Victpower A123 20AH 48volt battery pack

[ohzee]

those are 75's and yea no gender gotta watch where it goes / color.

 

[RayGo]

Thanks for all the great info on this forum. Glad you seem to have had a good experience with Victpower. How good was the packaging for your shipment?

I was about to buy a 36V15AH Headway Lifepo4 battery pack with 40152 cells for $380 with free shipping. I changed my mind after reading on these forums about the A123 AMP20 cell packs. I read all 37 pages of the topic - "Group Buy? Dr.Bass Steveo found 7s3p Module! Awesome Price" as well many others. I wasn't sure I wanted to build my own 36V20AH A123 pack so I checked with Victpower last night on an assembled pack.

Victpower quoted a 36V20AH AMP20 pack for $285, 43.8V3A charger? for $33 and a custom steel case with handle for $36. I was not able to get more details on the charger. The steel case is 90mmx165mmx240mm and weighs 1.5kg. However the case is what I like to protect the pack during shipment and could be mounted on my bike. I was concerned since mikebikerad posted back on Sept. 21st that his two 26V20AH packs were both damaged in shipment.

Now the bad news. The shipping is $182.50 using TNT since they say HK EMS DHL will not ship the battery packs. So if your battery pack works, this is a good deal. If the pack is damaged and even if the warranty is honored, I'm assuming you will have to pay the $182.50 shipping for the replacement pack. Worse case would be having to also pay the shipping to return the damaged pack.

So now I am undecided again. I do want an A123 AMP20 battery pack. However, ordering the assembled pack from Victpower is hit or miss. Now I'm debating my own build using the kit from agniusm and the cells from John in CR. Cost will be about the same for the build versus buying from Victpower. Any suggestions?

Also, how do I get a hold of cell-man? I checked his emissions-free.com site but there is no info on the A123 AMP20 packs, only the older 26650 cells. Thanks again.

 

[redstone02]

Thanks for all the great info on this forum. Glad you seem to have had a good experience with Victpower. How good was the packaging for your shipment?

So now I am undecided again. I do want an A123 AMP20 battery pack. However, ordering the assembled pack from Victpower is hit or miss. Now I'm debating my own build using the kit from agniusm and the cells from John in CR. Cost will be about the same for the build versus buying from Victpower. Any suggestions?

Also, how do I get a hold of cell-man? I checked his emissions-free.com site but there is no info on the A123 AMP20 packs, only the older 26650 cells. Thanks again.

Got photos at work of the shipping box... typical... they only played tag football with it; not tackle.

Cell-Man = emissions-free_worldwide@hotmail.com
Drop him a line for a quote and post up here (if you like or PM me).

Just ordered a few items from DigiKey, including connectors for a wye adapter for CellLog connection/BMS/cell balance connections. Will not be able to log cell data for another week. But this weekend the load bank will be complete. With a Watts-Up meter I hope to get overall discharge data for the pack.

Thanks,
Tom

 

[redstone02]

And what voltage does the charger put out ?

charger output = 58.6 volts
Within toleratance for a 16S A123 20AH pack?
I guess with your questions there is not a voltage regular or any other power conditioning in the BMS...

 

[redstone02]

First problem....

http://youtu.be/UG9Xxx0jq28

I guess I'll find out how good the one year warranty is...

 

[999zip999]

Dnmum is the answer man for that.

 

[RayGo]

Just saw your video on youtube. Hope you find an easy solution like a loose wire connection without having to tear apart the pack.

I was just e-mailing Wang Xin at Victpower for more details about their 1 year warranty. I'll keep you posted.

By the way, what do you think about their charger for your pack? They had no specs on the 43.8V3A charger they recommended for $33. I'm thinking about a 38.4V6A smart charger that another member recommended.

 

[agniusm]

Those packs from victpower look bloody awful. Anyone at home can do a better job. I would go with cell-man pack even if it was cylindrical cells.
Those packs are fine example of a bad Chinese product.
We still don't know method on method victpower is using to serial these cells. Mind that if they are welded or soldered, replacing cells would be hard task and who knows how they will perform, leaving a question if the tabs on cells used in this pack are cheese like aside. I always lived by the rule that you cant buy quality products cheap.

 

[redstone02]

Just saw your video on youtube. Hope you find an easy solution like a loose wire connection without having to tear apart the pack.

I was just e-mailing Wang Xin at Victpower for more details about their 1 year warranty. I'll keep you posted.

By the way, what do you think about their charger for your pack? They had no specs on the 43.8V3A charger they recommended for $33. I'm thinking about a 38.4V6A smart charger that another member recommended.

I have not opened the cover to the charger. Through the vent holes I see components glued in place. Cannot see the values or manfactures name on the caps. I have not wieghted it but feels substantual. Fan is loud but that does not bother me.

 

[redstone02]

Those packs from victpower look bloody awful. Anyone at home can do a better job. I would go with cell-man pack even if it was cylindrical cells.
Those packs are fine example of a bad Chinese product.
We still don't know method on method victpower is using to serial these cells. Mind that if they are welded or soldered, replacing cells would be hard task and who knows how they will perform, leaving a question if the tabs on cells used in this pack are cheese like aside. I always lived by the rule that you cant buy quality products cheap.

That crossed my mind but figured the cells would be of the same quality I would use if I bought your kit (unless you know of other A123 20AH vendors). My setup is only ~20 ampere setup with GNG mid drive with stock 20 ampere controller, not enough to warrant your high performance kit... at least that was my thought process.

 

[redstone02]

Those packs from victpower look bloody awful. Anyone at home can do a better job. I would go with cell-man pack even if it was cylindrical cells.
.

How many packs have you seen from victpower? How many threads did you find using a search of the site?

I only found one and that one did not look that bad... not perfect by an stratch... but very usable.

 

[dnmun]

this pack is dead from the factory?

 

[redstone02]

this pack is dead from the factory?

A qualified not DOA.
I do not have my load bank finished, that is my weekend project. The best load I have at this time a 250 watt 120 volt heat lamp = ~1.0 ampere load. I ran this load for about four hours in order to allow the BMS to bring cells into balance.

The load bank will (hopefully) qualify a fully servicable battery pack. The load bank will have a max load of ~20.0 ampere in 5 ampere stages.

To All: Thanks for all input, good or bad.

Kind Regards,
Tom

 

[dnmun]

how does discharging the battery bring the pack into balance? what is the charging voltage and what do the cells measure while on the charger?

 

[redstone02]

how does discharging the battery bring the pack into balance? what is the charging voltage and what do the cells measure while on the charger?

I'm a total n00b at this, my thought was to bring down the total charge for pack = no cells would be top charge. The discharge would not bring cells into balance but allow (at least in my mind) the BMS to do a better job of balancing... maybe not (?).

Should I have the pack on the charger regardless of the state of charge? Leave the pack on charge overnight regardless of the initial state of charge?

Thanks,
Tom

 

[999zip999]

Balance I would like to see the voltage pre cell to see the balance of the pack even how balance these packs are before charge. I wish they had an extra set of sense wires. Perfect balance is the ideal goal. So ?

 

[dnmun]

if you have a BMS to balance the pack then you have to leave it on the charger balancing. what are the voltages while charging? that is what you should focus on. if you have an ammeter then run the charging current through the ammeter so you can keep track of how much current is flowing during the balancing.

 

[redstone02]

Balance I would like to see the voltage pre cell to see the balance of the pack even how balance these packs are before charge. I wish they had an extra set of sense wires. Perfect balance is the ideal goal. So ?

I will post what I find re: cell voltage and rate of discharge. I have an order with Digi-Key for connectors allowing two CellLog 8S to be "wyed" in between balance (or sense) wires and BMS.
That might be first of next week.

I will measure cell voltage tonight with DMM and post up if you like.

Regards,
Tom

 

[999zip999]

This will help you now and follow the state of the battery. As what's up.

 

[ohzee]

If you are careful and cut off the blue plastic over that BMS whatever is going on should be pretty obvious.

Just looks to me like something does not have a good connection. Also if you showed people what the BMS looked like
they could help fill you in on how it works tho most are about the same.

Anyway dnmun is who's advice id follow. I am just one of those guys with a little bit of knowledge and a bit dangerous.

hope you work it out.

 

[redstone02]

Here's a couple of videos of the pack:

http://youtu.be/_xINWhdeOJQ

http://www.youtube.com/watch?v=FahRnAEWB1A&feature=share&list=ULFahRnAEWB1A

 

[dnmun]

don't be adding more connectors and especially not something that is connected to a load. you don't know much yet so you could screw up bad.

just put the battery on the charger and charge it until the current drops to .1C. then read the voltages on each cell where the sense wire plugs into the BMS. in fact measure as much as you can. measure while ON the charger. what is the charger output voltage?

 

[dnmun]

from pm, "My plan was to "wye in" connectors for Celllog 8S. The balance wires would connect to the BMS as they are configured now. The "wye" would simply connect to two each CellLog. Would this be a problem?
redstone02
1 W"

the cellogs will consume power from the battery. you do not need them to measure the cell voltages, you can do that easily with the voltmeter. if you are cutting open the sense wire to add another wire in parallel you run the risk of shorting them.

you do not have to constantly know what the individual cell voltages is if you have a BMS. but if you are having trouble balancing the pack then you need to be measuring the voltages while the pack is charging.

i still don't even know if your charger puts out enuff volts to balance the pack. don't know the cell voltages. that is all you need, all this other stuff is wasted time and money, imo. plus the risk that it will create more problems you cannot handle.

 

[999zip999]

I would Like sense wires but wouldn't cut the pack to put them in I mean at time of order if I spoke chinesse. I wouldn't T into the sense wires. Cell meter's off balance a pack if left on. I unplug everything to be safe. But this is a hobby now.

 

[redstone02]

from pm, "My plan was to "wye in" connectors for Celllog 8S. The balance wires would connect to the BMS as they are configured now. The "wye" would simply connect to two each CellLog. Would this be a problem?
redstone02
1 W"

the cellogs will consume power from the battery. you do not need them to measure the cell voltages, you can do that easily with the voltmeter. if you are cutting open the sense wire to add another wire in parallel you run the risk of shorting them.

you do not have to constantly know what the individual cell voltages is if you have a BMS. but if you are having trouble balancing the pack then you need to be measuring the voltages while the pack is charging.

i still don't even know if your charger puts out enuff volts to balance the pack. don't know the cell voltages. that is all you need, all this other stuff is wasted time and money, imo. plus the risk that it will create more problems you cannot handle.

Thank for the detailed reply. The CellLog would be used to measure each cell discharge and create a performance curve for each cell to revil weak cells. The BMS on the pack has two connectors: one with 8 pins the other with 7 pins. Using JST-XH connectors for an "OEM" wye. The connector would only be used for CellLog monitoring. To avoid possible ground path problems with battery charger connected the CellLog USB connection would not be used until the CellLog was removed from battery pack.

Do you think this would create a problem?

I did probe the balance wire connections on the BMS and will post details later day.

Thank you again for your helpful input.

Kind Regards,
Tom