Zippy Flightmax / Turnigy lipo testing

[methods]

If these promos keep coming I'm going to need a lot more of those 'Methods' 10 KW controllers. And my first one is still in USPS tracking limbo... Entered a truck in California 9 days ago and has never been heard from since.

I ship all my regular packages 2-3 USPS Priority Mail
Unfortunately your ordered a hub motor which bounced you out of the Priority bin to Parcel Post.
You are also on the East Coast... Parcel post is quoted as 7-9 *mailing* days "average" which means that you are about on schedule.
Priority could have been used but you would have had to pay over $70 for shipping

-methods

[SpeedEBikes]

I'm in Chicago, not the east coast. Perhaps I better check the address again on the tracking notice...

[methods]

Considering that I am on the water in San Francisco.... You are on the East Coast from my perspective

Lets take this off line - We can check the ship date and calculate the transit days.

-methods

Edit: I just did the math - today is only the 9th shipping day so it is not late yet.

[GGoodrum]

I agree about 12-gauge being fine for multi-"p" applications. My real reason maybe going with the Turnigy's is I figured they also used smaller bullet connectors, which would mean they wouldn't fit into my LVC/parallel adapter boards, shown below, but after checkig again, I see they do still use the 4mm bullets, so all's good.

6s4p LVC-Parallel Adapter-02.jpg

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[methods]

You know... I bought those 90 degree board mount Anderson connectors we were talking about......

I have also been thinking about going to a more modular system. Groups of 6S in either 1P, 2P, or 3P.
I wonder if I can hack one of those boards to work wit the Anderson board mount connectors?

I am still not sure about the modular yet since the beauty of Anderson is their ability to chain directly in series without a middle-man connector.
Looking at Matts trike and all those wires he had to solder up gave me shivers remembering the bad-old-days of Deans connectors.
I still have about a million Deans. I should probably sell them.

-methods

[voicecoils]

To match my six Flightmax 15C 5S1P packs and the one BM-6 unit I already have I grabbed the following:

Code: Select all

1x #HKB-Medic/10328 Hobby King Battery Medic System 6S variations = $23.95
2x #BM-6/8927 BM-6 Cell Voltage Monitor 2-6S Lipo (New Version) variations = $25.90
2x #JSTMF-5S-20/9738 JST-XH 5S Wire Extension 20cm (10pcs/bag) variations = $8.44

The plan is to parallel the balance taps for the 3S2P setup together and use a BM-6 on each for voltage monitoring and lvc per cell pair warning buzzing. The 6S battery medic can then be used on each pack to discharge each cell to the same voltage then charge up all together, balanced.

Comments?

[methods]

Step in the right direction
Paralleling at the cell level is right on the mark
Using cell level monitoring is right on the mark
Balancing *before* you charge is wise - though it may not work like that for a few reasons.

Many balancers wont turn on until the cells are at a certain level - say 3.8V
Balance currents will be very low so expect it to take some time
The lower the cell voltages the slower the balance because the less the potential is across the shunt resistor

btw - just FYI to anyone else - never balance a pack that is near empty
When a pack is near empty that means that one cell has hit LVC while other cells are still holding some capacity
Every pack has slightly different capacity in each cell
If you balance them when they are empty they will be out of balance when they fill up.
Make sense?

Anyway - I like your plan - though what I would do is set the charger for a volt or two under HVC and just charge/balance at the same time
If you want to, once the pack is balanced, you can pump the last volt or two in.

-methods

[voicecoils]

Step in the right direction
Paralleling at the cell level is right on the mark
Using cell level monitoring is right on the mark
Balancing *before* you charge is wise - though it may not work like that for a few reasons.

Many balancers wont turn on until the cells are at a certain level - say 3.8V
Balance currents will be very low so expect it to take some time
The lower the cell voltages the slower the balance because the less the potential is across the shunt resistor

btw - just FYI to anyone else - never balance a pack that is near empty
When a pack is near empty that means that one cell has hit LVC while other cells are still holding some capacity
Every pack has slightly different capacity in each cell
If you balance them when they are empty they will be out of balance when they fill up.
Make sense?

Anyway - I like your plan - though what I would do is set the charger for a volt or two under HVC and just charge/balance at the same time
If you want to, once the pack is balanced, you can pump the last volt or two in.

-methods

Thanks for the feedback Methods. Here's what I'm thinking: So far my lowest cells are 3.831V so I can throw the Battery Medic on each pack and draw each cell down to say 3.82v, then I'll connect the whole 3S2P pack to my 10A charger set to 61.5v (4.1v/cell). It will charge up perfectly and then stay in balance forever. Right?

I don't see how I can charge and balance the whole 3S2P pack at the same time with just one 6S discharger...

[methods]

One pitfall to look out for is that a 6S charger will put each set of 6S cells in balance with each other, but not with the other packs:

Example:

Pack 1 Balances to lowest cell of 3.9V
Pack 2 Balances to lowest cell of 3.8V
Pack 3 Balance to lowest cell of 4.0V

Now what?

Your only choice is to manually discharge the higher packs or to tie all the packs together in parallel.
You already know better than to tie all the packs together in parallel because it is too mistake prone (read back 10 pages) so your only choice will be to be patient.

You will find that charging to 4.1V per cell will allow you to get away with balancing only once every 10 rides or so. Just keep an audible monitor on the cells when charging.

Oh wait - cant you set a specific voltage on the battery medic for it to balance down to?
Yea - I remember Gary saying that.
SO - in that case you could get all three packs equal.

-methods

[GGoodrum]

The Battery Medic not only lets you set the minimum voltage the balancing is enabled, but it can also be used in a balanced discharge mode, which lets you balance to a specific voltage, which can be set anywhere from 2.0v to 4.2V, in .1V increments. It also has about 300-400mA of balance current, which is not bad for a unit this size, with no fan. I'm actually working on a adding a shunt booster to these that will bump the shunt current to up over 1A. Here's a shot of two of these working with one 12s section of the pack I have on my Townie:

12s LiPo Balancer with HVC Cutoff-05.jpg

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Anyway, so far I can't find anything to not like about these units.

-- Gary

[MrKang]

The Battery Medic not only lets you set the minimum voltage the balancing is enabled, but it can also be used in a balanced discharge mode, which lets you balance to a specific voltage, which can be set anywhere from 2.0v to 4.2V, in .1V increments. It also has about 300-400mA of balance current, which is not bad for a unit this size, with no fan. I'm actually working on a adding a shunt booster to these that will bump the shunt current to up over 1A. Here's a shot of two of these working with one 12s section of the pack I have on my Townie:


-- Gary

Is this picture taken in charging mode ? or do the balancers draw 4.91A for discharging and balancing ?

[GGoodrum]

s this picture taken in charging mode ? or do the balancers draw 4.91A for discharging and balancing ?

This was during a charge, and I happened to use a 5A/48V Vicor supply I had handy. The board that the two BMs and the WatsUp are attached to has the HVC logic and the active cutoff circuit, and then a matching 18-pin plug that connects to the pack. Anyway, after about 2 hours, the current was down to about 200mA and all the cells were right at 4.15V

I tried two Meanwell S-350-24 24V/15A supplies in series, but without a true CC mode to limit the current, it jumped up over 20A in a heartbeat, and was making some weird humming, so I shut it down. Tomorrow I'm going to try using the throttling logic from the main BMS control section, which should act to limit the current and the voltage.

-- Gary

[Hyena]

As long as the packs aren't too far out of whack wouldn't you be better to balance on a full charge ?
I know with my turnigys with > 100 cycles on them they get pretty badly out of shape if you pull close to 100% from them - delta v is ofter around 0.5v with some cells hitting close to 3.0v while others are still 3.5ish. Connect em all in parallel and charge them up with a power supply and shortly after they're all pretty good with a max delta v of 0.04v
Especially considering you can set the balancing voltage on these battery medics I'd charge they up to a voltage that works out at 4.15v/cell, then balance at 4.1v then give them another top up charge and see how they look. After cooking a little hyperion balancer I'm not going to balance while charging any more, atleast not for now.

[Hyena]

Also,
lookie what I just found HK/HC are now stocking. Niccce

http://www.hobbyking.com/hobbycity/stor ... &aff=81978



It's showing as $2.86/metre for me. Bargain
They show red and black but only have red listed at this stage. Meh, red makes your bike faster anyway
edit: They DO have the 100mm stuff in BLACK listed now. Wow, talk about spotting live updates as they happen

Also 50mm in RED and BLACK
and they also now have stock of smaller 14mm heat shrink which is good for multiple 10ga wires
http://www.hobbyking.com/hobbycity/stor ... &aff=81978

[GGoodrum]

As long as the packs aren't too far out of whack wouldn't you be better to balance on a full charge ?
I know with my turnigys with > 100 cycles on them they get pretty badly out of shape if you pull close to 100% from them - delta v is ofter around 0.5v with some cells hitting close to 3.0v while others are still 3.5ish. Connect em all in parallel and charge them up with a power supply and shortly after they're all pretty good with a max delta v of 0.04v
Especially considering you can set the balancing voltage on these battery medics I'd charge they up to a voltage that works out at 4.15v/cell, then balance at 4.1v then give them another top up charge and see how they look. After cooking a little hyperion balancer I'm not going to balance while charging any more, atleast not for now.

When I started, I had one 6s3p group that had most cells at around 3.91-3.93V, and another 6s3p group with the cells at around 4.01V-4.04V. The first thing I did was set the BMs up to do a balance discharge to 3.90V. I then hooked up the supply, which was set to 49.8V, or 4.15V per cell, and I just had the BMs set to regular balance mode. When the current dropped down to under 200mA, all the cells, in both 6s3p groups were right at 4.15V.

[AussieJester]

I am puting through an order later today, i wanted some 4mm bullet connectors but one half is on back order so have opted for the 3.5mm for now along with some 10AWG wire these should suffice no? Gary has the connectors on the LVC boards already so the additional connectors im ordering will be for additional wiring in the battery enclosuer...SO ..8 Turnigy packs ran into 480 ish dollars plus 80 bucks freight ... invoice Have funds being deposited in my bank account will put through order later this afternoon and initiate payment via PayPal ...one step closer to full GanGSTA status LoL... Hopefully this wont entail KFF as well :-p

KiM

[vanilla ice]

AJ.. which half is on backorder? Order these and you get both together, plenty in stock. http://www.hobbycity.com/hobbycity/stor ... oduct=9283 I just got mine today and its all there.

[AussieJester]

AJ.. which half is on backorder? Order these and you get both together, plenty in stock. http://www.hobbycity.com/hobbycity/stor ... oduct=9283 I just got mine today and its all there.

The non-reddy bit i bought the above though so all good cheers for that totally missed them...i put them through on a separate order as i have now put the initial order through ...extra 3 bucks post pft...

KiM

[mwkeefer]

Hey guys!

My iCharger decided to have a fireworks display on my home workbench tonight (about 10 minutes ago) - wish I had video, it was kinda neat (now that the house didn't burn down and the lipos didn't blow up).

I was doing a relatively mild charge/discharge cycle on a 10S pack @ 5AH from 4.15v to 4 for 3 cycles, had just started it with cells at resting voltage of 3.94v-4.00v per cell across the pack... 1.5 minutes into the charge cycle I heard a noise, saw a flash of light within the iCharger and finally as I jumped up to pull the plug flames from the fan area. I got to the cord in time then yanked the pack as fast as I could - pack is fine, charger is at best a parts source (only a few mo old but I didn't keep box to return to HK) - I haven't opened it yet but whatever went, kept going until I pulled the mains.

The only difference from my normal "routine" was the use of a 24v meanwell turned down to 17.4v (it stayed stable, I just checked the logs) as opposed to my normal old 14v supply I was using. I have done about 10 successful charge cycles with the iCharger1010B+ and the meanwell so I think the darn thing just gave up the ghost (I must have put over 1000 cycles on it all together).

So - what should I get for a precision hobby style charger now? Suggestions are welcome.

-MIke

PS: No fire and no lipo damage, ps is fine too but... my god does it stink to high heaven in here... Guess until I can get some hobby chargers / balancers or some of gary's balancer boards (or a new iCharger) I'm doing it the meanwell / cellmon8 way (outside).

[Hyena]

Kim you can probably change your order if you haven't payed yet. As Vanilla Ice said get the ones he linked, even if you just want the bullets themselves you can throw the rest away and still be better off. The packs all use 4mm connectors so for the sake of compatibility you probably dont want to go down to 3.5mm ones, especially when you're going to order more later.

Mike, I had a B6 charger go up in similar fashion for no apparent reason. You can see in this pic which part let go. It took a week for the smell to get out of my workshop! I came back an hour or so later too and I could smell it as I approached the door. I feared the worst, half expecting to see a crater under my bench half way to china Good to hear the lipos weren't damaged

[methods]

Great time to remind everybody that Lipo chargers are nothing more than power supplies.
Dont let them give you a false sense of security.

My charging setups may be down right hazardous but I respect them so they keep me on my toes.

-methods

[SpeedEBikes]

The iChargers aren't just power supplies. They are far more sophisticated and therefore possibly more prone to bizarre and sudden failure. Has anybody else had these go up in flames for no apparent reason?

I love the damn things but realize that when critical functions such as regulating output voltage are under active software control it opens up the possibility for software bugs to result in catastrophe. I'm not saying that's what happened here, but I could easily imagine a scenario that involved no hardware failure at all or perhaps a minor hardware failure that resulted in inaccurate readings for voltage or current leading to meltdown.

I'd encourage everyone who encounters trouble with these chargers to report it in as much detail as possible. The company seems fairly responsive to posts made on the HobbyKing board and if there is a pattern of failure it will emerge more quickly if we do a good job reporting the failures

[methods]

The iChargers aren't just power supplies.

My point was that they are not some sort of magical device that when used properly will protect you from lipo failure.
I have owned and blown up just about every version of the icharger and its variants btw.

I would argue that they are just power supplies in how they charge - nothing sophisticated going on - nothing like what happens with lead or Ni.
Simply CC/CV
That's why I advocate saving your money and charging with a simple power supply and manual balancer.

I am however not ready to point the finger at modern technology and say that we should go back to vacuum tubes.
Power supplies pop and that is that - any number of passive or active components in a regular power supply can fail causing meltdown.
How many opamps and comparators and PWM sources do you suppose are in a modern supply?

Being a firmware expert I have no firmware phobia - once programmed - they are just another active component as far as I am concerned.
No different than any integrated circuit on the board.

Software bugs are another issue.
I will bet my balls this was not a software issue.
I have personally seen crap solder joints on these units. Pop yours open and look.
I put my money on a heated up cold joint.

-methods

[mwkeefer]

Methods - forget LiPo failure - this could have been far worse...

After dissection (not much) it's clear the LOW side FETs of the switching power supply burned clean through the PCB (yep all 3 of the low side - closest to the power input) and took out the cap and a good bit of crap above. That said...

Educated guess on cause - LOW side fets tried to turn on while HIGH side was fully on already... odd, gates should have been logic level controlled for hardware based "short" (or crossover if you prefer controller terminology) protection but I guess they weren't just like there was no internal fuse or diode to BLOW before the gates cooked the PCB like a plasma cutter (no crap, the insides are blackened bad - top and bottom and two of the three fets burnt so badly they came right off as I pulled the PCB - crispy cajun style one with a big messy hole in it the rest just extra cooked - toast you wouldn't eat.

It's kinda sad when you think about it... If the exact same thing (input side issue with gates/fet/etc) causes a short on a Meanwell it blows the fuse if hiccup mode doesn't cover the damage - on better supplies the likes which Methods uses - probably no pop fuse, no blown fet, resettable breaker? LOL

Seriously the only issue is balance - right now I can get about 30mv difference bulking 3 x 5S as a 5S3P pack (balance taps paralleled before charging).. this pack was getting to 20mv but then the iCharger incident, it should correct back to 20mv within a cycle or two.

Methods... what resistor do you use to short your cells out for balancing (kidding but I've thought of a simple 4v dissipator, single cell to draw down the higher cellls in a manual process durring charge until the slower cells catch up).

-Mike

[MrKang]

Funny, i had the same experiences with my IMAX B6 which is probably the same manufacter of the ICharger. All China Stuff.
I bought 2 of those units cause they were very cheap and did there job done for the money. But after 2 cycles i connect my normal 13.8V power supply and then i heard a sparkle/sissing sound together with the smell of burned resistors. A small smoke fume came out of the box....
After that i opened the box to see what was broken...I still didn't figure out what the hell was happened. I suspect a FET on the output of the charger which has type : IRF 540N but while measuring it i didn't detect a shortcut. Then i measured the two large diodes on the input. One of them had a measuring of 0.179mV , i don't know if this is normal. I thought all diodes are arround 0.450mV




I'm gonna measure some more components and find out who's to blame.