found new cheap site for BMS, LiFePO4 & charger up to 18000W

[BatteryMooch]

Pics of the ecitypower 48V BMS custom upgraded to an 80A current limit.
Unfortunately my camera can't do better close-up shots, no macro mode.

It looks like the 14-pin chip's number can be read on your unit. Could you do me a favor and use a bit of body oil and rub it on the top of the chip to make the scratches disappear? Just rub a fingertip on your forehead a bit and then on the chip. You might need a magnifier, but you will probably be able to read the chip numbers.

shinyballs, there's a small chance that might work on your 14-pin chip too. The "ink" might have been rubbed off but perhaps there's just a tiny bit of the indentations still left in the epoxy body of the chip. Tilt the chip in many different directions under a bright point light source and use a good magnifier or loupe. I've often used this method to get numbers off of chips that look completely sanded clean.

 

[julesa]

Good trick! I can't see anything with my naked eye but I'll dig around and see if I can find a magnifier. There should be another digital camera somewhere around here too, with macro mode.

EDIT: I still can't make out any part of the number even in bright light with magnification. Thanks anyway.

 

[shinyballs]

I'm an electronics noob, I'm a lot more comfortable building email systems. But you gotta learn somehow...

same here...
I can only identify this one, the other 4 bigger parts were scratched clean.

 

[BatteryMooch]

Darn.
I was hoping for at least a partial number. We might have been able to tell then if it was a PIC or a bunch of logic gates/comparators/whatever.
Thanks for checking though!

 

[shinyballs]

Example for using only 15s, how about wiring it ala r/c balancer, by not using the 16th positive pin?

 

[ecitypower]

I am Jack Xie from ecitypower. My Chinese name is Fangqing Xie. Ecitypower is our factory. BMSBATTERY is our online shop. Welcome to ask me any questions! I will try my best to answer correctly. It is my first time to come here.Hope to make friends with you all,not only business.Thank you very much!

 

[Sacman]

Hello Jack,

Welcome to the ES Forum. What a coincidence...you dropped in to make your first post here because I was just about to give a report on your service to the rest of the group. And it's actually a favorable one for you. Here it is...

*******************
17 days ago I ordered 2 chargers (Model EP-A 400watt in 87.6V 4A version) from Jack Du at ePowerCity.com. Jack emailed me after he recieved my payment by PayPal and said I would get the chargers in 10 days.

After 10 days I emailed Jack and asked for a status on the charger because I had not recieved them yet. Jack appologized for not informing me sooner that when he recieved my order, they had just decided "to produce new chargers" and the few pieces they had on stock did not pass QC so nothing was sent yet. He said that QC is important because he didn't want unsatisfied customers, especially those ordering from PayPal. He said the chargers would get sent off as soon as he has some that would pass QC. I thanked him for his reply and appology and told him I would wait.

Three days later Jack emails me and says he just sent off the parcel of 2 chargers that just passed QC and another 3 days later I recieved the package. Whoa! Three days is pretty quick from Bejing, China to me in Los Angeles, USA!

Suprizingly, the packages looked professionally packed with plastic bubble pack and even a 1 page user's manual written in English (much nicer than any batteries or other chargers I've recieved in the past from China).

And another surprize was that these chargers came in a decent looking aluminum cases like the ones shown on their website. I say that because I supposedly ordered the same exact chargers that pwset got and posted earlier on this thread and the chargers he got came in black plastic cases instead of aluminum.

HERE ARE PICS FROM THE WEBSITE:

HERE ARE PICS OF MY CHARGERS

The label even shows proper output (87.6v 4A) .The only oddity I could see was that the model number on the label is shown as "KP9004AL" whereas I supposedly ordered a Model EP-A. If you look closely at one of the images from the website you'll see the brand name "KingPan". I guess that's where that KP model number came from.

Well I've yet to still test these chargers but I can't until I put together the 72v LiFePO4 packs. But so far I'm happy with the service and delivery from Jack at eCityPower. I'm glad to say that prior reports on his prompt and professional communication seem to have been true.

 

[Ultraman]

My 36v/15ah battery and two chargers arrived today, 7 days transit from China. Things look good so far. Pack was sitting at 38.9v when opened. Packaging was adequate. The battery itself looks to be constructed identical to the photos posted earlier in the thread (shrinkwrap, memory foam). I haven't pulled it apart to test individual cells yet and don't think I will if it works out OK for the first few rides. One charger had a North American plug and one a Euro plug, not a big problem. So far, Jack and ecitypower have worked out well for me.

 

[Achim]

Today I did 59kph on the flat thanks to the delta wye mod I did to my 9C, using the 48v 10Ah battery from ecity!! Yehaa, I love the speed! And the battery held up to it! Was just warm after 10min full throttle, starts and stops, but the controller was hot!

Great to see you here Jack!

 

[Ultraman]

I like the way my 36v/15ah pack performs, having nothing to compare it against except SLA's in my e-scooter. The longest ride so far was 15 km, avg speed 30km/h on my 9-Continents front hub from e-bikekit (700c, 200lb rider, Specialized Cirrus hybrid). I'm trying to be easy on the throttle from a dead start and peddaling just enough to look like I'm still riding a bike, and using 10.5 watt-hours per km according to the Cycle Analyst. The pack was still at 39.4 v after the ride. So far I'm using the 1.8amp charger factory-set to 41.8v.

My Jack Pack stacks up, Mack.

 

[caleb7777]

I destroyed one cell by poking the battery pack and had to remove it. I think I can use the pack still with one less cell but the tabs coming off of the cells do not appear to be solderable! I didn't try a torch but I could not get it to take solder. My guess is that they are aluminum tabs. How do I attach to it?! I need to get a heavy wire onto it. Any ideas? Is there a different solder to use? Easy solution anyone?

 

[caleb7777]

This style cell with tabs out sides, you can't really see it

 

[dnmun]

not sure what you are asking, the positive anode appears to be lithium on mine which is crimped onto a tin plate tab which is soldered onto the spreader at the top of the pack.

your battery in that picture looks intact. is this before you put the screw into it?

 

[caleb7777]

That is the old pack but same cells.

I destroyed cell 1.

I want to run the BMS at 15s now.
I got it reattached, sorta without the last cell but the BMS appears to cut the power.
What needs to be done for the BMS to run at 15s?

Other questions: Can I increase the continuous discharge current? Does anyone know what this BMS is rated for continuous. It is different than the first I received and I don't know which is the high output.

 

[Sacman]

Topic of discussion has taken a complete tanget away from original post.
Might be better to start another thread Caleb.

 

[BenMoore]

caleb, if you can't get the discharge max from the manufacturer you would have to use a current meter and observe the limit that the BMS allows under load.
To increase the limit of the BMS you can partially solder the shunt to reduce its effective length/resistance and thus trick the board into allowing a higher max current. Doing this will of course increase the heating of those unidentified FETs. They could probably handle small increases without worry and heat sinking them would buy you more room again. If they blew you could replace with a higher current rated FET at little cost. Be sure that any new current capability is within the specs of the cells however, otherwise their lifespan will suffer.

 

[docnjoj]

This seems like an important topic and should have its own thread. I would very much like to learn how to "downsize" a BMS if some cells fail!
otherDoc

 

[caleb7777]

Thank you Ben

Come join me everyone, help is great!
http://www.endless-sphere.com/forums/viewtopic.php?f=2&t=10910

 

[HAL9000v2.0]

I just recived bms and chargers from bmsbattery. the shiping price was too high 68$ but it came in 11 days. Nicely packed no visual damage but also no invoice an no plan how to assembly. I will probbably do it right but half of paper with some shematics do not cost much. Also it stated on the site that current limit is 80A, but I have only 2 shunt wire and 3 fets ??? I saw in previes posts that 80A pack have all?

 

[Eric]

I purchased the 45 amp model, BMS-16S-45AR, which is supposed to handle 45-75 Amps. Mine has 4 FET's and 3 shunt wires. It looks like you received the BMS-16S-20AR (20Amp) model.

As for a hook-up diagram, look earlier in this thread for the diagram they sent me. It should apply to your BMS as well.
Eric

 

[caleb7777]

Jack has new price list apparently here:

He has motors listed hmm... expanding
and custom made battery boxes

 

[adrian_sm]

Wow.

US$70 for a Bafang QSWXH (8FUN) + Shipping

 

[adrian_sm]

On a seperate note I recently received a total of 8 cheap US$12 2Amp chargers, for me and my mates.

Took a while to arrange the order, as they were out of stock. Then I had to chase them a bit to place the order. It might have been slowed down a bit because I did ask for a special, 4 cell charger for a mates booster pack, which was a non-standard voltage for them.

Jack/Fangqing was quite thorough in ensuring we agreed on the charge voltages and charger format, before the order was placed.

The transaction all occured via eBay. With all the chargers, and the agreed shipping price being bundled up in to a single eBay item.

We recevied 7x EP-2A chargers @ 48V (58.4V CC/CV @ 2A), and one special.

All chargers worked fine. Except one that had a low non-load voltage. A quick email and trouble shoot resulted in a replacement being delivered in quick smart fashion.

The only weird thing with the charger is that the voltage from the battery will turn on the light as if it is charged, when you don't have the mains power on.
This caught me out one day, as I plug it all up to charge, saw a light on and assumed it was all okay. Then later thoguht,"Hang on. The light was the wrong colour." Then discovered this weird behaviour. So in future I will make sure that the power is on at the wall, and the light is the right colour before walking away.

Overall very happy with the transaction. It wasn't fast but it was definitely cheap. Only time will tell how the chargers last. But so far so good.

Now it looks liek they will be selling full kits, I will be tempted to give them a go.

Now I just need to convince the wife she needs an ebike

 

[Julez]

Hi!

I just wrote them a mail with various questions concerning the EP-J charger, concerning the adjusting of the voltage and such.
If the answers are good for me, I will purchase it.

Thanks for the threadstarter to find this company.

Cheers,

Julez

 

[caleb7777]

I just ordered the Ep-J also. The plastic ones that are cheap are crap. Mine fried and So i am trying one of his steel ones. When i bought a bought my battery pack he gave me plastic one cheap. Don't do it. Upgrade.