72V 20Ah Headway pack

[Beavinator]

I have for sale 1 72V 20Ah headway battery pack. It is almost new with only approx 40 cycles on it at absolute most. It has been all re-wired in 10ga wire and is in 2 parts for use in panniers. Comes with a 50A capacitor type BMS. Has 75A Powerpoles for connectors. I want 800 dollars for it plus shipping. I am in Vancouver BC. Also I have a 1500W elcon charger that goes with this battery. For the charger I want 250 dollars plus shipping. If you want both I will do them for 1000.

(moderator edit: post moved to ebike technical from for sale- used, as it is no longer a sale thread:
http://www.endless-sphere.com/forums/viewtopic.php?p=434110#p434110
but should be preserved. All existing posts are locked as is the thread.)

 

[Beavinator]

I guess I should have written this in the ad, the pack is being sold COMPLETE. I will not sell individual cells. Thanks.

 

[999zip999]

headways why are this packs not good for your needs ? Headways ?

 

[skeetab5780]

no pics...lotta dough.. sigh, werent you trying to sell this pack last month with water damage?

 

[frodus]

1000 bucks for a used pack? Good luck on that.

People can get a brand new one, shipped from china, with a BMS, straight from Headway for that.

Even if you spent $100 on the bms, that's still $18.75 a cell..... for used cells.

 

[davec]

too bad you can't split the pack apart to sell the cells- good luck with your sale

 

[Beavinator]

Yup thats right buddy 300 whole km's. And I ordered it Aug 17th. I actually got it in October. I dont know where you came up with this water damage B.S. but it sure as hell wasnt my pack. This pack is like brand new. If your not interested in it then dont buy it, you dont see me going through here badmouthing other peoples items that I have no clue about! As for why I am selling the pack, I am switching to Lipo.

 

[frodus]

If the water damage is untrue, just say so (I didn't see that in your threads either, so not sure where it came from)...... But what we do know, is that you, admitted, to potentially overcharging one of your packs, or at the very least a few cells, and asked about how to bring down the charge. Now, I only see you talk about one pack of Headway in any threads, and one BMS, and one charger, all of which are the same type and model of the pack you're selling. It's safe to assume it's the same pack.


Now, I don't care if that pack is the one you're selling, that is besides the point. My point is, it's overpriced for a used pack of Headway batteries, even if you do include the BMS in the price and it wasn't actually overcharged. Even if they were pristine cells, with perfect charge/discharge, selling them for what you're asking is overpriced.

I won't buy it, but I'll warn others not to pay this much for a used pack. If you don't like that, then don't let the door hitcha' where the good lort splitcha'

 

[Beavinator]

Actually I thought I might have overcharged it but after some investigating that never happened so the pack is in absolutely perfect condition. It is 81V off the charger. Im really glad that you care about peoples money so much! Maybe you should go through this whole thread because there is a whole lot of people on here selling things for more than I feel they are worth. The thing that you people are leaving out of the equation is air shipping a battery pack from china. And it sure as hell isn't no 140 bucks davec. Here is my receipt. Now that I have a look I will sell the pack for 800 bucks, I thought I paid 1250 for the pack.
2 ea. EVA LiFePO4 36V 20Ah battery pack $1,020.78
1 ea. Elcon 1500W HF/PFC LiFePO4 Battery Charger $363.80
$1,384.58
Sub-Total:

$244.40
Shipping (Shipping to CA):

$1,628.98
Total:

 

[frodus]

That is more realistic, and fair. I do go through thread's and look around at stuff. I help a ton of people find things they need, as well as sell them. You're not being singled out.

It's good to hear that you didn't overcharge the pack, and from the sounds of it, you didn't, just that the BMS wasn't letting things charge right.

 

[skeetab5780]

is this not the pack that was for sale a few months ago that had a few bad/corroded cells and a bad BMS? i could swore it was your thread? also didnt it used to charge to 83 or 84v? how is it perfect at 81v off charge?

 

[oatnet]

also didnt it used to charge to 83 or 84v? how is it perfect at 81v off charge?

The nominal rating for a LiFePO4 cell is 3v, resting is 3.3v, and charged is 3.65b A 72v (nominal) 38120s LiFePO4 pack should have 24 cells in series, and come off the charger at 87.6v (3.65v/cell). Some pack makers cheese on the standard, and represent the resting voltage as the nominal voltage, and only do 22s - which would be 80.3 off the charger. I'd wonder if this is 22s2p or 24s2p.

Of course, the pack is only going to charge up to the voltage output by the charger...

$1,600 is a lot to pay for a 48v20a pack - I got 103 Headway 38120s cells for that, INCLUDING AIR SHIPPING from China. I'd suspect that overcoming the inflated the initial purchase price is going to be the biggest hurdle for a buyer wanting to complete this transaction. Perhaps selling the charger and pack seperately would help.

-JD

 

[Beavinator]

The pack is a 72V pack not a 48V. It is made up of 48 cells in a 24s2p configuration. The pack is charging until my BMS shuts off the charger. Do you guys think that maybe the BMS is cutting charging off too soon?

 

[Beavinator]

Skeetab I am going to say this one more time. Please listen to me! This pack does not have 1 spec of corrosion on it and has NEVER had any water in it! I have taken better care of this pack than most people would. After every charge I immediately check the cells to make sure that they are all in balance. That is how I caught it when the 2 balance wires came off. I am not a person that would ever sell somebody an item with any damage. As you probably have seen I had a 12fet controller that I put up on here that I knew worked but it needed to be rewired. As there was a very slight chance it might not be 100% perfect I decided not to charge for it and gave it away for free. I am a very honest guy and if I did sell something to somebody and there was a problem that I never knew about aall they would have to do is message me and I would work it out with them. It really pisses me off when people make it out like Im trying to scam somebody!

 

[Evoforce]

Charger should be charging up to around 88.8 volts(hot)

 

[frodus]

yes.

It should be taking the whole pack to 3.6ish Volts per cell. I bet you have one cell going too high. Let it connect and it should capacitor balance and let the charger come back on. 81V is too low.

What are the voltages of all of the cells?

 

[Beavinator]

Thanks for all the help you guys! Tomorrow I will hook up the charger and measure the cells right after charging and post the results. I will also monitor the cutoff voltage. Thanks again!

 

[Beavinator]

Okay I did a charge and checked the balance lead voltages. Heres the results
1-3.31V
2-3.31V
3-3.31V
4-3.31V
5-3.31V
6-3.31V
7-3.31V
8-3.31V
9-3.31V
10-3.31V
11-3.32V
12-3.32V
13-3.32V
14-3.31V
15-3.32V
16-3.32V
17-3.32V
18-3.33V
19-3.33V
20-3.33V
21-3.34V
22-3.34V
23-3.34V
24-3.34V

 

[Gordo]

Too low. Should be 3.65V when just off the charger. 3.3+V after 24hrs to a week.

 

[frodus]

Gordo,

It's a capacitor balancer. It shuttles charge from one battery to another. We don't actually know how they turn off the charger, and if it keeps it off.

Those voltages are very close to eachother. I bet it's still shuttling charge. They look fine to me.


What we need to know, Beavinator, is what is the voltage that the charger shuts off at? Were those measured voltages RIGHT after you fully charged?

 

[Gordo]

edited on request

 

[Spacey]

My Headway 16Cell 16Ah Pack initially charges to 3.65V but it does not take long for the cell voltages to settle down and lose the initial charge. This is a pack that has not yet gone to the customer so has only had 4 cycles of testing.

 

[frodus]

His BMS is here:
http://www.evassemble.com/index.php?main_page=product_info&cPath=6&products_id=46

Says it's a capacitor BMS, not a shunt BMS. Gordo, is yours a shunt? Because a capacitor BMS charges a CAP with one battery, then discharges it into the next battery if it's of a lower voltage. There is no "shunt".

The cells look equalized just fine (within .03V of eachother). But what Beavinator didn't tell us, is this the resting voltage, or fresh off the charger voltage? If the pack sat at all (even for an hour) the cell voltages can, and will, come back down to about 3.3V.

I'd think at this point, it's got more to do with the charger than the batteries/balancer, but we don't know WHEN those voltage measurements were taken.

 

[Gordo]

removed on request

 

[Spacey]

Charging...well single cell balancing a 12 Cell 16Ah Headway pack at the moment before I let the BMS take over....trying to save a lot of time and damage by BMS over volting the hi cells to compensate for the low ones initially.

I charge one cell to 3.6V then after about 5 mins the voltage really does drop off quite fast......3.6V to 3.47V in 1 hour after the charger is taken off the cell.