Zippy Flightmax / Turnigy lipo testing

[El_Steak]

When are you taking orders!?

Nooooo!

They are a biatch to make. Took me an entire Saturday afternoon just to make 4 of them

The range of opinions I found on fuses in ebike applications is very wide. I raised that issue back in January and got opinions ranging from "Fuses are for wussies" to other members who protect each individual Lipo pack with their own fuse.

The conclusions that I drew from those posts and others here were:

1- The fuse is there to protect the battery against your stupidity when monkeying around with your wiring (happens a lot with RC Lipo packs)
2- The fuse is not a substitute for current limiting. It should be rated high enough so it never blows when you ride your bike hard.
3- The fuse should be rated low enough so it does blow when you act in a stupid fashion as stated in point 1

My controller is rated at 100 amps. In reality, it will peak above 200A for spikes so I guestimated that a fuse rated at 200A would be a fair compromise between point 2 and 3. In retrospect, maybe 125A or 150A would have been sufficient, but the only way to know would be to test it out by shorting my pack and you can bet I won't try it

Its also important to note that the rating of a fuse by itself is not enough information. There are other important factors such as its tolerance and trip time. This document contains good information on the tolerance and trip time characteristics of different types of fuse (MAXI, ANL, AGC, etc.)

 

[Gregory]

El Steak, thanks for the link to the fuse pdf

I have a maxi fuse but with 10 sec trip time at 200% it's not the right tool for the job.
I'm going back to car blade fuses, and might look at the ANL fuses in the future.

 

[liveforphysics]

I've made some of the best Turnigy LiPo destructive testing videos EVER!

You guy's are going to love this stuff, and it's all filmed in HD.


In one vid, I start with a fully charged 5Ah LiPo cell, put it on a charger set to do a big string of NiCd at 10amps charge rate, and just let it run.

The cell takes 3.5Ah additional charge into it before it blows!!! WTF??? And it took the first extra 2Ah into it with no cell heating at all, and this is at a 2C charge rate! It gets to 5.7v before it blows.

Then I use a massive high current charger to bring up a headways 10Ah cell to 19V! And shoot it with a cross-bow, then smash it in a vise.

More vids to make this morning.

Here is a little teaser pic

 

[cell_man]

Great pic Luke :lol:

I especially like the charred Icharger and DMM which really add to the whole dramatic effect


El Steak, really like the inline fuses, excellent idea and so much better than using the bulky carriers they normally come with. I'll defo be using some of those sometime

 

[liveforphysics]

I just got a LiFePO4 headways cell to explode flames, and sustain a collum of flame blasting out of it for like 45seconds!

It was fantastic!

I gotta say though, these things are extremely safe. It took 8C charging up to 21v, followed by a 1500w heatgun right on the side of the cell for like 10minutes... I was almost ready to quit the test, then pop! Woosh! Pillar of flames!

And the whole test is filed from intimate range in full 1080P.

 

[Ypedal]

*squirt

 

[Doctorbass]

I just got a LiFePO4 headways cell to explode flames, and sustain a collum of flame blasting out of it for like 45seconds!

It was fantastic!

I gotta say though, these things are extremely safe. It took 8C charging up to 21v, followed by a 1500w heatgun right on the side of the cell for like 10minutes... I was almost ready to quit the test, then pop! Woosh! Pillar of flames!

And the whole test is filed from intimate range in full 1080P.

Where are these fanmous video Luke!!

What would be nice is to test if that extra 2Ah you ve put into the turnigy, is usable capacity on discharge!.. ex 7Ah instead of 5.. just to know.. not to use!

Or... if that extra 2Ah is like slowly building heat inside the cell and modifying the chemistry stability... and not translate to 2Ah extra on discharge...

Doc

 

[Doctorbass]

About the fuse, i can say that these little 32V car fuse just explode if they blow under 100V system!

They completly vaporise and there is no more plastic or metal!.. just like we usually call it: Plasma Event!

at 12V, there is just a little pop or tic sound...

I would not use a 12V circuit breaker for setup above 32V. ther can weld !! on Make or Break contact.

Doc

 

[Hyena]

Awesome Luke!
I've been waiting for these videos, sounds like the wait will be worth it

Also in other lipo related sillyness
http://www.endless-sphere.com/forums/viewtopic.php?f=6&t=17335

 

[liveforphysics]

Whoa!!!

I was over-charging a 2P pack of 4Ah cells, and I had the camera a tad bit close, the first cell goes off, and just happens to very directionally explode flames right into the camera... So, I know the second cell burst won't be far behind, so I'm frantically trying to move the $$$$ camera backwards when the next cell goes off. The video is outstanding, and it blew fire in my face, which was smelly (hair), but also awesome. No injury, just a little burnt eyelashes/eyebrows, and most important, the soot and debris all wiped off the camera with no damage.

I've got some very strange videos as well. Like a LiPo cell that I charge to 4.5V, then shoot with a cross-bow, it just smokes a bit, then I stab it like 100 times with a razor knife, it just smokes a little, stays about luke-warm, then it smash it with a sledge hammer over and over on a steel table, and it just smokes a little more, and never does anything exciting. I was really expecting the cross-bow bolt to have set it off. Watching the stabbing with the razor knife, it seemed to spark a bit on each stab, and it would spark a bit if I twisted the blade inside it, but it always seemed to vaporize away the areas contacting and shorting almost instantly, so it never heated up or flamed or did anything exciting.

Also, nothing I tried could actually get an explosion, only blasts of flame, but never a pop from LiPo, only the headways cell had a bang to it. Also, with the LiPo, even with extremely abusive charging, there was always at least 15-30seconds of white smoke streaming out before it vented flames. I know we've all seen the video where the guy pokes it with the nail and it just explodes into flames instantly, I think that might only be true for old-school gen-1 LiPo. These 5Ah Turnigy packs are very very tolerant of physical abuse like smashing and stabbing and puncturing and crushing etc. I wasn't able to deal any physical abuse to them to make them do more than smoke.
It required extended over-charging to get them to explode into flames, and I'm talking VERY over charged.

 

[Hyena]

Outstanding!
Coming soon: Mythbusters, the lipo edition!

Chuck one off the top of a tall building too if you get a chance

Sounds like a close call with the flames! Pity you didnt have a second camera set up to capture that! Glad you're OK though. Does this quality as the first case of KF head ? Did you get a picture of your flame grilled melon ? I hope so!
Also glad to hear the camera didn't suffer any damage but damn man, move it back and zoom in!

 

[Doctorbass]

Luke, When will you decide to put one vented cell into water!!!

Where are these 1080p video!!?

Doc

 

[liveforphysics]

Luke, When will you decide to put one vented cell into water!!!

Where are these 1080p video!!?

Doc

I will cut open a cell and put it in water. That's a good video that I forgot to do, but I will get it done tomorrow.

Here is a thread I made in the battery section with some of the videos.

http://endless-sphere.com/forums/viewtopic.php?f=14&t=17354

 

[liveforphysics]

Luke, When will you decide to put one vented cell into water!!!

Where are these 1080p video!!?

Doc

Re-check the thread Doc. I made a LiPo in water, then saltwater, then Nitric Acid thread just for you.

 

[methods]

I populated boards today for V2.0 of my BMS

Link:
Click here for BMS Porn

View attachment _020_Charger.jpg


V3.0 will be for you guys -> modules of 12S.
My pricing will be very competitive.... because I will be selling it only to further the electric revolution, not to make a profit 8)
I can make some dough off of "advanced features" but he base model will be dirt cheap.

-methods

P.S. Before anybody asks -> yea, I tested it at full blast 1.2A/ch 125W with 3 fans running. The case never gets more than 10C above ambient. It is all about proper cooling.

 

[Scorefield]

Click here for BMS Porn

I'm speechless while I'm scratching my head, sorry for my language..ffs well done.

 

[jsoar]

A question:

I have made a couple of short flights in my ultralight airplane powered by a PERM PMG-132 motor, with a Kelly controller set to 200 amps max, and a battery pack made up of 21 Zippy Flightmax 5000 mAh 6S1P 30C units, 3 in series, then 7 of the strings in parallel, connected by a simple wire harness. It becomes an 18S pack with the full resting charge of the pack ending up around 75.5 volts.

So far I have been balance charging each Flightmax individually with a couple of Turnigy Accucel-8 RC chargers, by disconnecting each power lead and reconnecting to the chargers, which is very tedious, time consuming needing constant watching and moving to the next unit, and somewhat risky if I mess up the connections.

I read thru all the posts in this thread and saw mention of using multiple power supply units connected in series to get a higher voltage for charging. I was wondering if it would be feasible to connect 3 Turnigy's in series so I could at least balance charge a 3S string without as much fooling around with the connections.

Maybe with the 6S balance taps of each Flightmax connected to each charger, it could still balance each unit, if all the balancing is just done by discharging high cells to 4.2 volts, which is what the Turnigy charger appears to be doing.

Any comments on this?

Thanks,
jsoar

 

[drewjet]

hjsoar, very cool to hear of your plane. I cannot speak of the ability to do what you want with the Turnigy chargers, but I do exactly what you are asking with FMA BalancePro chargers on my E-Motorcycle. As long as all the power supplies are issolated, I think It will work.

I actually asked FMA before doing it and they said no I can't. But I am hard headed and thought as long as tey were isolated it would. My gamble worked out for me. Worst case senario should be a single blown Charger.

Got any pics of the plane?????

 

[El_Steak]

A question:

So far I have been balance charging each Flightmax individually with a couple of Turnigy Accucel-8 RC chargers, by disconnecting each power lead and reconnecting to the chargers, which is very tedious, time consuming needing constant watching and moving to the next unit, and somewhat risky if I mess up the connections....I was wondering if it would be feasible to connect 3 Turnigy's in series so I could at least balance charge a 3S string without as much fooling around with the connections.

A plane? cool...

I don't know if the Turnigy chargers are isolated and if you can charge with them in series, but if you already have 3 turnigy accucel-8 RC chargers, you can safely charge your entire pack without connecting/disconnecting anything.

Just hook each 7 pack parallel string to its own charger. To do so, you must parallel all the main power leads to a single connector AND then all the JST-XH connectors to a single balance connector for each string of 7 packs. This has the added benefit of paralleling your packs at the cell level, which is a good thing. You can build the JST-XH parallel harnesses using these.

You can also add a separate charging connector to each of your parallel string so that you can leave your entire pack connected in series while charging each string with its own charger.

Each string will be charged and balanced by its own charger so you have to make sure that the max-charge settings are the same on each charger.

 

[liveforphysics]

A question:

I have made a couple of short flights in my ultralight airplane powered by a PERM PMG-132 motor, with a Kelly controller set to 200 amps max, and a battery pack made up of 21 Zippy Flightmax 5000 mAh 6S1P 30C units, 3 in series, then 7 of the strings in parallel, connected by a simple wire harness. It becomes an 18S pack with the full resting charge of the pack ending up around 75.5 volts.

So far I have been balance charging each Flightmax individually with a couple of Turnigy Accucel-8 RC chargers, by disconnecting each power lead and reconnecting to the chargers, which is very tedious, time consuming needing constant watching and moving to the next unit, and somewhat risky if I mess up the connections.

I read thru all the posts in this thread and saw mention of using multiple power supply units connected in series to get a higher voltage for charging. I was wondering if it would be feasible to connect 3 Turnigy's in series so I could at least balance charge a 3S string without as much fooling around with the connections.

Maybe with the 6S balance taps of each Flightmax connected to each charger, it could still balance each unit, if all the balancing is just done by discharging high cells to 4.2 volts, which is what the Turnigy charger appears to be doing.

Any comments on this?

Thanks,
jsoar

You don't even need an RC charger. I charge 4s strings of 6S packs (24s all together) only using power supplies. It's simple to set the CC/CV profile as you desire. 1 connector to charge, and charging is as fast as you can draw power from the wall outlet. To balance, you still need to connect to the taps with a balancer (or RC charger), but you shouldn't need to do this more than every 10-20 cycles or so if you're not deep-discharging the cells.

I want to see pics of your ultralight as well! I've been dreaming of doing something like you described for a few years. It seems like it would be so fantastic.

 

[Hyena]

Cool, I too have though about a lipo powered ultralight but I have too much to live for :lol:
I hope you have a very conservative low voltage warning otherwise you'll give new meaning to lipos 'falling off a cliff'!

As El steak said I'd be inclined to keep all your parallel packs wired together to essentially create a 3 lots of 6S 35ah packs. It'll make charging easier and it'll help keep the packs in balance better too. I'd get 3 S350 meanwells set to 25v and charge each 6S 35ah pack - or you could just use one but it'll take ages.

+1 for pics

edit: I just noticed these turnigy chargers hobbyking are selling now.
They're clearly just 4 of the little 50w 6S B6 type chargers thrown together in a purpose built case but still, it might appeal to n00bs or those scared of using meanwells or what ever and for $100 they're pretty cheap (same price as 4 of the cheap $25 chargers but neater if you're that way inclined)

http://www.hobbyking.com/hobbyking/store/uh_viewItem.asp?idProduct=11170&aff=81978

 

[jsoar]

Thanks for the replies.

Since I already have the chargers and don't want to take a chance of smoking them, and I need a full charge every time for take-off, and there will be a rather deep discharge every flight, I'm leaning towards El_Steak's suggestion of paralleling them and plugging in the combined balance taps to my 3 chargers.

I am diagramming it out and it looks like it might be easy to convert what I have to that way of doing it. I'll try to post what I came up with for comments, I don't want any KFF.

I keep the plane at an airport and do the charging at home, no chance of having the pack connected to both the plane and the chargers at the same time. I charge the pack the day before a planned flight, so a slow charge rate is ok.

A concern might be that if one cell goes flat in one Flightmax unit, because they are in parallel, it could take out 6 other units with it. But at least they are a lot cheaper now to replace, and easy to just plug-in.

I uploaded a picture of the battery box as it is now. You could visit my Yahoo group to see and read all about the plane there. http://groups.yahoo.com/group/RedTailHawkUltralightSailplane/

There are several others doing similar development, like http://www.electraflyer.com/
and http://www.lightsportaircraft.ca/volume3-issue39/webcast-2/

jsoar

 

[liveforphysics]

Big respect to you Jsoar!

That's a serious pack you've got there. Much love for your outstanding E-ultralight.

Best Wishes,
-Luke

 

[mwkeefer]

Hello all,

It's been a while since I've posted here but that's because I've not had any discoveries worth sharing... until now.

I have many 15S2P packs which I have mostly thrown together from 6x5s or 2x3s+4x6S packs I had about when I began testing things on a rolling platform (ebike)... these packs have puffed a bit and had some other issues (out of balance) over time so since these were all wired up with parallel balance expansion boards (thanks gary) and homemade 3.5mm connectors for paralleling the packs with a final series harness of the same plugs... I decided to solder up a block and see how the performance would be effected!

The results are nothing short of a miracle... before this I couldn't get this pack to charge even to 4.15v at a single shot because I would hit 4.19v on a high cell and have to interrupt the charge cycle for a balance down before finishing the charge process... (first indicator there was a problem), even after I had taken the pack in question down to 5S2P chunks and charge / balanced with an iCharger to 4.16v per cell they went back out of balance within a single cycle.

Now that I have the packs soldered (discharge and balance lines, all leads coming from packs kept short as possible and 18G used for terminating the 10AH 5S balance taps) the pack nearly autobalances now... and I mean that without balancers connected but bulk charging with monitors connected... +- 4mv is the average if I wait to C/20 or .35A - my meanwell is currently pushing 7.2A average durring CC and peaking around 440-450watts constant output... I did a fan mod and removed a shunt but it's not lowering the current, this meanwell has been running this way for about a month or perhaps 40-60 cycles from nominal to 4.16v per cell with no ill effects so far.

Hope it helps!

-Mike

 

[AussieJester]

I decided to solder up a block and see how the performance would be effected!
The results are nothing short of a miracle...

This is how Hyena has his packs and has often said they stay perfectly balanced also.

KiM