Anyone have an opinion on these batteries?

[borschelrh]

http://www.amazon.de/Fahrradakku-Ersatzakku-LI-Ionen-Zhenlong-Prophete/dp/B009NTGUBC

I searched though the threads but can't seem to find these on ES. I am sure someone has mentioned them somewhere I just can't find it. I have found a guy who will sell me 2 for 160 Euros new. But, are they actually any good? I need 36V for Gen 1 GNG mid-drive. I was thinking to build a pack myself but if this type of pack is minimally okay I will go with these instead. If not then I will build a pack using LiFePO4 cells. Anyway, if you know anything about these I appreciate your opinion.

Thanks

 

[dogman dan]

Impossible for me to say by looking at a picture. But in theory two of those connected in paralell would be a nice 36v 20 ah pack. Just one by itself would be ok for lower powered motors, so two should be able to do 1000w or so easy.

But the price sounds a bit too good? Are they used? I keep saying used batteries are often worth 0 dollars. I bought some at christmas that were. Shoulda know better.

 

[Lebowski]

no charger....

 

[borschelrh]

I feel the same way. The ones on Amazon are new and I think this guy is also using new batteries. What is inside I have no clue. But, the price is perhaps too god to be true. The old saw of "you get what you pay for" usually is very true. Buying packs from HK or other sites are way too expensive for me living in Hungary. I would just buy a Ping pack but with shipping and the 35% customs duty it is crazy expensive. I can build a pack using cells from http://www.ev-power.eu/LiFePO4-small-cells/Lithium-Cylindrical-Cell-LiFePO4-3-2V-10Ah.html for about $207 for a 12S1P (or maybe it should be 6s2P?). Actually, that is another question. They state the nominal voltage as 3.2 volts for these cells but I keep seeing on other threads to figure 3.0 V nominal. I guess it really doesn't matter much if it is 38.4 volts verses 36 volts. Higher is better.

But, then I need to buy a BMS if I build my own pack and for any of the systems I need a charger and balancer. I am thinking that building my own pack is the better way to go? But 160 Euros for 2 packs might just be worth it if I can believe they are good. If not, then I will have to tear them apart, find the bad cells, and repair them. That might end up being a lot more expensive in the end. Secondly, I think these packs are made from Lipo's and are probably not LiFePO4 cells. So they might be a bit less robust and have a shorter life span.

 

[borschelrh]

It seems to be a Phylion XH370-10J http://www.phylion.com/en/default.asp?contentID=33

Model XH370-10J(XH01-370-01-E)

D×W×H 388×113×86mm
Normal Voltage 37.0V
Nominal Capacity 10Ah
Weight <4.88Kg
Internal Resistance ≤100mΩ
Discharge Voltage Limit 2.7V(any cell)
Protected charge Voltage 4.25V(any cell)
Charge Voltage Limit 42V
Max Charge Current 2A
Max Discharge Current 19A
Nominal Discharge Current 10A
Charge Method CC/CV(matched charger)
Capacity@1c rate ≥9.5Ah
Cycle life 500times(cycle@RT,1C rate,100%DOD)

 

[SamTexas]

Most of time, a used battery is worth nothing. Especially when bought from a sleazy seller who knew for a fact the battery cells are defective (because he destroyed it by overdischarging when he stupidly put it in series with a larger capacity pack) yet claimed otherwise.

But thanks to the mostly useless and mostly harmful BMS that's included in batteries like this one, these used batteries can be a real bargain. Here's how and why: A few months ago, I bought a used factory built chinese ebike. It has a battery just like the one shown in the first post, 36V, 8.5Ah. The owner said the bike was only a few months old. It was used for about a week and left sitting in the garage for 4 months. He had been trying to charge it for days but the battery just won't take any charge at all. So he told me that I was just buying the bicycle, the motor and the controller. I could have the battery if I wanted but it was no good.

Brought the battery home and just as he said, could not be charged. Opened it up and found out that the 3 last cells' voltage was below 2.1V while the rest (9) are at 3.2V. Used a cellphone charger to bring the voltage of three low cells up to 3.2V and voila, everything worked. The battery charged up fine. I did a capacity test at 0.5C and it was 100% as rated, 8.5Ah.

So while sitting in the garage, the BMS was sucking energy from the last 3 cells, bringing the voltage down to the point that the BMS itself could no longer operate. This is one aspect of the "Battery Murdering Systems". In short I was given a perfectly new battery that appeared to be dead to the poor owner. Thank you BMS.

The first thing I did after that was to remove the BMS and put it where it belongs, the trash can. I added the sense wires, balanced the pack and have been using it since. It has been through about 50 cycles and all cells remain in balance.

 

[SamTexas]

Secondly, I think these packs are made from Lipo's and are probably not LiFePO4 cells.

It seems to be a Phylion XH370-10J http://www.phylion.com/en/default.asp?contentID=33

Model XH370-10J(XH01-370-01-E)

D×W×H 388×113×86mm
Normal Voltage 37.0V
Nominal Capacity 10Ah
Weight <4.88Kg
Internal Resistance ≤100mΩ
Discharge Voltage Limit 2.7V(any cell)
Protected charge Voltage 4.25V(any cell)
Charge Voltage Limit 42V
...

You're correct. The 2.7 and 4.25 LVC and HVC confirm that. It's a LiCo (LiPo) or LiMn (manganese) pack.

 

[borschelrh]

Sam, Thanks, this was my conclusions as well. I had to do this with my Honda Civic Hybrid battery which was mostly just imbalanced cells after 6 years of use. It was a pain but I only had to replace a few sticks. I understand that a trickle charge is sufficient to bring them back to where they can be charged again. My thought is to buy these 2 packs then disassemble them and rebuild it to be 36V/20Ah. I will check them first as I may actually get lucky and they are fine. This guy seems to have a lot of them so I am guessing he is connected with a scooter rental place and these are change-outs. I am not foolish enough to believe they are completely okay. Then I next have to decide how to set up charging. My thoughts are to use an intelligent charger from HK and set them up in 6s configuration. I am not all that sure exactly what I need but the price for these is too good to pass up. I don't mind that they are LiMn batteries. I would prefer LiFePO4 but I may be building a second bike for my nephew who visits us every Summer so I have time to get this sorted out. His grand-parents who visit at the same time are insanely rich (Russian oil) so I am sure I can get them to pay for his setup. He will benefit from my trial and error experience. My problem is my wife who i am sure will scream when she sees how much this is going to add up to.