A123 AMP20M1HD-A Battery pack kit

[agniusm]

Hi. Blocks will be routed this week, and i hope i will get them threaded manualy till PCB`s will be done. I will comfirm on PCB completion date tomorrow. Rest components accuired. SS bolts will be getting beggining of the next week. cheers

[johnrobholmes]

What are the chances of a few more 24s kits being made? I need two.

[agniusm]

Hi. At the moment i cant tell for sure. I doubt that i will have enough material, possible thou.

Looks like PCB are nearly finished and will be done by Friday. There is slight delay on brass blocks regarding Firm moving to another location but shouldn't take any longer than few days. Rest people who are interested can PM me with what they need and i will have that in mind for the next run. I understand that summer is here and everyone wants it fast. I do all in my power to deliver fastest possible, sorry if i cant make it any faster.

[agniusm]

Hi, received brass threaded bar for end terminals. Blocks should be ready on Tuesday next week and PCB's later today. I thought i will do a vid on tube like a manual on "how to assemble the kit in to a pack" i think it would be more informative than paper manual.
Brass threaded bar for end terminals:

[agniusm]

Making updated list of Kits needed:

docnjoj 2 x 6S kits
ohzee 4 x 6S kits
ambroseliao 1 x 12S kit
Kristoffer 2 x 12S kits
Doctorbass 2 x 16S
totinen 1 x 24S kit

There is 6 x 6S kits available and 1 x 4S kit.
Thanks

[docnjoj]

Thanks! I appreciate the update and would like to see the video.
otherDoc

[agniusm]

Here is a vid guys for some ideas to make a drilling jig for cells, starts @ 00:44:40:

I have seen this method of connection, rough for my taste and untidy but that's just my opinion.
For a tight fit you will need 3.5mm drill bit, for looser fit 4mm should do. I will post the dimensions when i get the stuff to be exact. Warning: do not use any long conductor material as you will get shorts!!! I was trimming my tabs with long scissors and burned tabs. Anyhow, that should be in my vid on assembling the pack. Cheers

[deVries]

I thought i will do a vid on tube like a manual on "how to assemble the kit in to a pack" i think it would be more informative than paper manual.

Yes! Excellent idea! Look forward to your video.

Congratulations for doing these before your marriage! Congratulations on marriage too.

I guess this means the next batch will be sometime in June?

Guys, look forward to your battery build threads using these parts.

Btw, I think you said using copper one could pull 70amps. Does this mean 70amps per pouch/cell or ?

[agniusm]

Thanks. Its hard to say what one can pull from the pack. The formula is too complicated and too many factor to take into account and i am thinking of testing it but still have no idea on how to pull 100A at 6S? I meant the whole pack, not pulling 70A from single cell. The thing with copper is it is soft and you would easily damage threads. Thats why i'm using brass. It is around 12mm long from the tabs going through M8. If there will be interest i will do second batch in may. Cheers

[Kin]

I'm not sure about pulling 100A, but one of the ways people pull higher loads without a bigass resistor is with banks of halogen lights. The halogen lights act as resistors, but also are heat sinking themselves by putting out some of that energy as visible light and projected heat.

I don't know how precisely to go about it, though, because the resistance isn't as constant as a resistor within parameters. Alternatively, for ~$15 you can buy (6) 100 watt resistors from ebay.

[SamRam]

Sweeeeeet. I definitely look forward to this simple and genious wiring solution.
Just a quick question, do the traces connecting to the bms experience a high current, or does this power only come from the minimal amount of balancing from the bms?

I have muked around with a ping battery bms, and understand the basic operation. I am just unsure of the loads and actual wiring of my new pack. Could anyone point me in the direction of internet based learning for bms hookup?
Please and thanks

Sam

[agniusm]

I'm not sure about pulling 100A, but one of the ways people pull higher loads without a bigass resistor is with banks of halogen lights. The halogen lights act as resistors, but also are heat sinking themselves by putting out some of that energy as visible light and projected heat.

I don't know how precisely to go about it, though, because the resistance isn't as constant as a resistor within parameters. Alternatively, for ~$15 you can buy (6) 100 watt resistors from ebay.

Thanks. For 100a test i would need 44 resistors @100 wats. to complicated and expensive for single test. I can get thou 500w heat bulbs but whats going on with voltage? they are rated at 240V and i would feed 43.8V tops.

Sam, there is little current going throug balancing traces, i will give you max suported on a trace on my kit.

[agniusm]

Some good and bad news. PCB's are ready and i am going to pick them up on Monday. CNC firm contacted me to let me know that they broke lots of bits on their CNC and will take them till May to get replacements. I sourced 5 other companies and sent them request for part manufacture and quote. Hope this will be quick. My apologies for the setback. Will be informing as i get news.

Sam, BMS witing is simple, i thought you should of got wiring diagram from PING? Well, here are few examples on wiring:
http://visforvoltage.org/files/u2627/bms_wiring.jpg
http://bmsbattery.com/330-582-thickbox/lifepo4lithium-ion-smart-bms-for-513-cells-in-series.jpg
http://www.ecitypower.com/download/Collection%20of%20AE%204S-8S%20BMS%20Discharge%20and%20charge%20together%20Circuit.jpg
Sometimes so called smart BMS need positive thin wire connected to BMS for MCU to operate properly.

P.S. PCB traces would hold 3A current.

[docnjoj]

I have a question about the Signalab/Ping BMS. I have used them for years and have very little problem (except when I left the battery alone for a couple of months ) I then had to rebuild a 48 volt pack to a split 36 volt pack and it was interesting and a good learning experience. It is still in use 2 years later.

OK the question since Ping BMS allows the cells to go up to 3.9 volts as it balances, is this damaging to the cells? My 14 cells are on the way and I need to get as much info as possible to build the pack with agnisms kit. I am planning to use the Ping BMS.
Thanks in advance.
otherDoc

[agniusm]

The limits for lifepo4 chemistry are 2.0V bottom and 3.65 Top, so yes it does damage your cells in some way. Possibly shortening cell life. Most case scenario lithium batteries would like better to be discharged above 2.0V limit and charged without hitting top limit. This way you will get more cycles out of them.

I had some spare time to think about the "P" setup requested. It is an early draft, but sharing anyways. It should come out little more costly as i would need to use pure copper for outside clamps as current will flow between paralleled cells in series. End terminal blocks as well out of copper, as 2P, 4P will allow to pull tons of current.
Here is 2P6S setup:


2P6S board size is 78x160mm compared to 48x160mm in 6S configuration
End terminals would come out through protective plate and The Builder would have a choice to drill it where he needs it, the size he needs it to be and trim it
Cheers

[docnjoj]

Thanks for the quick response, agniusm. In that case I will email Cell-man and see if his bms is ok. It should be as it is the one he sells with his batteries.
otherDoc

[999zip999]

I think they are customize for Ping to 3.85-3.9v. The headways like a lower hvc. So what BMS limits for A123 in real life. ? Docnjoj let us know your choice.

[pgt400]

Thanks for the quick response, agniusm. In that case I will email Cell-man and see if his bms is ok. It should be as it is the one he sells with his batteries.
otherDoc

Checkout the mini-bms from clean power. very well made, inexpensive. I've been using one for over a year.

[docnjoj]

Thanks pgt400 I will do so.
otherDoc

Edit: I just tried Google but can't seem to find that particular company. Do you have a link?
Thanks
otherDoc

[dnmun]

cell-man sells the headway BMS with his packs i think. it puts the cells right on 3.65V because they add some resistors to the calibration of the divider bridge at final test so it is right on 3.65V. all the BMSs use 3.9V as the cell level HVC. also the headway BMS has bigger output fets than the signalab.

[agniusm]

Clean power BMS is here: http://minibms.mybigcommerce.com/, 232USD for 16S is some money. I would suggest looking at Chinese manufacturer here:http://www.foundingpower.com/en/Products/Smart_BMS/2012041639.html
I bought one for myself but have not tested it. I like included LCD with it as well as programming cable so you can setup LVC and HVC to your preference. My mate said it works good, cant vouch thou.
Look at this thread: http://endless-sphere.com/forums/viewtopic.php?f=6&t=35151&p=512272#p512272

[agniusm]

I have found a small program to calculate copper busbar ampacity. Here is the link:
https://docs.google.com/open?id=0B56NVZIdTBFObnJuUTF0SlV0eGM

[docnjoj]

Thanks guys! I guess I will go with Cellman.
otherDoc

[docnjoj]

I'm not sure that this is the correct thread for this but I just got my 14 cells from Xin. They all checked out at 3.27 to 3.28 on a fairly accurate old Knight VOM. Yippie! DHL from China was less than a week. Now for the rest of the charging and testing! I have 2 Voltphreaks chargers in // for about 4 amps current to 3.65v so it's gonna take a while.
otherDoc
edit: fixed math error

[pgt400]

you meant 3.28 and not 3.8 right?