Looking for approval/advice for my LiPo Noob purchase list

[Kin]

Hi. For a while I have been putting together my plan for a 20" folder. I don't have a motor yet (Blaahhh), but getting Lyens controller in recently (9fet 72v set to 48v) convinced me that I really might want to push for getting all the components now, even though I'm a bit concerned now with actually spending the money . That said, for my folder bike I think i decided I want to get Lipo for form factor and weight. After asking questions and reading on forums I think I know what I want to do, 12s,1p or 2p (I have very little range requirements [2-6mi] right now so the 1p 2p $100 difference is up in the air. I really know I should get 2p so I don't run down the batteries and because ultimately I'll probably want 12s2p or even 3p for more range. 5ahr packs].
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That aside, I'll split up my thread into what I'm considering buying as components of my LiPo system. I'll edit things as I get feedback
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BALANCE CHARGERS:
I will not be buying a balancer right now! I have access to a work shop that has some RC chargers that I will be using to balance the pack for the start. In the future, I am investigating into an microprocessor charger that I have at home (In MA, i am in NC) that might be able to charge LiPo, or else, I will get a mediocre cell balancer and hope my cells aren't needing frequent balancing.
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CHARGER:
I intend on getting a 48v meanwell. Here are some ebay links. Are these legit suppliers / reasonable prices?

*update*. I ended up getting the 50% cheaper offbrand Meanwell. Hopefully that won't die too quickly..

http://cgi.ebay.com/MW-48V-DC-7-3A-350-4W-Meanwell-Switching-Power-Supply-/350452131223?pt=LH_DefaultDomain_0&hash=item5198932597#ht_3806wt_957

http://cgi.ebay.com/Meanwell-S-350-W-48V-DC-7A-SMPS-switching-power-supply-/130420159644?pt=LH_DefaultDomain_0&hash=item1e5da5b49c#ht_762wt_932

[They're about $65-75 dollars. I can't tell if either are "genuine" or not.]

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PACKS:
I think I've heard talk about somewhat better packs and a bit cheaper before, but I guess there are no good sales right now.

5ah 6s Zippy 20c http://www.hobbyking.com/hobbyking/store/uh_viewItem.asp?idProduct=16793
*Update* ^ I did purchase 2 of these blocks. In the next month I think I will get another 2, but because 5ahr is very little.

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LVC / Warning System

Just one of these for each of my packs? http://www.hobbyking.com/hobbyking/store/uh_viewItem.asp?idproduct=7227
^*Update: I am considering cell log8s per neptronix. They're a bit costly though ($50 for $200 of batteries :S)

OR should I simply get this http://www.hobbyking.com/hobbyking/store/uh_viewItem.asp?idproduct=10328 and check before and after any substantially drained ride?

*Update* Have not decided on a LVC system.. It would be nice if I could just set conservative low voltage cutoff on my Lyen controller and go from there, but I assume sag makes using the the controller as the cutoff difficult.
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CONNECTIONS:
Here I really do not what I'm doing. There's actually not much talk in the LiPo noob threads about what connectors will be needed for a system. I think it shouldn't be crazy since I'm just going to run two or four 6s packs in series. I'd like to make sure I get the right stuff so that I don't show up with all the parts finally and still have no way to connect my pack.
*I snagged some balance cable extensions, silicon 10awg wires, 1m red and black, and a pack of 4mm bullet connectors.


Now I still need....My 9C motor. I originally really wanted to buy from Ebike.Ca because they seemed like a great company, but I might end up buying from Cycle9 [Well, for one, they have 20" in stock >.<, but also because of shipping costs].

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For anyone who was willing to read this and check it out I really appreciate it. I'm (quite noticeably) new to LiPo and Ebikes, but I think I can learn.. For curiosity's reference, I plan on getting a 9C and this is for my beloved 20" folder http://www.citizenbike.com/catalog.asp?product_category_id=1&product_id=24
No shocks, this'll be on good road use.

Long term summer goals: Figure out my pedal gearing situation (probably get a large chainring).

 

[neptronix]

Packs: 20C is good enough for hubmotor use, 15C is good enough if you are paralleling two or more packs, and it is also the cheapest, smallest, and lightest lipo you can get.

For a 9FET you're going to be drawing 25-40 amps.. lipos will get hot under these conditions and sag, definitely recommend going with a 10AH setup for that kind of amp draw because you will be beating on the batteries otherwise. ( read my build thread for more info )

Connectors: I use 4mm bullet connectors ( with the red sheath ) from hobbyking as they are what comes stock with the lower C rate packs. Just my suggestion.. you really can use anything..

Charger: i don't know about meanwells but i really think you should buy a balancing charger and use that at first to get familiar with lipo... and also to test your lipo to separate the occasional dead cell pack.
The battery Medic can be helpful as it can do balancing and show you what's going on with your cells though.

LVC: Forget those stupid buzzers, their LVC is very low, get a pair of cellog 8s's, they have a settable Low and high volt *per cell* alarm function.

Please read about the dangers of lipo before you proceed. If you are very new to this i hope you have done your research.

 

[AussieJester]

Buy the highest 'C' rate battery you can afford, decide
which you want 2 or 4 packs and how they will be connected to determine you required voltage. ... I would purchase a meanwel
power supply from ebay for sure (and did several times LoL) and use this for charging your packs
Plug your packs directly into the meanwel don't charge to far over 4.15v and
stay above 3.2v a cell on the discharge (I set meanwel to say 49.8v for bulk charging my 44v
pack) ..the packs should last for over 1000cycles :wink: Balance packs with rc charger at work and/or battery
medic when needed...which is hardly ever you will find if you treat them right.
Buy a couple of meters of 8 or 10ga wire from hobbycity when you get the packs along with a few dozen
4mm bullet connectorstoo suit, to build a simple wiring harness to connect all the packs. With this method you can
charge extremely quickly and cheaply ... . Best of Luck

KiM

 

[neptronix]

I don't agree with the high C rate thing.

AussieJester, hub motors have miniscule amp draw compared to your RC motors.

I can pull 43amps constant out of 2p ( 10ah ) 20C Zippys that are almost a year old and they sag a mere 1 volt out of 40v.. and never get above room temperature. That's about a 4C load..

Higher C batteries are more expensive, larger, and heavier so why bother with them if you don't need em?

 

[Kin]

Hey Neptronix. I think I will switch out my LVC for the cell logs per your suggestion...but, if possible, is there anything cheaper that will do? http://www.hobbyking.com/hobbyking/store/uh_viewItem.asp?idProduct=10952 it looks like I will need 4 of them...which is actually a considerable cost. Mentioning it, I think I saw more of those on ES so I don't know why I chose the other though [probably cost]. I'll probably go for the 10ah, (tho my controller is limited to 25a for the time being so it'd mostly be for range and to take care of batts]. So the connectors, then, I'll take a look to find out if there are enough that come with the packs (i didn't realize any would come with the packs). I can just get the wire with the pack purchase as AussieJester recommended.

Is the battery medic a sufficient balancer when it comes to occasional balancing? It doesn't look like it has a power supply, so I assume it must discharge to the lowest cell voltage. I'm happy with it if it can serve that purpose.

I have been doing a lot of research [so many hours on ES and elsewhere] and I'm not going to run these to any extreme on discharge precisely out of respect for their fireball venting. I hopefully can take care of things once I've figured out how to use them. In the long run I will also have a CA to monitor battery trends [and for normal CA use].

Aussiejester, thanks for your response. Do you have any recommended ebay sellers? I put up two links I found, I don't know if they're any good [look good from general ebay experience though - nothing super sketchy]. When you say "how they will be connected", that's one of my questions with connectors. I can easily solder 8 or 10ga wire [does it matter if I choose the thinner one?], apparently with some standard bullet connectors that come with the packs. I'm not sure how I would go about making the parallel connector aspect, but it would be easier to have some sort of premade Y-like cable that could be dependable). Is there something people buy built or does everyone just make it?

 

[mud2005]

I reccommend the nano-tech for sure.

you can get 6AH packs and they are of the highest quality.

even if you're not using them to their fullest potential, they are worth the extra IMO

 

[Kin]

I reccommend the nano-tech for sure.
you can get 6AH packs and they are of the highest quality.
even if you're not using them to their fullest potential, they are worth the extra IMO

The nanotech seem cool [really cool. Jesus. 90C??? That's a capacitor, not a battery]. ...but they are pushing costs higher a fairly substantial amount.. I really don't think I can justify them [almost 2x]

 

[newb]

I have a couple folders and i would make the suggestion of looking at the Downtube line of bikes (like the 9FS), that is if you already haven't purchased the other. I have a 350watt geared motor on it as its lighter (weight is an issue for me - only weighs 7lbs, 1/2 of the 9c), more efficient and freewheels. At 12s 2p which is 1 of 2 configurations i run (also 18s 2p) on a 20" wheel im running 22mph an @ 18s 31mph. At 30mph on a folder the full suspension is a must for me. if ur sticking with ur original bike idea then i would recommended a suspension seat post like the thudbuster which is kinda spendy or suntour ncx which is a third the price but somewhat similar design to smoothen out the roads. as far as gears go, i have a 53t chainring and run 11-28t 7 spd frwhl (shimano mf-hg50 - also avaialbe in 11-34t) and this allows to to keep up even at high speeds. hope this helps

oh and if u contact progressiverc.com they have some wiring premade - http://www.progressiverc.com/index.php/cables/parallel-cables.html

 

[Kin]

Cool. The folder I'm using has an upgraded (relatively subtle, still a bit embarrassing) "luxury" seat. I figure, I'm young, and not going distances, so I can survive no suspension. I've been using the bike for 4 months now as a regular bike between campuses back and forth twice or more every day. I really like my bike as it stands. My long term concerns are not damaging my bike, so if I start worrying about over stressing the bike, and I end up ebiking a lot, then I'll look into buying a 20" bike with suspension. Thanks for the suggestions for the wiring as well. I'm not sure if I will use them, I guess, this isn't as complicated as I make it out to be. Once I have the parts I should be able to figure out connection solutions.

 

[neptronix]

Hey Neptronix. I think I will switch out my LVC for the cell logs per your suggestion...but, if possible, is there anything cheaper that will do? http://www.hobbyking.com/hobbyking/store/uh_viewItem.asp?idProduct=10952 it looks like I will need 4 of them...which is actually a considerable cost.

Run your balance cables in parallel along with the pack, you will only need two then

That will also allow the two cell groups to balance each other out. The overall pack will stay more balanced that way.
If you are only going to do 2p ( 10ah ), progressiveRC sells nice parallel balance lead doohickies.

Is the battery medic a sufficient balancer when it comes to occasional balancing? It doesn't look like it has a power supply, so I assume it must discharge to the lowest cell voltage. I'm happy with it if it can serve that purpose.

I don't have any experience with them but that's generally what people use for high voltage packs when no such balancer exists. IE if you are charging a 15S setup, just plop 3 of those on there along with your bulk charger and set it to discharge past a certain voltage so that the cells don't get disbalanced. The setup works similarly then as a balance charger ( although it will have far less capabilities overall )

I have been doing a lot of research [so many hours on ES and elsewhere] and I'm not going to run these to any extreme on discharge precisely out of respect for their fireball venting. I hopefully can take care of things once I've figured out how to use them. In the long run I will also have a CA to monitor battery trends [and for normal CA use].

As long as you keep discharge above 3.6v per cell and charge up to 4.2v, they will live a long and productive life .. balance charging is not necessary every time, but you will need to check the balance here and there.

 

[neptronix]

BTW as for the parallel and serial connectors, you need to make your own. That's why i bought a buttload of the 4mm bullet connectors. But i didn't buy the turnigy wire, i am using copper from radioshack instead.

 

[dogman dan]

Buy the best c rate you can afford. But if the cheap stuff is what you can afford then get that.

Why? Because the batteries may be used on something else later for one. Because they will still perform better with less strain on them if you buy the best you can, even if you are only using 5c out of em. Even though voltage sag won't be severe, the less you have the better you'll be grinning.

 

[wineboyrider]

I don't agree with the high C rate thing.

AussieJester, hub motors have miniscule amp draw compared to your RC motors.

I can pull 43amps constant out of 2p ( 10ah ) 20C Zippys that are almost a year old and they sag a mere 1 volt out of 40v.. and never get above room temperature. That's about a 4C load..

Higher C batteries are more expensive, larger, and heavier so why bother with them if you don't need em?

I say buy the best you can afford, but definitely stay away from the 15c zippy packs I have had numerous cells that didn't last on smaller 5s 4400mah packs. Granted they were small packs and I was pushing them hard, but they don't seem to last. The frustration is not worth it for sub 20c packs IMHO. 25c seems to be the sweet spot for lipo on ebike commuters tho.

 

[Partycat]

Since I would consider the Zippy/Turnigy to be roughly the same sort of product, I didn't differentiate between the two much. I ran some numbers yesterday and found that to do 14s with 5/2 packs, that the Zippy 30C 8000mAh's were cheaper per amp-hour by like 5 bucks than the 5000mAh packs. Then you're looking at three in parallel for 24Ah versus 4 for 20Ah. More capacity, less wiring. Cost a bit more but it would seem to be worth it, other than the larger hit you would take on a failed component.

 

[AussieJester]

I don't agree with the high C rate thing.

AussieJester, hub motors have miniscule amp draw compared to your RC motors.

I can pull 43amps constant out of 2p ( 10ah ) 20C Zippys that are almost a year old and they sag a mere 1 volt out of 40v.. and never get above room temperature. That's about a 4C load..

Higher C batteries are more expensive, larger, and heavier so why bother with them if you don't need em?

Lower C rate lipo packs are made from lower quality
cells that didn't make the cut for higher C rate packs, buying the higher
C rate packs you get better quality cells, higher chance of getting the
1000 plus cycles and no dead or weak cells in the packs...

KiM

 

[maris]

Lower C rate lipo packs are made from lower quality
cells

If is so, why their weight is less then more C rate batteries?

 

[Kin]

^Very good point. The lower weight does suggest the cathode / something is intrinsically different. I did avoid the "b-grade cells". Somehow, I imagine the higher quality cells have better QC just because they're more expensive products and it's more important for them, but I ended up settling on the 20C Zippies as a cost compromise, I really can't afford the higher C ones right now.

 

[aaronski]

My setup is:
18s turngy 20c pack. 2.65 ah -
Limited to 60 amps
5 mile range
3v sag at 3000w
About 50 cycles so far.
Puffed 2 cells by hillclimbing till I hit 2.8v per cell. They unpuffed when the cooled off though.

Riding slower, I can get 2.6 ah from the pack, at 4.2v to 3.2 v

I'm with nephronix, cheaper cells do fine.