappily, the battery resulting from them will still be crappy.

All I can say is that I've used most chemistries except for LTO (lithium Titanate) so far, in good and bad quality versions.

My preference right now (and for hte past few years) is for the old EIG NMC 20Ah pouch cells, partly because they have been tough and reliable, and partly because their factory hardware is by far the easiest way to put a pack together that I've ever seen. Catch is they're hard to find used (people that have them probably don't want to let go of them till theyre really dead), and way too expensive to buy new, even if you can get the factory to talk to you for less than a shipload of them. They also don't fit inside most bike frames, cuz they're big flat slabs that make big blocks for a pack. But they work for my cargo bikes, trikes, trailers, etc.

RC Lipo works fine, as long as you already know how to deal with them (fire risk, etc). But their lifespan is short when used hard. (so are many 18650 types). I'm still using some old packs that I've wired around bad cells in, for my yard tools and powerdrills. WOuldnt' work on a bike anymore.

I also ahve an old A123 (lifepo4) pack from EM3EV, and it still works after several years (and I got it used), but these packs aren't made anymore. The cells still are, from stortronics, but then you have to connect them...there are threads abotu that, too.

There are probably dozens of 18650 cell types, and each one has it's own good and bad, depends entirely on your usage needs (you either get high current or high capacity for the most part, and to fix either one you add more cells in parallel). LOTS of threads about those, and the many ways to test and assemble them. I have a small 18650 pack but it can't handle much of a load. Don't remember which cells it has.

"Li-Ion" doesnt' really mean anything other than it's a lithium based rechargeable battery. So...whenever you see that you have to figure out what chemistry it is, and what it's actual specs are (discharge, charge, capacity, etc), to see if they'll work for you.

Most vendors dont' even say what kind of cells are in their packs, and most of their "specs" are marketing-speak...as we've gone over already.

Makes it hard to judge if a pack is really appropriate for a build until you actually install it and test it. :/

FWIW, even with Lifepo4, there are many types of cells, just like the 18650 (in fact, some of the 18650 are lifepo4, others are NMC, LiCo, etc etc).

Used Nissan Leaf cells can be a good bargain, there are a number of builds around here powered by them (including Chalo's cargp bike, I think). If I didn't have the EIG stuff, I'd probably get Leaf cells. Like the EIG cells, though, they are flat blocks that make big blocks.

Hopefully that's confused .... er, helped you some.

:lol:

Alibro · May 14, 2019

I'm just chipping in here to see if the kit has arrived yet and if so how did it go.
I was looking for a 1500W motor myself and came across the same kit on ebay so I'm looking for some feedback on it.
I already have a 48V battery pack suitable along with a 1500W controller and various bits so I was only looking for a motor but this kit is so keenly priced it is cheaper than a MXUS motor alone.
Is it too good to be true?

evglobal19 · Jun 12, 2019

Sorry, have been otherwise distracted and didn't see post. My impression is that the kit is nicely built, solid components, good instructions etc. and yes at $212 it is fully stocked (except battery). I just found a 48V23aH battery stalking around local CL. Actually bought a whole 1kw kit with 27" hub just for the battery. Local, cash, and same day. Sure the driven only to church by an older lady story may not be true but it was worth the shot. Have to charge battery and connect wiring to test it all out. Only issue for me is that the battery is a triangle and the frame doesn't fit it. Got a rear seat rack and will mount it there although not the clean look I was going for. may need to "open" the midframe and hide it but not sure yet. Figure got to make sure it all works first.

evglobal19 · Jun 12, 2019

Of course as predicted before this one is running im already looking an another project with, yup, more power. :bigthumb:

The pedelectric EV Global is good for passing as a bicycle and may even be zippy enough for an electric smile but... Saw a vintage moped that looked cool but didn't want the 50cc noise and smoke...

started by yanking off the motor now in a box. and most of the other parts to strip and recondition what I can. PITA to find parts or NOS so refinishing has to be the way.

cheapest way to go is to get a BLDC and mount with simple chain drive, more 'simple' is a hub wheel setup and this is where the fun begins.

evglobal19 · Jun 12, 2019

I've spent way too much time looking and reading and the more I read the more confused I get so I'm asking the E-gods here for some help. I understand that what a manufacturer or sales person says is always suspect but have to go with what I read. I'm 6' and about 195lb, the bike frame as is maybe 35lbs naked.

The Sachs has 17" rims so I figured looking at an e-motorcycle hub motor would be easiest retrofit (assuming dropout and width are close match). Couple of folks can provide a 17" (QSmotor, NBPower, UUMotor) in various wattages. Since the EVG is 1500W I was looking at 3kw or 5kw. Each of these are sold at 48V, 60V and 72V but there are option for higher V as well. Here's my leaning so far: NB 3Kw in 60/72V, sine wave programmable controller at 80A/100A. Doesn't give more info on controller for continuous or max discharge. Stepping up to the 5Kw the controller says 80A/150A at 60V and 72V respectively. Perhaps I'm wrongly assuming that as a "kit" the 60 and 72 volt kits are properly matched.

the obvious questions are....
(1) For commuting and fun how different would the 48V, 60V and 72V combinations work. We all know that as the V goes up so does the $$ quickly. Don't want to have to spend $1,000 just on battery. I have no plan for 60mph riding or trying for more than 15 miles or so in distance.
(2) what would be the 'minimum' amp hours at the various voltages and would 48/52v just be a recipe for disappointment?
48V/3kw
60V/3kw
72v/3kw
48v/5kw
60v/5kw
72v/5kw

amberwolf · Jun 12, 2019

evglobal19 said:
Since the EVG is 1500W I was looking at 3kw or 5kw.

Why specifically are you targeting those wattages? If it's just because they're higher...well, they may not do what you want (or may be way more than you need).

First you have to decide what this is going to be registered as--moped or motorcycle (or whatever your locality deals with them as), and then what kind of speeds you want out of it, and what kind of acceleration you need to match traffic acceleration, etc.

Then that, along with the weight of bike and rider, and aerodynamics, wind, and terrain, will tell you how much power you need.

THat simulator can help you figure out which power level you need, though may have to use some of the custom settings for controller and battery to make them do higher power levels.

In general, 3kw could get you something around 40mph ish; acceleration might be quick enough--SB Cruiser is about 500lbs with me on it and 4kw gets me 0-20MPH in a few seconds, it's enough to match the acceleration of the traffic around me in most cases, which is safe enough to keep me from being run over, or get drivers angry at me for "being in their way". (I still need more power to do the same accleration with a heavy load, or a trailer full of cargo or dog(s)...that'll come eventually when I get stuff that the current power levels don't keep breaking).

5kw might get you 50mph ish, and acceleration could be quicker.

Keep in mind that the faster you go, the power level goes up exponentially to do it, which means it also eats your battery that much faster too. So to get the same range you need a much larger pack for the latter compared to the former.

(1) For commuting and fun how different would the 48V, 60V and 72V combinations work.

Whar's your definition of "fun"?

What's your definition of "commute"?

FWIW, it's not really the volts that bring cost up, it's the total wh of a pack, or the total watts of a system. It *can* cost more for really high voltage stuff, but that's still more about the total power it can do than the voltage itself--most people aren't using 100v+ controllers for toodling around at a few MPH, they're looking to rip down the street or offroad, at high accelerations and fast speeds, *or* pull hefty loads at a normal pace, either of which needs power to do.

(2) what would be the 'minimum' amp hours at the various voltages and would 48/52v just be a recipe for disappointment?
48V/3kw
60V/3kw
72v/3kw
48v/5kw
60v/5kw
72v/5kw

Couldn't say without knowing the range you need and the speeds you're after, terrain, etc., because all those determine the wh/mile and the miles times that give you total wh you need, which then tells you the ah you need.

The specific battery (cells it has, chemistry, etc), for a specific power output, may need a certain number of parallel cells to do it (and thus a certain Ah), so it doesn't sag in votlage and be unable to provide the total power you're after. It is sometimes (maybe often) difficult to find out what cells are *really* used in a battery pack, or waht the packs *real* specs are, until you have it in your hands and can test it yourself with the system it'll be used on.

If you trust the seller's output ratings, then you'd buy a pack that can supply the current needed to run the system at the max power you'll draw from it, and has the total wh needed to give you the range you need. We still have to determine what those are, though.

evglobal19 · Jun 13, 2019

Yes, pretty much the “newbie, bigger is better” thinking.
Just me on a moped frame so total weight is maybe 300lbs. Getting in and around traffic is the goal so 40mph should be about tops. Faster 0-40 would be great. Limited short inclines in Chicago so hill climbing not as important and only on road.

3000w or 5000w was mainly because I can find 17” hubs that would fit. If 3kw is plenty I’m good with that. The manufacturers list 3kw at 48v/60v/72v availability. If 48v drives the hub sufficiently that’s great and if over bolting it to 52v gives a slight bump that’s good. If 300lbs and 3kw is “seat of pants” noticeable faster at 60v that’s fine too. Jumping to 72v bumps battery cost and size.

I’ve read about Ah capacity and some advertisers use “minimum” numbers. If I can get 20 miles between charges that should be enough. From what I see online 20ah would be enough if I’m reading it right. Again, if I remember reading there is a calculation for watt hours and hub draw that gives potential distance.

Since I would like this to be more of a performance build than the pedelec at 48v/1500w for getting around the city.
I apologize if my rambling sounds typically uninformed and I’ll go back to the calculator and plug in more specifics. Really looking for opinion for good, better, and bordering on way too much wheelie popping and breaking traction.

evglobal19 · Jun 13, 2019

Guess should say that first part of previous post would be minimum and wondering about options to incrementally push performance up.

Voltron · Jun 15, 2019

The frames of an EVG make a great platform for upgrading. With modern battery, motor, controller, bigger crank, and upgraded brakes (I added a disc brake mount to the rear) they're fun to race around, esp in pairs. The frames are incredibly stiff... Never a hint of wiggles no matter how hard they're pushed....

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