Zippy/ Flightmax / Turnigy/ Blue lipo testing (pt 2)

[neptronix]

What you mean by 'cliff' is that you've discharged the pack down almost to the point where they're 100% drained, right?

That looks like it beats the hell out of them..

Do they get wacky out of balance if you use about 70% of the pack's total?

 

[GCinDC]

What you mean by 'cliff' is that you've discharged the pack down almost to the point where they're 100% drained, right?

That looks like it beats the hell out of them..

Do they get wacky out of balance if you use about 70% of the pack's total?

if you look at the lipo discharge curve, the voltage plummets at the end of the pack's capacity, whatever that is. i only use up that much once every other month. i may have a couple low cells. i'll have to keep an eye on those two that went out 0.6V from the rest. if at rest they were 3V, they musta been much lower at 40A, but i wasn't riding like that for long. just recording...

as far as beating them, they're 25C, and i'm only using them at 5C... i usually charge them before they're half empty.

 

[neptronix]

Yeah, i've seen that. I guess what i'm asking is it they get out of balance like this if you discharge them to the point where you've got more battery capacity left. ( you had 0.6Ah left in the pack, right? )

 

[GCinDC]

Yeah, i've seen that. I guess what i'm asking is it they get out of balance like this if you discharge them to the point where you've got more battery capacity left. ( you had 0.6Ah left in the pack, right? )

they get out of balance when deeply discharged. i consider the pack done at the top of the cliff, whereever you want to measure that. so nominally my packs are 10Ah, but they may now only be 9.4Ah packs... Not sure exactly how they measure. Hope I'm answering your q.

 

[neptronix]

Ah so.
Perhaps i will assemble a pack that is slightly oversized in order to avoid this.

 

[geoff57]

Hi
GCinDC do you use a LVC of some kind when you are riding I see you have have a BM6 have you got them fitted on all your packs while you are riding or maybe do you have the system by Gary fitted to protect from a cell going low like this.
It might help save your cells from further damage if you do fit them even if from the sounds of things you will only come close to tripping the circuit once every few months.

Geoff

 

[GCinDC]

Hi
GCinDC do you use a LVC of some kind when you are riding

afraid someone was going to ask me that. two wires on my little db25 are messed so those bm6s beep all the time. been meaning to fix it.

meanwhile, usually, i unplug the parallel harness from charging 5s, all cells reading 4.15/6, the plug in 4Ah down the road, all 5 cells reading 3.75-8V. perhaps parallel charging has me fooled though!

what's the status of gary's lvc thing?

 

[geoff57]

two wires on my little db25 are messed so those bm6s beep all the time. been meaning to fix it.

meanwhile, usually, i unplug the parallel harness from charging 5s, all cells reading 4.15/6, the plug in 4Ah down the road, all 5 cells reading 3.75-8V. perhaps parallel charging has me fooled though!

what's the status of gary's lvc thing?

Hi
I'm not trying to sell anything here just think that I would say something, Gary has done a great LVC circuit design with a built in 4 way balancer board it comes in 6 channel and 8 channel flavours I have some of the first ones he did which are virtually the same as the latest versions, the latest versions have added zeners to protect the boards from going wrong as a result of over voltage into the sensor component the TC54, he does do it for two types of battery as well all you have to do is change the TC54 in each channel. His latest versions like the LVC/HVC that he made before this latest offering has the ability to be balanced using his new balance boards that will be coming out very soon.
The only problem is that all he sells is the bare boards, kits or boards and part kit, this ,means that ,you have, to assemble them yourself, I have a lot of lipos and did not like the idea of this so I started a project to convert Gary's very good design into a SMD version with no self assembly the thread for this is the micro LVC http://endless-sphere.com/forums/viewtopic.php?f=14&t=18834 I starts ,with a direct copy but quickly dropped the parallel balance board in favour of building my own out of strip board available from any electronics company, I concentrated on the LVC circuit in my mind the important bit. I will shortly be getting the prototype run to check everything works ok after that I will be going for a mass production run of 3,000 blank boards they will be populated so they are suitable for LiPo and LiFePO4 in both 6 and 8 channel versions, now unlike the BM6 that has to be fitted at the end of balance setup both Gary's boards and mine can be fitted between the batteries and the charger, as gary's is self assembly you have a choice of ,what connector to solder on to the board with mine it comes as a compleat unit with an input from the battery and an output to a R/C type charger there mis no point in fitting pads for heavy duty balancing is no good as the charge would have to go out the input connector (not a good idea) if you have made balance boards for the system fit the wires on there I was going for small and I did that at about 30mm by 43mm, at $15 for the 6 channel and $20 for the 8 channel with reductions for bulk orders I think they are a fair price, silicone covered balance extension wires will be available as well in 5,6 and 8 channel to start with.
For you I think that either my one or Gary's would work put between the battery packs balance wires and the db25 you then connect all the LVC trip wires together and feed one of the end ones out to the controller and connect it to either the brake wires or the throttle wires depending on your motor controller and how you have it set up.

Geoff

 

[GCinDC]

Good news, rode in today, long commute 8Ah ride, and before charging up, checked each of the 20 cells, and only 0.02-35V delta per bm6/pack.

...so I started a project to convert Gary's very good design into a SMD version with no self assembly the thread for this is the micro LVC http://endless-sphere.com/forums/viewtopic.php?f=14&t=18834

Awesome. I read "fantasyland.com" and thought that post was a joke. I can only read so much balancing stuff before my eyes glaze. I do know there are a ton of noobs out there drooling for lipo but afraid to start cause of the dangers and challenges of building these packs. And these balancing things are a PIA. So, yeah, I'm interested. But when will they be ready!? And can they be coupled with a charging solution? I'd love to bulk charge, but bought the wrong (hiccuping) meanwell, and haven't had time to research it further...

Show me all the parts for a Turnigy 10Ah 20s or 24s lipo kit with balance charger, LVC & HVC protection... I'll buy them!

PS. I'm way out of the loop on this stuff, so pardon the ignorance...

 

[geoff57]

Hi
You could say that in a way that thread did start as a joke. Knuckles had found out about my idea to convert Gary's LVC/HVC boards to SMD and started that post before I had done any research.
When Gary started altering the HVC value I dropped the LVC part of the circuit, knuckles did give me food for thought as far as doing a LVC board with no parallel balance part. I talked with some others and they agreed so the project aims were decided opon over the past 2 months I have been through several board designs I am getting them made in china to keep costs down but I had to make sure that they could get all the parts I wanted, I also wanted to make sure that there would be a good distribution network there would be no point in having them made if I could not sell them, I also wanted the price to be low better to sell a lot with a small profit on each than a few with a large profit on each, the last problem to overcome I found ,out was the optos were not that cheap and tying up a lot of cash on a project like this was not something I wanted to do that problem has now been solved by having the boards populate without the optos and then adding the optos only when orders are received. With luck the prototypes will be ready for testing soon as soon as they pass the test's I will go for the mass production run.
With luck it will not be long now keep an eye on the thread.

Geoff

 

[neptronix]

Awesome. I read "fantasyland.com" and thought that post was a joke. I can only read so much balancing stuff before my eyes glaze. I do know there are a ton of noobs out there drooling for lipo but afraid to start cause of the dangers and challenges of building these packs.

^--- ditto. I'm waiting for something like this to come out. I have no experience with LiPO either. A plug-it-in-and-forget-it type system for LiPO batteries would be fantastic. Not that i don't want to know what's going on and have control over them... but i don't want to have to be constantly worrying about them turning me into a 2 wheeled suicide bomber.. lol

I'll keep my eyes peeled..

 

[adrian_sm]

Just monitored my pack during a charge and thought others might be interested.

Setup was two 6s5000mah 20C Turnigy packs, parralleled at the discharge leads.
They were at ~50% DOD. I had the balance leads of one pack connected to the charger, the other pack to the cellog8 for monitoring.
The charger was set to LiIo for a 4.1V charge in balance mode.

 

[icecube57]

Ive taken my packs to the cliff and they appear to be out of balance. at 5.2AH on the 6s 5000mah Turnigy. None of the cells were below 3.4v but i had a .25v deviation on my cells. When I put them on the charger they appeared to stay out of balance until about 3.5 3.6v then they all come up together in voltages with a .02v deviation. and put a full charge on them they were balanced on the top end. So just obey the golden rule and try to stop discharging around 3.3v. Even though they look like they are out of balance... they are not because they are capacity balanced. They are rated to give you a minimum of the rated capacity but whatever you decide to claim past that is your own risk =P

 

[nicobie]

.

Show me all the parts for a Turnigy 10Ah 20s or 24s lipo kit with balance charger, LVC & HVC protection... I'll buy them!

.

Me too!

 

[geoff57]

.

Show me all the parts for a Turnigy 10Ah 20s or 24s lipo kit with balance charger, LVC & HVC protection... I'll buy them!

.

Me too!

hi
Keep an eye on Gary's different approach to battery management the cellog8 charging system / full BMS is getting close to going on sale for those with 20S setups eg 4 5 cell turnigys in series there is always the Icharger 1010b or 3010b both will charge 10 cells at one time they are both a bit expensive though especially the 3010b and to get the most from that you will need a big lead acid battery setup at 24 v to get the most out of the charger, if you have a 24S setup and am not bothers by speed of charging then you could try out the turnigy 4x6s charger or the quatrro 4x6 charger, these last two will be slow but should do the job I am testing out the turnigy with a 20S pack 10AH at the moment time will not be an issue as long as it is not more than about 5 hours from close to flat that should give 8 hours with a 15AH pack should I choose to try it as a lot of my battery packs are 15AH. I set the battery as Li Ion as this gives a HVC of 4.1 v per cell not the 4.2 of LiPos but it will extend the life of the batteries quite a bit. the ichargers can be set to LiPo and have their LiPo HVC altered in the settings this allows for 4.15 per cell Gary's HVC of choice.
to go with these you would need a LVC on your battery for each of the turnigy packs in parallel so that if you have a 10AH pack 20 cell made of 8 turnigy 5 cell packs you would need 4 LVC units 1 for each pack in series the second 4 turnigy packs would be put in parallel with the first 4 packs you would also need parallel power leads to link the battery packs in parallel, sorry for all the guys that have been doing this for a while, if you use the latest cellog8 BMS setup from Gary when it is available then if used on just one battery pack you will have the LVC system built in to the unit but if you use the new cellog8 unit just for charging or use any of the R/C chargers then you will need a LVC, the boards that Gary designed are just the ticket for this, I am trying to take things to the next stage by moving manufacture of the boards to china and making the circuit SMD based so no more self assembly but getting the designs to china is not easy and it takes time to get results back as to how much a design will cost lets hope the price works out ok. gary's boards have a built in parallel balance section that the balance wires from each pack one of mine is identical to Gary's the other has a single input for adding LVC to a custom parallel balance board either will do the job as the LVC circuit in both are identical. it is best if you don't get as far as activating the lvc board it should be there as a safety net not really needed 90% of the time but just every so often on long rides you will go outside the batteries range it is then the LVC will save you from having a firebomb next time you recharge, if your LVC is always kicking in and you are no where near your battery is always Wh limit then you probably have a bad channel if you have the LVC cut in every time on your normal ride and you are close to your the max Wh for the battery then you need bigger battery.
this should make for safe LiPo system.
Geoff

 

[recumbent]

Yep, My 6 packs of 8s Turnigy lipo's are also waiting for an easy hook-up solution.

And the money's in the bank.

Guess it may be for this winters project, which is fine because my old LIFePO batteries are still working fine.

 

[johnrobholmes]

This would be a better thread for discussion of bms and charging dilemma we face http://endless-sphere.com/forums/viewtopic.php?f=14&t=21017, or maybe there is another thread floating around that I didn't find.


I'm going to up my pack to 18s 4p, and that is a lot of cells to manage!

 

[geoff57]

Hi
I have brought another member of the ebike community into the LiPo fold, he used to ride with NiMh and second hand Li Ion battery packs. I got him to start off with a 10s 4p pack not that high a voltage I know but it gets him going faster and at a more sustanable speed than he has ever done before. for LVC he has a pair of BM6 monitors until I get the micro LVC's made. For a charger an Icharger 3010b was chosen as it can charge 10 cells at the same time, not the cheapest of chargers and at the moment the pack needs to be split to charge as the power supply is not powerful enough a 14V 25A PSU a pair of big SLA batteries are on order waiting for pickup along with some SLA trickle chargers, that should make a good enough power supply this is a simmilar power supply to the type LFP uses.
This may well have a knock on effect to another guy who is into making ebikes, after seeing the improvment in my friends bike he is thinking very strongly of going LiPo as a power supply for his bikes, but we will have to address a few things first, quantity is going to be bigger than could be bought through hobbyking looks like going direct to turnigy might be the way to go on that one and there is an easy way to get them here if we can make a deal. a good quality reasonably cheap charger will be needed as well the Ichargers are ok for a one off but not for mass orders we may look at Garys latest offerings for that one maybe as an onboard BMS or with an onboard LVC and garys unit as a charger it will depend on how the system is put together and if more than one battery pack needs to be charged from one of these units.

we all wait to see what the second guy will do for now my friend is over the moon, his battery holder can take 4 more turnigy packs and he wants to get them soon.

Geoff

 

[nicobie]

Just a quick heads up...

The zippy flightmax 6s 5ah 25C batteries are back in stock. $45.07 if platinum.

http://www.hobbyking.com/hobbyking/store/uh_viewItem.asp?idProduct=8586

 

[mwkeefer]

Actually that stock alert came last night at 1 or 3am EDT but the site still shows BK as the status, I think it was a misfire as I received 4 or 5 of the emails then about 5:30AM I received an alert on the 170kv 5lb 6000 watt HXT style outrunner.. that is actually in stock.

Customer service said it was a glitch that the delivery hadn't come in (I thought maybe they were filling back orders before making the stock available) and the notice was a false trigger.



-Mike

 

[nicobie]

Hi Mike,

It shows in stock when you click on the above link. I tried to buy 7 and it was going to let me.

 

[GCinDC]

used up 8Ah of 10Ah and hooked up charger. the power supply died (a thankfully peaceful death) overnight in the garage. (bursting caps). two days pass.

i replace psu (350 watt meanwell) and charge, but it sits on balancer for 2 hours. one of my 5 cells in parallel (charging 5s) is still at 4.10 while all the others were dancing up around 4.15/4.16.

i have the icharger set to timeout after 260 minutes. i reset it and it starts balancing again @ 2Amps or so, but after timeout again, that cell is only up the 4.12...

i reset it to continue balance charging and after another 260 minutes, it gets up to 4.14...

it's never taken this long to balance before. i hope i don't have to post again with worse news...

 

[El_Steak]

The easiest way to bring back a cell is with a single cell charger and a little adapter like this one Ypedal made:

http://endless-sphere.com/forums/viewtopic.php?f=14&t=20402&p=298267&hilit=lipo#p298267

I made an adapter just like that and bought a 2 amps 4.2V cell phone charger off ebay. Just plug the charger in the low cell and only that one will be charged.

I also made a little discharge rig using a couple of 12V 50w halogen bulbs that I can hook on a specific cell using the same adapter. Discharges really quick. I unfortunately blew both my halogen bulbs when I mistakenly plugged them on the full pack (100V in a 12V bulb is really bright... for 1 second... )

 

[johnrobholmes]

Got another 7 5ah 6s 25c packs in last week for a buddy. All were very well balanced and in good condition. The box was thicker than usual, but there was still a lot of free space in the box.

Buddy has been riding his 6 packs (18s2p) for a couple of days now. Lower voltage than the 24s a123 it replaced, but keeps the same speed and is easier for him to charge.

I have some capacitor BMS boards coming, along with a 600w bulk charger. I will see how they all work together shortly. Hopefully it will make 18s packs easier to manage. I am tired of charging three packs so that I can go out on the fast bike.

 

[GCinDC]

Got another 7 5ah 6s 25c packs... The box was thicker than usual

Just one box? Seems like I can get 5 5ah ones in an order for EMS shipping...

And seven because you want one spare?

and, got a link for the 600w bulk charger?

The easiest way to bring back a cell is with a single cell charger and a little adapter like this one Ypedal made...

took me a minute to figure that out, but YEAH, that's great. just got to remember not to charge at 10A...