Cheap eBay winforce lipo

[Scottyf]

Evening all,
Just to let you know my cheap lipo from china arrived today.
So tonight I have been soldering up the below ready for the first test run tomorrow

Which is basically a 3 parallel 44.4v wiring harness using deans connectors.
Don't worry it's all shrink wrapped and tested. I just put insulation tape round as an added insulator.

The batteries are 6s 5200mah 22.2v 20c rated lipo. In the rc world these are not rated that well as they never seem to hit the capacity or deliver the huge c rating most rc hobbyists are after.
However I am hoping that in an ebike application with a low current draw these will perform very well.

They where £30 each delivered. Which is about as cheap as it gets without ordering bulk from hobbyking.
Ordered on the 01/11/2011 arrived at my door 09/11/2011.
Very fast air mail.

Cells all arrived at 3.9v +~0.2v so happy with that.

Will review when I've used them a few times. But I'll be paralleling them with 2packs of turnigy and 2 packs of zippy lipo. Each have much thicker discharge wire. But again I'll only be pulling 20amp max from a 15ah pack.

 

[cwah]

Any link from the seller?

Just to know who are the good and the bad guy

 

[Scottyf]

As requested
Link
22.2v 5200mAh 20C LiPo 6S 22.2 Volt RC Akku Battery WF | eBay

Seller
RC Parts, LED Light items in GoMarketStore store on eBay!

 

[piotrmacheta]

I've been using these for about a year now and they do work OK but I found that the 20C did not supply enough current unless paralleled to a 10Ahr pack. I also got some 30C (from go-market on ebay) and they work better and I made a 5Ahr pack for 12 mile range. The only downside is charging the individual packs separately using a ballance charger is a bit time consuming.
I have some of the 5700mAhr 20C packs which they don't seem to have anymore. In a parallel connection (11.4Ahr declared pack) I managed about 10.5Ahr.
As you say one of the cheaper ways to make up a pack but you do need to charge separately so a bit of care required. I use a Lithimon to alarm when depleted.

 

[piotrmacheta]

Just to add, the 5Ahr pack is perfect as a 'fuel reserve tank' - ie I have it in a bag on the bike and never use it unless my main battery runs out therefore I'm never stranded or have a bit more range if I need it. It's light enough not to worry about.

 

[Scottyf]

You can bulk charge if you really want to by buying something like :-

EBike Charger for Lithium Ion/LiFePO4/Lead Acid Battery

Then you can specify the voltage and current. The higher the values the more it generally costs. But can be a cheap quick way to bulk charge a pack in an hour to 4.15v giving you more or less 90% of your range without risking the balancing.
Espcially if you parallel the balance taps.

I personally dont do any bulk charging because I have a paraboard and it takes me 2 mins to remove the cable i've made above and plug it in.
The only time I would bulk charge is if I go over the 6 batteries or have lots of lipo in a setup like a motorbike / or very fast ebike that would use lots of batteries.

In theorey I should be able to balance charge the full pack from empty in 3.5 hours using a 200watt basic lipo charger. Which is acceptable. Any more though and i'd want to purchase a 500w charger to bulk it.


Anyway. So far I used this morning 4.8ah (not pedalling very hard at all to be honest) as I wanted to discharge the batteries (I normally use 3.2 to 4.2ah same run) and all the cables have worked and nothing appears to have died.

The cells are currently reading 3.92v each so seem to be balanced nicely with the rest of the lipo which i'm happy about. Hopefully I can knock another 5 ah out tonight on the run home. This way it will give me a few nice cycles for the weekend.

The current draw is now 1.3c rather than 2c. Making the life on the batteries hideously easy.

I also got some 30C (from go-market on ebay) and they work better and I made a 5Ahr pack for 12 mile range

I think they would really as the cells are better quality. But in a 5ah pack using my setup I used the Zippy and turnigy packs and they worked very well even though I pulled 4 to 5c from them. I'd imagine these 20c PEAK, 15c continous would struggle. But in the setup I have now i'm giving them a very easy time.

 

[Deleted member 4366]

I also have a 5.2aH pack as a reserve battery. and so does my friend Steve I changed all the connectors on my batteries on all bikes to Deans so that I can swap batteries between bikes or use one on a rack as a reserve for another. When I use the 5.2aH pack as a battery on it's own and use full power (20A or more) the voltage does sag quite a bit, but it still gives the amps. When two are used in parallel to give 10.4aH, the sag is hardly noticeable.

 

[Scottyf]

Maybe the batteries should really be rated at 15c with a continous of 10ah.
There an interesting size being thinner yet slightly longer and taller than the turnigy packs.

The size makes them feel quite a bit smaller. Although in volume i bet there is no size or weight difference.

 

[cwah]

Thanks for the link scottyf.

The price seems really interesting.

I purchased these lipo:
HobbyKing R/C Hobby Store : ZIPPY Flightmax 8000mAh 5S1P 30C

They are much more expensive and I may have to pay taxes. Maybe I should look at cheaper lipo

 

[piotrmacheta]

Like the paraboard idea but isn't it a pain to make/break all the connections each time? The bulk charger is the easiest (with an occasional ballance charge to keep all the cells matched) but I use 13 and 14 cell LiPo packs and can't find a bulk charger that will do this.

 

[Scottyf]

Depends how lazy you are really and how much of a plug and play system you need.
I guess it is more difficult than pluging a charger in and then turning on.

But i'm hoping in the long run the cells have greater life becasue of it. Not saying that is fact but it takes 2 mins for me to remove the batteries from my back pack which is foam lined and connect the batteries to the para board. It really doen't take that long. Maybe a minute longer than if I was to bulk charge.

least this way I know there all parallel in connection and with the charger won't go over the 4.2v limit.
Like I said if I had more batteries then I would really think about creating my own bulk charging harness with balance wires.

It took me about 40mins to create the above harness. I've got plenty of wire from maplins and could make up my own charge harness. But at the time the para-board made life a bit simpler for a £10.



If you after bulk charging 13/14s you could get something like this :-
350W 48V 7.3A Regulated Switching Power Supply New good | eBay

Which you can select the voltage output from 41v to 56v.
Giving a max of 4v on your 14cell lipo setup.


Or BMS battery with my link above and you can select the amount of voltage you want and then buy the correct wattage you'd like to chuck though at the lipo. Least with the meanwells or copies you get to choose.

 

[Deleted member 4366]

There's also this one, which has a voltage adjustment pot inside, or BMSbattery will do it for you if you tell them the voltage you want.
Alloy Shell 400W LiFePo4/Li-Ion/Lead Acid Battery EBike Charger - BMSBATTERY.

 

[Scottyf]

Just a quick Update.

I've now done roughly a month's worth of cycles on the lipo which is probably 20 half cycles.
I usually use up 6-10ah on my commute depending on wind / pedal power.

The packs are still nicely in sync and balanced. I've had no problems with the connectors and they appear to be performing with no issues. As my ebike requires 23amp ish max peak its only roughly 1.2C rate on the cells so there being given an easy ride.

To cycle them a few times I just hooked them up in series (the winforce) and road a good 10 miles to drop them down to just under 3.7v.

As far as capacity goes on my commute now I normally get back with each of the cells at about 3.8v each.
So plenty of capacity still left in them (44v 15ah).
The winforce pack voltage is always slightly higher than the Zippy and Turnigy packs by about 0.20v.
Which would seem about right as they are newer and rated at a slightly higher capacity (5200mah vs 5000mah).

Although I suspect the difference in pack voltage is more due to age rather than rated capacity.


All in all very impressed and for an ebike application work very very well.


If you manage to get a BMS with these lipo you could have a very safe high discharge, cheap battery.
It would also be a damn sight easier to build than 18650 cells.

 

[piotrmacheta]

Great to see it was a success. Can you judge yet what the real capacity of the 5200mAh pack is?

 

[Scottyf]

I've got the software on my pc for analysis. I will run a few cycles with data on the discharge to test them.

 

[Scottyf]

Hello All,
I've had chance to test these right down to critical levels. Its quite apparent that the cells are no where near as well matched as the turnigy or zippy packs at similar ratings.

I've been pulling 3c out of them lately and really pushing the capacity of the cells. Its finally shown up a weak cell in doing so.

Cell 4 in one of the winforce lipo pack has sagged badly when pushing the capacity and done the old Lipo voltage dump to below 2.8v.
Its also become a little puffy and created alot of thermal reaction.

I've used these packs for about 60 cycles and only 2 of them have been deep discharge levels.
In comparison then running them down here is the read of the other cells :-

Conclusion
As above none of the packs are in parallel when in use. It appears that theZippy and Turnigy packs stay more in balance even to high rates of discharge and high Depth of dischage (DOD).

The poor Winforce on the same platform just dont appear to have the same Capacity. The C rating does not appear to be the issue. The so called 5200mah is no where near correct.

These cells safely have about 4400mah so shy 800mah compared to whats written on the packaging.

I've nursed the puffed cell back to life. But now charges much quicker than the other cells in balance mode and will not balance correctly. It wants to peak much quicker.
I've used it this morning to see how it performs and its about 0.8v lower than the other cells.
Its definetly damaged it taking it that low.

I will be disposing of the cell accordingly. I will be making up a 5s pack or maybe a 3s booster pack for an emergency 12v battery. However I will no longer use that cell for Ebike applications.
I've since brought another 6s pack to replace is at £30 delivered.

Here's some media of the cell...

 

[Scottyf]

http://i558.photobucket.com/albums/ss30/scottfarnham/4488c251.mp4

 

[hech]

Thats very interesting Scotty. Those winforce batteries seem to be about the cheapest around so its good you can give us a good critique. I didn't realise a 6 fet controller could take as much as 44v - the capacitor is rated at 50v max isnt it?

 

[Scottyf]

I have a lyen version. It will go up to 100v if I arrange the lipo pack in that way.

Its a recent investment I've purchased. But pricey none the less. You can take cheaper controllers and buy better cap's / mosfets and change the resistors to allow higher voltages much more cheaply.

But you'd need a steady hand a good soldering iron and skills to do it correctly.

Its also programable.


Thank you for the encouragment on the review.
There a good battery for the value cost. There rubbish for super power hungry applications. But for run of the mill low C rate extra batteries you can't go wrong.

The Turnigy / Zippy packs are better. But they generally cost £40-50 each depending on how many you buy in one go. As ever shipping is the bigger deciding cost.
If you can get them cheaper then buy them.

If you dont mind running extra packs to make up the capacity in winforce Lipo. Then go that route. It really depends on the applciation and use. Like much with Cell Technology.

Its all decided on its intended purpose that defines what you get. Cost should be second.

 

[piotrmacheta]

Thanks Scottyf, really good info. I've also had a few issues with my 30C 5000mAhr packs in that they now sag badly under load but I have been pulling up to 20A and routinely about 15A from them (linked up in series) - probably only about 50 cycles used. Also 4500 mAhr seems about it.
Like you say I think they are OK if you parallel them up but not a long life in series.