couple of battery pack questions.

Batteries, Chargers, and Battery Management Systems.
Kenny'sID   100 W

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Re: couple of battery pack questions.

Post by Kenny'sID » Oct 31 2017 7:03pm

This converter has been sitting at USPS ICS Chicago since the 21st of October. As I understand it, that is not necessarily customs but they are close to each other so could be. But anyway, wturber, did yours get stuck Ike that? I've never seen anything sit at the NY location, where most of my pkgs move through, for nearly that long . Is it customs sensitive for some reason?

Also, while I'm here, I assumed hooking the converter up is pretty straight forward, but should probably ask if there is anything I need to know? Since I have a couple of bikes, I'll likely make the converter portable to move it with the battery pack, at least until I see how it goes. A thought has also been to mount it in a trailer that I generally use when I take either bike out. I like that you have yours out where it cools the best but do you think putting in my trailer would cause cooling problems, and even going so far to cover it with a vented PSU type cover so it doesn't get funked up when I load the trailer? Add another fan maybe or cut a vent in the trailer wall? Necessary, not necessary?

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Re: couple of battery pack questions.

Post by wturber » Oct 31 2017 10:11pm

Kenny'sID wrote:This converter has been sitting at USPS ICS Chicago since the 21st of October. As I understand it, that is not necessarily customs but they are close to each other so could be. But anyway, wturber, did yours get stuck Ike that? I've never seen anything sit at the NY location, where most of my pkgs move through, for nearly that long . Is it customs sensitive for some reason?

Also, while I'm here, I assumed hooking the converter up is pretty straight forward, but should probably ask if there is anything I need to know? Since I have a couple of bikes, I'll likely make the converter portable to move it with the battery pack, at least until I see how it goes. A thought has also been to mount it in a trailer that I generally use when I take either bike out. I like that you have yours out where it cools the best but do you think putting in my trailer would cause cooling problems, and even going so far to cover it with a vented PSU type cover so it doesn't get funked up when I load the trailer? Add another fan maybe or cut a vent in the trailer wall? Necessary, not necessary?
I ordered mine from Amazon and paid about $15-20 more for the convenience of rapid delivery. I was kinda chompin' at the bit to play with this stuff. Other than that, its a matter of setting the controller so that the low voltage cutoff is well below where the batteries will ever dip (I have that documented somewhere for those batteries) and setting the output voltage where you want it. I've set mine to 54v.

There's really nothing special as far as hooking it up. I'd say to make sure you have the inputs and outputs screwed down well and that you check them periodically. That's really the only SNAFU I've had. One of the input wires came loose and I was befuddled for a bit until it sparked upon momentarily re-connecting. It might be a good idea to crimp on some slotted connector of some kind rather than just using bare stranded wire as I have.

I've only ever had the fan come on once and that was just for a moment. By the time I bent down to gawk at it, it had stopped. The converter never seems to get warm. The motor can get up to 107 deg F, but the converter seems to always be about 2 degrees above ambient temperature. Maybe that is because it gets good airflow? I dunno. So it's anybody's guess how the cooling would be if it were in another place. The same goes for whether the one fan is enough. Given how cool mine seems to run, my bet is that you have a lot of flexibility. So I'd do what seems sensible and then just check to see if unit is getting warm and/or if the fan is kicking on.
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Re: couple of battery pack questions.

Post by Kenny'sID » Oct 31 2017 11:35pm

OK., thanks, and good deal on the cooling...surprising actually, and in this FL heat, a pleasant surprise at that.

I just got my XT60 connectors to convert this charger, and topped these packs off/just now testing them. Two finish charging @ 39.7V and 40.4V, the other 10 are between 41.6 and 41.8, or just fine. Are the first two packs I mention OK, or is there a problem with them? Figure I'd better ask before I contact the seller an make a fool out of myself.

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Re: couple of battery pack questions.

Post by wturber » Nov 01 2017 1:49pm

Kenny'sID wrote:OK., thanks, and good deal on the cooling...surprising actually, and in this FL heat, a pleasant surprise at that.

I just got my XT60 connectors to convert this charger, and topped these packs off/just now testing them. Two finish charging @ 39.7V and 40.4V, the other 10 are between 41.6 and 41.8, or just fine. Are the first two packs I mention OK, or is there a problem with them? Figure I'd better ask before I contact the seller an make a fool out of myself.
They should all be doing close to 42V if your charger is doing its job right.
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Iron Horse 3.0 hardtail - 48V / 1000W / 470rpm generic Chinese DD Hub motor (ebay)
8 x 36v 4.3ah 10s 2P battery packs - 1500W 30A DC Boost Converter delivers 54v and about 1000 watts peak
53T/42T Sakae Road cranks - 30mph+ on flats
viewtopic.php?f=2&t=90369

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Re: couple of battery pack questions.

Post by docw009 » Nov 01 2017 3:41pm

Kenny'sID wrote:OK., thanks, and good deal on the cooling...surprising actually, and in this FL heat, a pleasant surprise at that.

I just got my XT60 connectors to convert this charger, and topped these packs off/just now testing them. Two finish charging @ 39.7V and 40.4V, the other 10 are between 41.6 and 41.8, or just fine. Are the first two packs I mention OK, or is there a problem with them? Figure I'd better ask before I contact the seller an make a fool out of myself.
Following this thread with some interest, as I also have some packs from ebay seller alarmhookup. I agree with wturber. If your charger (don't know what you are using) is working consistently, all the packs should max out at the same voltage. Those first two are way off. See if you can work an exchange. You're off a whole volt or more at full charge, which means a problem battery.

For example, one of my batteries had a black burn spot on the XT60 connector, so I knew it got shorted out or had been previously used a lot. That same battery also was my lowest capacity unit. I opened it up last week to measure the cell groups. One of them only charged to 4.0 volt, instead of 4.2 like the rest. Weak cell. Explains the lower capacity. I was taking this battery apart anyway to get some individual cells, so I was OK with that.

BTW, I use these in undemanding applications, mostly as a single pack on a 250W motor with 10A controller. I have paralleled them up to run a 25A controller, but think they will last longer pushing lower current.

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Re: couple of battery pack questions.

Post by Kenny'sID » Nov 01 2017 4:38pm

Thanks much to both if you. I had a feeling, even being off just that much was not good news but as to knowing for sure, no idea. I did contact the seller several hours ago, heard nothing back yet. Actually 2 bad ones is pretty bad odds out of 10...any one know if this is a common problem with these? If this happens often, it could put a damper on the "good deal" factor, but we'll see how the seller handles it. I sent a video since these are somewhat pricey so...we'll see. Oh, I did consider that, but no reason to believe the charger isn't doing it's job.

Got the converter in...there was either a hiccup in the online tracking or something, but anyway, the converter has damage. He shipped it in a bag in a bag, and I kind a cringed when I first grabbed it, and sure nuff, a problem. I'll include a pic and it's the blue block, about the width of my pinkies nail, with an adjustment atop it. It appears to be held by one connection, the other 3 connections sticking out of the board.

I'm editing out the question about using the SLA bike battery for starting my car, I'm almost sure it wouldn't be a problem, but turns out my car battery is ok...don't ask, I feel stupid enough already. :)

Thanks again,
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Re: couple of battery pack questions.

Post by Kenny'sID » Nov 01 2017 5:04pm

Here 's what the battery pack seller replied...is he BS'n me? I mean why set a BMS to stop charging at 39.7V? Also Not sure if you all have seen the YT videos, but the fellow who did 2 vids on these, tested them for a balancer in the BMS, and his tests showed the LG packs don't have balancers at all. Or so he says.

New message from: alarmhookup Top Rated Seller

That's weird because each cell is 4.2v fully charged so if it was a bad cell then most likely it would only charge to 37.8v or less. I think the BMS on those 2 packs have different over voltage protections built in. Technically 4.1v per cell should be the max charge. Charging to 4.1 instead of 4.2v has shown to almost double the life cycles. So the BMS on those 2 packs is probably set to a new life extension setting. Maybe the Version of the BMS is newer and those settings are just a volt less. If you parallel them all together the battery packs should balance at the slightly lower voltage and the overall life of the battery should be extended.

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Re: couple of battery pack questions.

Post by wturber » Nov 01 2017 7:38pm

Kenny'sID wrote:Here 's what the battery pack seller replied...is he BS'n me? I mean why set a BMS to stop charging at 39.7V? Also Not sure if you all have seen the YT videos, but the fellow who did 2 vids on these, tested them for a balancer in the BMS, and his tests showed the LG packs don't have balancers at all. Or so he says.

New message from: alarmhookup Top Rated Seller

That's weird because each cell is 4.2v fully charged so if it was a bad cell then most likely it would only charge to 37.8v or less. I think the BMS on those 2 packs have different over voltage protections built in. Technically 4.1v per cell should be the max charge. Charging to 4.1 instead of 4.2v has shown to almost double the life cycles. So the BMS on those 2 packs is probably set to a new life extension setting. Maybe the Version of the BMS is newer and those settings are just a volt less. If you parallel them all together the battery packs should balance at the slightly lower voltage and the overall life of the battery should be extended.
I'm no expert, but I'd call that BS. The cells are rated for 4.2 volts I can send you the spec sheet. That means a 10s pack should charge to 42v or within fractions of a volt of that. That is technically what the max charge is. Charging to 4.1 volts is a choice where users trade off capacity for longevity. The same goes for charging to 4.05 and 4.0 volts. But the cells shoulc be capable of charging to 4.2 volts if that's what you choose because that's what their specs call for. I have ten packs that do just that. I also had one clearly defective pack (way low voltage) that did not do that.

Also, if the actual max voltage for those packs was set for something lower that would mean that the amp hour rating he is advertising would not be accurate. He can't have it both ways. He can't sell the same thing and expect you to accept two significantly different things.

If you go online you will find instruction on how to test each bank of cells separately by metering through the BMS connector. There are YouTube videos showing this. If you do this, it is likely that you will be able to identify one or more banks of batteries that aren't being charged properly.

Others will know more, but I'd be interested to know what happens if you discharge one of these undercharging batteries to the point where the BMS cuts off the power and then recharge the pack. Does the max charge voltage change? Also, a different charger might apply a trickle charge longer which might give some cells a chance to reach full charge. This is one reason to not go with the least common denominator charger. A better charger might to a more sophisticated job of interpreting the voltages coming from a pack and hence do a better job of charging. A balance charger might even be able to bring the pack back into balance.
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Re: couple of battery pack questions.

Post by wturber » Nov 01 2017 7:49pm

Around the 14 minute mark of this thorough test, the reviewer shows how to access and test each individual 2P bank of one of these modules.

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Iron Horse 3.0 hardtail - 48V / 1000W / 470rpm generic Chinese DD Hub motor (ebay)
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Re: couple of battery pack questions.

Post by Kenny'sID » Nov 01 2017 10:52pm

I'm tending towards agreeing with you....BS.

Are you saying if I discharge it, the recharge might straighten it out?

You know, I hate to just come out and say it, but with the luck I have with so many sellers, I don't really have a problem doing so. It wouldn't surprise me if the returned bad packs end up right back in the "sell" pile until someone either doesn't check, checks an thinks it's no big deal or is simply too lazy to return them/whatever and someone ends up keeping them eventually.

How bout the part about it not mattering and them leveling out once all are joined to each other or whatever the details to that comment were? True or more BS? Isn't that like saying, forget the balancer, it doesn't matter if a cell varies or if a full pack varies in voltage?

Good point about the AH's as well. I may have seen that video, but either way, will check it out all depending on how I decide to go with this.

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Re: couple of battery pack questions.

Post by docw009 » Nov 02 2017 1:49pm

Any packs put in parallel with that 39 volter could discharge (depends on what the BMS is doing) to that voltage (a) wasting whatever charge you had put in and (b) perhaps put out some high currents between packs in the interim. To use it, you will have to keep it in parallel with good packs both for charge/discharge. That wastes the capacity of the better packs.

Running all the cells at 39 volts might lose .25 AH out of the 4.0 AH capability. It's not a lot and a single hoverboard user would never care, but it does add up if you run 2 or more in parallel for ebiking. It's .25AH for very pack you add.

In addition, there could be some early cell degradation which will drop that 39V battery even lower after some use. I think it is reasonable to tell him you will be exchanging those two packs. I'd be gracious and pay the return shipping.

There are folks on this forum who have posted about charging these things to 45 volts, ruining them, and they say they sent them back. It's gotta be tough for an ebay seller, as paypal/ebay put all the cards in the buyer's pocket. I sympathize, but in your case, you haven't done anything.

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Re: couple of battery pack questions.

Post by Kenny'sID » Nov 02 2017 3:51pm

Thanks Doc, in that case I'll likely be returning these. I left questions under the videos of the two youtubers that are testing these, and I'll give it another day or so, if I get no replies by then, off they go.

I sold houseplants on Ebay for about 5 yrs and when ebay got rough, I dumped them. It's rough on both buyers and seller, and there are plenty of good and bad of each, unfortunately ebay treats both fairly unfairly all depending on how they are balancing things at any given time, but never deals with it properly because it cost money they don't want to spend,... always been the way. I try to do the right thing, the reason I wanted to be sure, and now I get to deal with the converter seller I mentioned a post or so ago that shipped with no rigid packing, a potentiometer broke off and I'm stuck with, ordering another, wait forever, then do the work/time fixings it, none of which I bargained for, or just make him refund in full.

Sorry bout the rant, but I only want what was promised and paid for. lol, and things go wrong there way too often.

Thanks again, very helpful/understanding.

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Re: couple of battery pack questions.

Post by wturber » Nov 02 2017 4:01pm

Kenny'sID wrote:I'm tending towards agreeing with you....BS.

Are you saying if I discharge it, the recharge might straighten it out?
I may be talking out of my butt, but if there is no really faulty cells and the pack is simply a bit out of balance, then maybe a long slow recharge could help. The best thing would be to put the pack on a balance charger and see if all the cell banks could be brought into balance and if they stay there. But while interesting, I'm not sure that this is something you should be responsible to do.
Kenny'sID wrote: You know, I hate to just come out and say it, but with the luck I have with so many sellers, I don't really have a problem doing so. It wouldn't surprise me if the returned bad packs end up right back in the "sell" pile until someone either doesn't check, checks an thinks it's no big deal or is simply too lazy to return them/whatever and someone ends up keeping them eventually.
Maybe. But I can tell you that with the one bad pack I had, this guy did not request that I send it back. His solution was to credit me $20 for the pack since I had paid $200 for 10 of them (I have no idea how I happened into that deal. I suspect he made a listing with a typo in the price.) Given the super deal I had on 10, I accepted that and simply ordered another pack using the $20 credit and paying the extra $15. I was OK losing $15 given that I'd saved $50 on the original purchase.
Kenny'sID wrote: How bout the part about it not mattering and them leveling out once all are joined to each other or whatever the details to that comment were? True or more BS? Isn't that like saying, forget the balancer, it doesn't matter if a cell varies or if a full pack varies in voltage?
My understanding is that to the extent that a leveling out occurs, it tends to do so toward the lowest power pack as docw009 described. That's why there are balancing BMS electronics and why there are balancing chargers. An unbalance cell or bank of cells in a parallel pack can eventually wreck havoc on the entire assembly. That's why I advocated you getting a balance charger. This could still happen down the road with any of the packs. BTW, the fellow who tested one of these packs in that YouTube video concluded that the BMS in these packs provide protection only. They do not balance the cell banks.
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Iron Horse 3.0 hardtail - 48V / 1000W / 470rpm generic Chinese DD Hub motor (ebay)
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Re: couple of battery pack questions.

Post by Kenny'sID » Nov 02 2017 4:32pm

I agree, interesting, and I would actually try that if I had the balance charger, something I may get soon. I actually got a wild hair and built a cheap bike, rear wheel hub motor with new SLA's and new trailer to try to sell, so I need to hold off to see just how much I'm going to remain into these things before I spend much more. Turns out there are a lot on Craig's list going cheap but this one is all new so, we shall see. Be nice to even get a small income form this...I enjoy it.

Thanks for that, I meant to ask how he dealt with your bad pack.

And wreaking havoc is not something I want right now :) so...good to know that. I've pretty well decided to go for replacement or however we work it out.

Appreciate it.

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Re: couple of battery pack questions.

Post by Kenny'sID » Nov 02 2017 4:39pm

On the broke in shipment converter, I did easily find the part... a whopping .70 for 5 if I don't mind waiting, and cheap even from Amazon and get it fairly fast.

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Re: couple of battery pack questions.

Post by Kenny'sID » Nov 04 2017 10:38am

Didn't mention where I got the info, but told the seller the advice I got was to get replacement and this is what I got back.

Which ones were they the light pink lg cells or the ones in the picture?

I smell the impending string along....so typical. That is unless someone can tell me how the answer to that is going to have any bearing on the return?

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Re: couple of battery pack questions.

Post by docw009 » Nov 04 2017 12:50pm

The color of the cell could tell the seller which ones to send you as replacements, or it also could alert him as to whether you opened the packs.

I have bought six packs. Four were fully shrink wrapped and no way to tell the cell color. Two were wrapped only in green paper and the cell color was visible. Might as well tell him what you got. If you cannot tell because they're fully wrapped, say so.

BTW, one of those packs should have been pink LG, but all of them were blue Samsungs.

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Re: couple of battery pack questions.

Post by wturber » Nov 04 2017 1:16pm

Kenny'sID wrote:Didn't mention where I got the info, but told the seller the advice I got was to get replacement and this is what I got back.

Which ones were they the light pink lg cells or the ones in the picture?

I smell the impending string along....so typical. That is unless someone can tell me how the answer to that is going to have any bearing on the return?
Go back and check your ordered. Did he send what you ordered? That may be all he's doing. Verifying he sent the right items.
I always ordered LG cells as stated in the title of the item I ordered. Almost all of the testing I found - and the one excellent test - were on the LG cells.
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Iron Horse 3.0 hardtail - 48V / 1000W / 470rpm generic Chinese DD Hub motor (ebay)
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Re: couple of battery pack questions.

Post by x.l.r.8 » Nov 04 2017 4:27pm

On the lg batteries, I had 2 packs that were dark purple, the rest were light. I had one pack that had 4 cells at 2.9, I charged them all to the same voltage, discharged it as a 4v pack re charged as a 4v pack and now they all behave the same. I kept them in a separate string on a battery just in case they miss behave later on. I think you might simply ask him why he asked rather than come here trying to second guess his intentions, with that many packs I’m sure he expects some returns, especially when given so many people are probing and playing with them.
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Re: couple of battery pack questions.

Post by Kenny'sID » Nov 04 2017 11:20pm

Yes, the order was correct. I had already discussed with him that I had 8 good ones and 2 bad so..

Thank for the info on possibly getting those 2 packs to act right, I can always add them to what I have/and that way they will be separate just in case. Also, if this goes ok, I'd really like to get 10 more so, maybe they'll be plenty of opportunity to use those to if I can get them right.

Second guessing? I do believe I asked why he would ask so I'd know if he was stringing me along for sure..hope that's ok : As far as my suspicions, as many bad sellers as I've run into, that was a very mild comment and somewhat a residual of his B'Sn me from the start so, no remorse here. :) And thanks for your comments, hope it was a pretty innocent/necessary comment...well see how it goes.

I just finished wiring/shrink wrapping the 8 good ones. I was going to do 2x5 packs, then I realized one would do me no real good on it's own, and since ten would be to heavy, I went with 8. It's pretty long but not real heavy. Actually I'm making excuses, 10 would have been best, but I ordered my shrink wrap wrong and I'm not waiting another two weeks for more. So between that and the battery delay, 8 it is. That and I'm itching to try the batteries on my trike with a smaller engine/new trailer, and I don't like the SLA's at all.

I should probably be concerned about balancing these and not wrapped them, but so many people are saying they stay pretty will in balance...not sure what to do there if anything. Maybe someone here already commented on it, I don't remember.

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Re: couple of battery pack questions.

Post by wturber » Nov 06 2017 2:04am

Kenny'sID wrote: I just finished wiring/shrink wrapping the 8 good ones. I was going to do 2x5 packs, then I realized one would do me no real good on it's own, and since ten would be to heavy, I went with 8. It's pretty long but not real heavy. Actually I'm making excuses, 10 would have been best, but I ordered my shrink wrap wrong and I'm not waiting another two weeks for more. So between that and the battery delay, 8 it is. That and I'm itching to try the batteries on my trike with a smaller engine/new trailer, and I don't like the SLA's at all.

I should probably be concerned about balancing these and not wrapped them, but so many people are saying they stay pretty will in balance...not sure what to do there if anything. Maybe someone here already commented on it, I don't remember.
I've been running 7 packs in parallel. I've been too busy at work to build the boxes I'd like, but when I get time, my plan is to have two packs of four . I plan on mounting them as saddlebag/panniers on the side of the rack. That will drop the center of gravity a bit and leave the rack open for carrying other stuff when needed.

I plan on keeping the other two packs as spares.

As for balancing, I charged my packs last night and checked them this morning. All packs had 40.8v (charge was set to 41v). I set them up to charge again, and the combined voltage bumped to 40.9v. So there probably is some slight imbalance and the packs probably equalized down to the lowest voltage pack overnight. So while not perfectly in balance, they seem to be doing pretty well as I approach 1000 miles on the group.
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Iron Horse 3.0 hardtail - 48V / 1000W / 470rpm generic Chinese DD Hub motor (ebay)
8 x 36v 4.3ah 10s 2P battery packs - 1500W 30A DC Boost Converter delivers 54v and about 1000 watts peak
53T/42T Sakae Road cranks - 30mph+ on flats
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Re: couple of battery pack questions.

Post by Kenny'sID » Nov 06 2017 11:09am

Good idea on using the saddlebags. I always though that would work well with the led acids with the center of gravity being a huge issue...hey, get them low enough and the bike would almost stand up on it's own :). But in the end, the SLA battery weight for these 1000w bikes are just to heavy for the bike. The pannier bag I use on mine works well with both the 2 and fits nicely under the seat and slightly back of the 4 wheeler so that might be the way to go for me since I have to move them from bike to bike. That'll put them mid wheel or lower. Its a tough saddlebag.

1000 mi is good. That's kind of what I would have expected with the balancing, so for now, I'm not going to let it be a concern. At worse one can do as in the video and balance the individual cells, if necessary, every couple thousand miles or so.

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Re: couple of battery pack questions.

Post by Kenny'sID » Nov 06 2017 1:35pm

I may need to start another thread, or even go to a different site but I'll give this a shot here first.

I need to order the broken potentiometer for my converter. I can solder it to the board, no problem, but that's about as far as my knowledge goes in this area.

I bought these, no big loss if they are wrong ....

https://www.ebay.com/itm/5pcs-3296W-503 ... SwUuRZ2tox

And then I saw a bunch more of different ohm values, meaning I probably ordered the wrong ones unless I got lucky.

Question, how do I tell what ohms mine is? What I could read on the side of the ones at the link are the same as mine..at least the larger letters, but I see now I have an "M 104" and a "101 T" stamped on the top of mine. Not sure if that's any help or not.

Can any of you help me get the right part if I don't have it already?

Kenny'sID   100 W

100 W
Posts: 141
Joined: Jun 11 2016 7:36am

Re: couple of battery pack questions.

Post by Kenny'sID » Dec 26 2017 8:32pm

wturber, I replaced the broken pot, and have it set to 51V output. I don't recall all we discussed, but I do recall trying not to overload myself so I could get some of it behind me before I frustrated myself with to much info. If the info is here already I can try to find it, but would running this up to 51V output be ok? Don't recall the exact specs but I get te idea that's fine. I know some run their 48V on a 52V battery, and I figure since I have the option might as well do that or close.

I had to fiddle with all 3 pots before I found the right one, so I guess I should ask what the other 2 are for and where they should be set before I try this.

Also, I'm assuming 10guage wire is fine for this, but wonder how you ran all the battery output wires together so they could be routed to the converter? I can probably come up with something but since you've done it, and if you'd please tell me how, I might go that route all depending on what I have here at home to work with (no more China orders, too time consuming :))

And the fan, it's automatic...right? I recall it came up and seem to remember you said it hardly came on meaning it is, but don't remember for sure.

Can't think of anything else at the moment, but when this is settled, I'll look for other suggestions you made.

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wturber   100 kW

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Re: couple of battery pack questions.

Post by wturber » Dec 27 2017 2:45pm

I run mine at 54v, which is the approximate voltage of a fully charged 48v Li-Ion battery pack. That should be safe for any 48v system. Your 51v should be fine too. There is probably no significant difference between using either.

The other two pots are for limiting current output and for setting the input voltage cuttoff.

I crammed all of the information I have on this converter into one document and posted a copy of it on one of the related threads. I'll look for that information tonight and re-post it in this thread.

Yes, the fan is automatic. I heard mine come on once. But it turned off before I actually had a chance to see it running. My heatsink never gets warm. My guess is that the booster is pretty efficient at converting the 36v output to 54v. Other combinations may not be as efficient and may create a greater need for the fan. Also, mine gets pretty good airflow. So the fan may be more important in installations with less natural airflow.
"Commuter - DC Booster"
Iron Horse 3.0 hardtail - 48V / 1000W / 470rpm generic Chinese DD Hub motor (ebay)
8 x 36v 4.3ah 10s 2P battery packs - 1500W 30A DC Boost Converter delivers 54v and about 1000 watts peak
53T/42T Sakae Road cranks - 30mph+ on flats
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