Zippy Flightmax / Turnigy lipo testing

[Hyena]

I ordered mine first

Only problem is that I ordered 8 6S 5000mah packs and that put me over the limit for EMS Express so I had to ship via the slow boat.

I HATE THE SLOW BOAT !

-methods

Mine shipped out today on the slow boat too. 7-45 days. urrrgh
Australia is closer to China that the US though, so hopefully mine arrives first

On a related lipo note, do you reckon one of these universal laptop chargers set to 21v would do the job for charging my 5S packs ? It's only 3-4 amps so it'd take like 10 hours to recharge 5S6P, but for under $15 delivered I thought it'd do to put a bit of charge back into the batteries while at work to save lugging around my "big" charger.

http://cgi.ebay.com.au/CAR-UNIVERSAL-LA ... 7C294%3A50

[methods]

The beauty of lipo is that you can charge it with anything so long as it is equal to or less than HVC.
Please be very careful to make sure that the open circuit (floating) voltage of that charger is <=21V.
If so, sure it will work.. but it will take forever

I have about 10 of those variable power supplies now and so I have all kinds of chargers:

12S 50.4V 10Ah pack -> 20A 2C 1KW charger (takes about 35 - 45 minutes)
24S 100.8V 10Ah pack -> 13A 1.3C 1.3KW charger (takes about an hour)

I am working on the dual supply monster
24S 100.8V 20Ah pack -> 30A 1.5C 3KW charger.
Will require the special 40A outlets I installed when I built my house

-methods

[Hyena]

sure it will work.. but it will take forever

Yeah that's cool, as I said it's only to partially charge while I'm at work. My commute burns about 5.5ah each way so that little top up for a few hours will enable me to do the return trip on my 60v10ah pack without stressing the batteries (and more importantly, me )

I am working on the dual supply monster
24S 100.8V 20Ah pack -> 30A 1.5C 3KW charger.
Will require the special 40A outlets I installed when I built my house

You know you're clinically mad when you build your house around the charging requirements for your electric bike projects

[Daniel828]

This post made me re-think my battery direction. I currently use 24s1p DeWalt lifepo4 in solderless power tubes. They
are out of buisness, besides it's an expensive route using DeWalt packs and then the work of taking them apart and reconfiguring into the power tubes.
I am thinking of buying some packs from Hobby City.I would probably buy 5 of the 5000mAh 4s1p packs. What charger would I have to buy?
I have a Mastech 30v20a cc-cv power supply that I use to charge my lifepo4 pack. Could I use that?
Thanks
--Dan

[Hyena]

Why 5 x 4S ? Assuming you want to run them all in series for a high speed short range 20S 5ah pack, 4x 5S would be slightly easier to wire up for parallel charging and balancing. If you can afford to drop a few volts easier still would be to run 3 x 6S packs as 18S

If your power supply is adjustable you could use it.
For charging 4S you'll want it set to 16.8v, 5S 21v and 6S 25.2v
You'll need a balancer too, I use this one and I think methods does too.
You can charge through that balancer up to 10 amps but if you're current charger puts out double that you'll have to just connect it to the balance taps of the batteries.

[methods]

I just checked my tracking...
My packs have been parked at the Customs facility in San Francisco since June 13th

I am fix'n to sneak down there tonight, climb in through the window, and get my lipo goodness

-methods

[ZapPat]

The beauty of lipo is that you can charge it with anything so long as it is equal to or less than HVC.
Please be very careful to make sure that the open circuit (floating) voltage of that charger is <=21V.
If so, sure it will work.. but it will take forever

Humm... and just hope that all your cells are very well balanced when not using any cell level monitoring while charging like this?

Personnaly I would only feel "OK" doing this if I set the charger's output float voltage to 4.1V times the number of cells, and not 4.2V per cell (so 20.5V for this example). I actually don't even charge up to 4.2V per cell normally anyways (even when balancing) just to extend the life of my pack. I may loose ~10% usable capacity but the pack's lifetime will be greatly extended.

But you have much more experience using these Lipo's than I do, Methods, so what I say here is just my opinion and a conservative one at that I guess.

I hope your customs thugs let you get your battery fix soon, 'cause I want to know what the internal resistance is for these cells before buying a bunch. JohnRH says they are physicaly identical to the 20C zippys despite HC's specs, so we hope they also perform as well too. My 15C zippy have about 10mohms Ri per cell, so I would hope that the 20C cells are around 7mohms maybe?

[johnrobholmes]

I just found that the pcb is slightly bigger on the turnigy packs. Otherwise the cells are identical. Even the 15c and 20c zippys are the same size, which is kinda strange. Normally higher drain packs will be bigger, unless they are all made to be 20c and the 15c are just the rejects.

[Daniel828]

Why 5 x 4S ? Assuming you want to run them all in series for a high speed short range 20S 5ah pack, 4x 5S would be slightly easier to wire up for parallel charging and balancing. If you can afford to drop a few volts easier still would be to run 3 x 6S packs as 18S

If your power supply is adjustable you could use it.
For charging 4S you'll want it set to 16.8v, 5S 21v and 6S 25.2v
You'll need a balancer too, I use this one and I think methods does too.
You can charge through that balancer up to 10 amps but if you're current charger puts out double that you'll have to just connect it to the balance taps of the batteries.

On the Hobby City site the batteries are identified as 4s1p or 5s1p...etc..I like the 4s1p option because the price seemed to be the best. So if I buy 5 packs it would come out to about 240 bucks plus shipping. Where do they ship from anyway? Would I have to go thru the "customs" hold up issues too?

The Mastech power supply has adjustable Volts and Current too.
Thanks for the input Hyena
--Dan

[methods]

Daniel - Check the site again, it is almost always better to buy the larger pack. Sometimes a 6S sells for only 3$ more than a 5S. If it is not a space/packaging constraint go with 6S packs and higher voltage

Zap - Of course you are right. Sometimes I forget my audience, but for me it is ASSUMED that whenever a Lipo pack is being charged it has a balancer attached. It is also assumed that whenever a big, scary lipo pack is being charged at >2C rates that cell level alarms are hooked up.

To anyone who is considering charging their lipo in "gangster" mode, if you dont do full-pack level balancing then you need to charicterize your pack and lower the HVC accordingly as pat suggested. If your next inclination is to ask how then... Dont bulk charge. Stick with something safer till you have a good feel for lipo.

These work very well.
I just bought another one.

http://www.hobbycity.com/hobbycity/store/uh_viewItem.asp?idProduct=9005

Parallel up all your cells at the CELL LEVEL and POWER LEAD LEVEL and balance charge with this.

Charging will now be much safer... BUT... The risk of screwing up while converting from series to parallel just went way up.

-methods

[Daniel828]

I'm trying to wrap my head around this. So bear with me please.
I would like to use my Mastech power supply, what BMS should I use?
Can I use the BM6 as a BMS? Or is this just a monitoring device?
I want to get my shopping list ready so I can order all the stuff I need at one time
--Dan

[methods]

The BM6 will only monitor cells, not balance them.
Most any other RC balancer will only do from 6 - 12 cells.

You want to buy one of Gary and Fechter's 24channel BMS kits.
Look in the battery section.

-methods

[Ypedal]

Friend of mine got 4 of these Zippy 5ah, 3 cell, " 8H 15-25C "

one of the packs had a 1v cell
2 of the packs were well ballanced... withina few mah
4th was way out of ballance.. 1000mah+ low on the middle cell..

I popped my volt meter probe wires on my charger and held them in place on the ballance plug to top off the low cell.. ( ballancer was taking way too long.. )

incredibly small tho and light... i likey !!

[Ypedal]

Will be used on this ! ( Ironically at 12v 20ah, 30w HID, talk about low C rate! )

Name of the game was small and light weight, was top priority, will be mounted to a Honda CRF450 motocross bike !

Talk about BRIGHT !!!! i want one of these for my ebike !

[Hyena]

I like the 4s1p option because the price seemed to be the best.

The new turnigys are $10 per cell across the board it seems - 4S is $39.95, 5S is $49.95 and 6S is $59.95

[liveforphysics]

Friend of mine got 4 of these Zippy 5ah, 3 cell, " 8H 15-25C "

one of the packs had a 1v cell
2 of the packs were well ballanced... withina few mah
4th was way out of ballance.. 1000mah+ low on the middle cell..

I popped my volt meter probe wires on my charger and held them in place on the ballance plug to top off the low cell.. ( ballancer was taking way too long.. )

incredibly small tho and light... i likey !!

If you get a cell in your pack that arives out of balance, all you need to do is email Hobbycity and tell them. They will send you a new pack. Any LiPo cell that has been to 1v is permanately damaged. Hobbycity provides amazingly good return support for its products.

[Daniel828]

Friend of mine got 4 of these Zippy 5ah, 3 cell, " 8H 15-25C "

one of the packs had a 1v cell
2 of the packs were well ballanced... withina few mah
4th was way out of ballance.. 1000mah+ low on the middle cell..

I popped my volt meter probe wires on my charger and held them in place on the ballance plug to top off the low cell.. ( ballancer was taking way too long.. )

incredibly small tho and light... i likey !!

What does the 8H stand for in "8H 15c-25C"?
Also, what did you use to determine the mAh of the packs?
Thanks
--Dan

[liveforphysics]

The capacity readings on an un-cycled pack are kinda meaningless. After a few cycles, your low capacity cells may turn out to be your highest, or visa-versa. I've seen 30% boosts in LiPo cell capacity after about 10 cycles. I don't understand what causes this, but it happens. After you put 10-20 cycles on the packs, you might be suprized to find cell capacity all end up inside of 5% of eachother.

[Ypedal]

hehe.. would you believe this guy only plans to use the pack 3 or 4 times a year !!!!

[Ypedal]

Also, what did you use to determine the mAh of the packs?
Thanks
--Dan

my Thunder Power 1010C charger shows mah going in on a digital display !

[BenMoore]

Does anyone have test data on the 5Ah Turnigy packs yet to confirm their suggested "20-30C" performance
Can anyone do a quantitative voltage sag comparison with the Zippy 15C (or the 20C) packs using the same discharge current

I was about to pay the extra for the 15C Zippys to get a weight bonus (624g for a 24S 10Ah pack) but if the Turnigys have significantly less sag/internal resistance they may well be the best value all round.

Either way, the future is looking bright for affordable, high performance LiPo's!
Thanks for sharing the good news guys

[Hyena]

How'd you go scaling the fences of customs Methods ? Got your lipos yet ?
I do



Quite speedy shipping actually, they hit the HK post office on the 17th, left on 18th, hit Aussie customs on the 22nd and were on my door step on the 23rd.

[johnrobholmes]

At least one pack has a shoddy connection from the last batch I got. My buddy's system keeps cutting out, and we have narrowed it down to the packs. Probably a bad solder joint.

[CNCAddict]

Yeah, I received some flightmax packs from HC with spotty tab solder joints. Really need to go over these packs closely if you want something very reliable in high vibration applications (what isn't?).

[methods]

How'd you go scaling the fences of customs Methods ? Got your lipos yet ?

Actually... I got mine yesterday
8 6S 5Ah packs and a new charger.

In general I always cut off the main plastic connector that they supply. I have seen several that were a disaster waiting to happen.

As far as the internal connections, I have never had a problem and I have no intention of cutting open any packs.
I think more damage can be done taking them apart and reassembling... I have shorted out too many cells fooling around.

This time around I am going to use Anderson connectors.
They are perfect for building up Series parallel blocks.

Not sure if you guys noticed, but Hobby City is now carrying the 12" 6S extensions. These are perfect for building up large, cell level, parallel packs.
I usually reinforce them with glue and build big Y cables.
I also have a thread somewhere where I show how to take board mount JST-XH 6-pin 90 connectors and use them as sacrificial gender changers.

Running these in parallel at the cell level is critical for managing the balancing. Just keeping 24 cells in balance is hard enough without making it 48, 72, or 96...
I am going to resurrect my 24CH BMS board. Last time I played with it I punched 100V through the 12V circuitry and blew the components right off the board.

-methods