What configuration of LiPo do I need for 48, 60, 72V?

[az crusin]

Getting closer on starting my eBike build. I will probably start off with a MAC 8T or 10T from cellman and eventually try a DD motor as well. I'd like to use LiPo batteries. I read through the wiki on LiPo batteries and other post, still have questions on what config I should use.

48V seems safe to use on these motors but I'd like to use 60V or 72V in the future, not necessarily on these MAC motors but maybe on a DD. Is there a configuration of LiPo's that I could build that would equal 48V and be able to easily add to it to make 60 or 72V? Or should I config 72V now and use a CA to limit, if thats possible.

I want a minium of 10Ah. 10Ah is "probably" enough, I'd like to keep the pack small and light. But I'd like to take in consideration of possibly upgrading it to 15/20Ah in the future "if" it's not too much trouble.

Oh and also if someone could recommend a charger and/or balancer if needed for what you recommend. Budget is not too much of a concern.

 

[gensem]

Easier path would be two 6s in serie with 4 parallel each 12s4p (44v 20ah) that could easily be used as four 6s in serie with 2 parallel each 24s2p (88v 10ah)
But be aware your range at 88v ll be minimal.

 

[Drunkskunk]

5S packs are what I run. 37V for 10S is close enough to 36v. or stack 15s for 55.5V. Better than 48v and its peak charged voltage is 63volts, which is the peak most "48" volt controllers can run. 20S is 74 volts.

 

[neptronix]

I like 5S packs because i can perma-series them and charge the suckers with the iCharger 1010b+...
this is of course before the hyperion 14S capable charger came out

The real question.. is since you can choose a winding of a MAC motor to get whatever top speed you like ( practically ).. how fast do you want to go?

 

[az crusin]

I'm looking for 30mph minimum. Maybe more but hard to say since the fastest I've went is 20mph. I know I want faster than 20mph, just not sure how much. That's why I want some flexibility on how I build these LiPo's. If 48V gets me 30mph and that's fast enough then I'll be done with it. If not then I'd like to add some more till I get 60V. Or maybe 72V.

 

[John in CR]

I like 20s when using 3.7V nominal cells (LiMN and RC Lipo in my case). The reason is that it matches perfectly with 23s LiFePo4 (my A123 packs). I can parallel the packs of 2 different chemistries and I believe it's actually better than either one separate, and I can bulk charge them to an 83V cutoff with the same charger, even in parallel, and it's nice and conservative for both. No other combination of series count for either works as well without going much higher in voltage than these 74V packs.

 

[dogman dan]

For "lipo" that is Hobby king type, 10s is typically accepted as 36v nominal. 20s is also accepted as 72v nominal. 18s might be a tad higher than 60v nominal, but close enough for me. Likely by then you are using a 72v controller anyway.

48v is where things get vague. Many are calling thier 12s pack 48v. I call it 44v. But since it sags so much less than a 2c cell, your running voltage under load may not be a full 4v less than a pingbattery or such. Looking at the other end, since your controller may have 63v capacitors in it, you may not want to run 15s.

12s charges to about 50v. 14s charges to about 59v. 15s charges to about 63v. Pingbattery 16s lifepo4 charges to about 60v, and many other lifepo4 charges to about 58v.

So I call 14s HK lipo the closest to the voltage of my ping 48v lifepo4. But do I run 14s lipo? No. 12s 44v lipo works fine, and is much easier to deal with using sets of 6s lipos.

Re the final top speed. A few motors are wound fast enough to reliably go 30 mph on a 48v pack, such as a 16s lifepo4 or 14s lipo. But you lose some snap leaving the stop sign, and may bog down on steeper hills unless you zap it with a lot more than 1000w.

The compromise I tend to like is a 72v controller. 18s or 20s battery, but keep the controller a bit wimpy. 72v 20 amps lyens controller I have gives a decent top speed of 35 mph and total 1500 watts that won't quickly melt a cheap dd motor.

Yes, it's half as fun as a 40 amp controller, but at 40 amps you are worrying about your motor. Cruising 30 mph with the 72v 20 amp controller, you are only worrying about enjoying the ride.

The other compromise I like a lot is just running on 12s. 25mph is enough for me 90% of the time. I'm old, and stopped hurrying around a good 10 years ago. Some bikes, like my longtail have a 20 mph top speed, and riding it I have lots of time to enjoy the majestic view of the nearby mountains. My travel routes do not require me to play dodge car.

So the 6s hk lipo pack might be just about perfect. Get a little bit more speed now, by running 44v if you are currently at 36v. Then later, run a dd motor at 18s for about 30 mph.

 

[hjns]

Is there a configuration of LiPo's that I could build that would equal 48V and be able to easily add to it to make 60 or 72V? Or should I config 72V now and use a CA to limit, if thats possible.

I want a minium of 10Ah. 10Ah is "probably" enough, I'd like to keep the pack small and light. But I'd like to take in consideration of possibly upgrading it to 15/20Ah in the future "if" it's not too much trouble.

Oh and also if someone could recommend a charger and/or balancer if needed for what you recommend. Budget is not too much of a concern.

In the end it is about what you are most comfortable with.

48V in lipo is probably 12S = 44.4V nominal and 50.4V hot of charger (HOC at 4.2V/cell).
3x 4S bricks in series. Main advantage of the 4S bricks is that these are the largest bricks with a hardcase around it. Adds weight, but decreases work regarding protecting the cells.
2x 6S in series. Main advantage is less cables. Larger bricks, and need something to protect them during the ride.
3x 5S in series (15S) = 55.5V nominal and 63V HOC. Higher than you specified, but some controllers may be able to handle it.

All of them can be expanded to your wishes; either increasing in voltage with steps of 4S, 5S, or 6S, or increasing in capacity by adding them in parallel, or both.

I choose 10S bricks of 4500mAh. Don't do it. If you want 20S or 30S, better stick to muliples of 5S or 6S. I use the iCharger 1010B with a lot of satisfaction. You may want to consider a charger that outputs data to the computer so that you can better monitor individual cells while charging / test discharging.

 

[az crusin]

Great info! I think I'm going to go for the 6S, 5000Ah, 25C (do I want the packs with a 25C rating?). To bad the compact batteries are out of stock at hobby king, I'll go with the regular ones.

Zippy or Turnigy? I think I see more people using Turnigy.

Where's a good place to get a charger? A good one. One that I can "set it and forget it", if that's possible with LiPo.

 

[Ykick]

(do I want the packs with a 25C rating?)

I think 20C is fine for commuting but 25C or higher won't hurt anything except, in some cases, maybe your wallet.

Zippy or Turnigy? I think I see more people using Turnigy.

I've gone back and forth about this for 2 years - used both brands daily over that time, I will give a slight advantage to Turnigy.

Where's a good place to get a charger? A good one. One that I can "set it and forget it", if that's possible with LiPo.

I like EPBuddy for chargers, power meters, cell logs, etc. if it's in stock you get it quick and if there's a warranty issue you ship it to Ohio, not China. Prices are very competitive IMO.

I suggest we should attempt to refer to Hobby King bricks as "RC Lipo". Luke has suggested this in the past and it's only 2 more letters to type in your posts but makes it pretty clear what Lipo you're talking about.

 

[dogman dan]

Yeah, seems we've been creating some confusion. RC lipo, or HK lipo if refering specificly to packs avaliable at HK.

12s RC lipo, is not 48v. it's just about halfway between 36v and 48v. But because of less sag, 12s will do for the average bear. Enough performance increase compared to 36v to take the sting out of moderately steep hills.

Turnigy if you can get it the same price as zippy. Never, ever, neverever order anything out of stock at HK! So zippy or turnigy may just be a matter of what you can get at that moment.

If in the USA, order from the USA warehouse stock.

Ep Buddy is a good vendor to buy various bits from, I chargers, meanwells, wire, connectors, etc. Not cheapest, but shipping in country is so much faster than HK can sometimes be.

 

[az crusin]

Thanks for letting me know about the "RC LiPo"

Just bought 8 packs of Turnigy 500Ah 6S 25C.

Now for the charger...I like the local Ep Buddy site. Which one of these chargers would work for me. http://epbuddy.com/index.php?main_page=index&cPath=17_1 What's the difference between these?

 

[motomech]

Since you went with 6S bricks you are deffinately going to want a Hyperion 1420i , which can charge up to 14S.
There are some long threads on that charger, search it and you can read about it.

 

[dogman dan]

Different strokes for different folks. One of the beauties of lipo is the flexibility of how you manage them. Millions of ways to do it, all right. Only when sparks fly are you wrong.

I want a hyperion myself, but still don't want to pay for one just now. I have been very happy using a Meanwell 350w, and two cheap 150w chargers. It works fine for me, because I refuse to leave lipo attached to a bike in my garage. My lipo is not used daily, so I store it in a much safer way, at my fireplace where fire belongs.

Another good approach, is the i charger and a meanwell. Then make a harness to paralell all your packs, or use a paraboard, and charge away.

See Icecube 57's for sale new thread for a great way to paralell packs for an on the bike, non balancing charge.

 

[Ykick]

Starting from scratch with 12S I'd probably go for the Hyperion 1420 too and EP Buddy doesn't seem to carry them. Bummer... Maybe call/email Dale and ask if he can get 'em?

I started with a small iCharger 106B+ and different combos of RC Lipo which eventually morphed into Meanwell bulk charge setups that have been in daily use for nearly 2 years. Nowadays, folks seem to lean towards BMS Alloy shell chargers for bulk charge setups and a small, cheap RC charger or BatteryMedic for maintenance, troubleshooting, etc.

I'd say the most important item to have starting out is an inline power meter. Outfit with connectors that allow you to use it when charging and on the bike until you understand your bike load. At that point you'll probably leave it on your bulk charger most of the time. The Turnigy brand and the version EP Buddy sells only go to 60V but that's fine for 12S-14S RC Lipo.

Connectors become a very important issue so be prepared to sort out the type and tools required that best works for you.

 

[dogman dan]

Yes, a wattmeter of some kind is pretty much mandatory if you are the bms. I tried low voltage beepers, but they only tell you you should have turned home 4 miles ago. But better than nada.

I ride with a CA, but rarely need it much since my fun ride routes are now known to be short enough to make it home. But it sure is worth it's weight in gold when I am blazing trail on new routes.

 

[az crusin]

I ordered the Hyperion 1420i charger today to charge the 24S2P RC LiPo's I ordered from HK the other day. I know I won't be able to charge it all at once unless I get a 2nd charger down the road, which I may do later.

So I know I need a power supply to power it. The Hyperion charger is rated at 550W, 24A. Looking at EP Buddy's Mean Well power supplies, they have a they have a 600W, 24A model. I'm guessing that would work? Is there a different power supply I should be thinking about? Other vendors? http://epbuddy.com/index.php?main_page=index&cPath=5

 

[Ykick]

I ordered the Hyperion 1420i charger today to charge the 24S2P RC LiPo's I ordered from HK the other day. I know I won't be able to charge it all at once unless I get a 2nd charger down the road, which I may do later.

So I know I need a power supply to power it. The Hyperion charger is rated at 550W, 24A. Looking at EP Buddy's Mean Well power supplies, they have a they have a 600W, 24A model. I'm guessing that would work? Is there a different power supply I should be thinking about? Other vendors? http://epbuddy.com/index.php?main_page=index&cPath=5

I think you mean the 600W 24V, 25A PS? This one should do the trick nicely!

http://epbuddy.com/index.php?main_page=product_info&cPath=5&products_id=232&zenid=memrarceu8crpn9npao8ceh106

Damn, 'sounds like you're putting a nice charger setup together! If you can, grab a power meter and maybe CellLog8S if you have a PC to run Logview? Really helpful to check cells in your pack under normal loads on the bike.