How do you charge your A123 cells...

Ok.. so i've just about had it with the dewalt bms; it's probably the worst charger to do balancing i've ever seen 6 of my cells showing 3.7; 3 showing 2.53; and one at 3.4v;

I want to start on building my 100v pack for my bike; but i still need to find a better method to balance and have a quick charge time...

a few things i'm looking for are

- I've seen this somewhere on the forums before; but its a display that shows individual cell voltages; where can i find this anyone?

- A a123 balancer & charger combo thats works really well.

-i'm still try to decide on a method to do my packs; or split them up; but i figure if i can find a charger that will charge say 30 cells in series at a time?; i don't know if that may be very pricey; the most i've seen is a 12cell or 13 cell charger ..

- a method to parallel & series the cells together.. i think i'm looking for a battery tab welder & some nickel strips; i want a method in which in the event of a bad cell i won't have to pull a mission to fix it .. but i believe the battery tabs to be the only way ..

P.s. thats my bike in process of being built; i'd like to put the packs near the front of the the bike near the suspension on the sides of the frame...


Please late me know your thoughts & suggestions

-steve

I finally gave up trying to keep my A123 packs perfectly balanced after each charge. I rarely discharge them more than ~80% so it's not been an issue.

For day to day "bulk" charging I use three Mastech 30V/20A CC-CV (HY3020E) power supplies to charge my packs. Each charging cable has a big Schotty diode with a heatsink to prevent the packs from ever discharging back into the PS.

Every week or two after charging I balance my packs using a Hyperion LBA-10 (the newer one with A123 support):
http://www.b-p-p.com/proddetail.php?prod=2_LBA10

So far I'm very happy with the speed and simplicity of this setup.

Beagle123 said:

Another option is to charge the cells individually at 3.7v.

Click to expand...

I guess to charge more than one cell at 3.7 volts, you would have to hook the cells up in a parallel configuration?

Edit answered my own dumb series question

Steveo

Charge them with a Bantam
Forget about a BMS. You CAN balance without one.
The key to making this happen it to wire taps on when you build the cell and the let the charger take care of balancing rotuine in the charge cycle.

You will be able to monitor the cell voltages as it charges.

This is a SIMPLE way to accomplish what you want.

Check it out at http://www.rcaccessory.com/index.asp?PageAction=VIEWCATS&Category=11

I will charge like that! :

Beagle123

The bantam 902 WILL handle 1-12cells A123batts

http://www.rcaccessory.com/index.asp?PageAction=VIEWPROD&ProdID=34

So if you are using 2packs of 10cells then it will work.
Just plug in your two 10 cell packs in parallel and your charging 20 cells.

Beagle123 said:

Hi Doc:

I'm not sure that will work. There could be a problem because the batteries are all connected together so the negative lead of one battery is connected to the positive lead of the next. That means that the the negative and positive leads of the power supply could be connected together too (short).

Unless those dc to dc converters somehow isolate from each other, I think it could cause a short.

Edit: I noticed that you said that they were isolated. If that's true, I think you may have an excellent charging method. Please keep us posted.

Click to expand...

yess they are isolated (in to out), (in to case) (out to case) 1500Vdc

I really think that will be a piece of cake to cahrge and cells between 3 and 5.5Vdc at up to 30A

Also, I already have my RC 12s charger +12s balancer. The Megapower. that work great! I use it to measure each of my new dewalt pack and also my konion cells from Makita. the graph fonction is very great and also the Internal resistor + capacity measurement are great too.

it do the same as the CBA-10 battery tester, but it charge too!

Doc

DoctorBass
Any web link to the RC 12cell "mega power charger"?

Are you refering to the Hyperion 12i?

Would like to check it out.

Microbatman said:

DoctorBass
Any web link to the RC 12cell "mega power charger"?

No it is not the hyperion 902. it's the MegaPower 960-SR

The hyperion is great but it have less features than the megapower.

Are you refering to the Hyperion 12i?

Would like to check it out.

Click to expand...

I bought the complete kit 3 month ago..

i'm very satisfied with it!

199.99$ for complete kit balancer + charger/tester for 12s
http://hobbycity.com/UNITEDHOBBIES/store/uh_viewItem.asp?idProduct=6301


at the end of this page:
http://endless-sphere.com/forums/viewtopic.php?t=2272&highlight=960sr

a review at RCgroup forum:
http://www.rcgroups.com/forums/showthread.php?t=737623&highlight=megapower

Doc

Microbatman

I like your suggestion about using the bantam balancers to charge my setup;
if i went this route .. i think i would want to setup as follows

2 x 12 cell packs or 44.4v 4.8ah each
1 x 6 cell pack of 22.2v 4.8ah

i want to charge all my cells at the same time & and easy method to connect them.

i believe i'd need 5 balancers in total.. how do i use these things; do i need a special psu?

Doctorbass

i'm really liking that megapower charger .. it has all the features i want; thing is i want to charge all my cells at the same time .. gahhh why is it hard to find a a123 charger that will charge many cells .. like 30 in series?

-steveo

Doctorbass said:

I will charge like that! :

Click to expand...

Doc: I really like that charging scheme of yours with the DC converters. Those things are so light and compact you could have them onboard as long as they're kept cool. I've got a few dumb questions I wonder if you or anyone else can help me with.

I've found some similar DC converters going cheap on ebay, but they're 300V input, 5V output at 10A (with -50% +10% output voltage adjustment).
Would it be OK to run these off a bridge rectifier from a 240V AC supply? The rectifier I was looking at is rated at 50A/1000V. Would I need to add a smoothing capacitor across the rectifier output, and if so what value should the capacitor be?

There just isn't anything out there that is "off-the-shelf" for charging and balancing big pack configurations. One of the best RC-type solutions Ive seen for doing up to 12s configurations is the Hyperion EOS0610i-NET:



Each of these are full 250W chargers, capable of charging a 6s pack at a full 10A. It has a LBA10A auto-balancer built-in, whcih works a lot better than most of the other RC shunt-type balancers, like the TP-210V, because it uses a discharge current of 300 mA, which is double.

You can connect two of these in series, to do up to a 12s pack, which means it is really a 500W charger/balancer setup, capable of doing a 12s pack at a full 10A charge rate. Almost every other RC charger/balancer setups I've seen that are capable of doing 12s setups, including the Bantam e-Station and the MegaPower unit, have power ratings of 180-200W, which means that the most current they can deliver for 12s is 4-5A. You'll notice in the specs that they say that they can deliver "up to 10A", but that is only at lower cell counts. To do 12s at 10A, you need 500W, or close to it.

The only other charger I've seen that will charge and balance a 6s pack at a full 10A rate is the BalanceProHD unit from FMADirect. You can'tdaisy-chain two of these together to do 12s together, though, and although there is a PC interface, there is no display on the unit itself. Also, these appear to be out-of-production now, as I can't find them on FMA's site anymore. The EOS0610i-NET has a display, a PC interface for data logging and firmware updates and lots of other features, like cell imbalnce readouts during charging/balancing and calculated cell internal resistance, just like the MegaPower unit. You can check out the manual here

I've been so impressed with the Hyperion units that I went the through the process to get signed up as a dealer for these, for my RC site (http://www.tppacks.com). I'll be adding the EOS06010, along with the LBA-10A 6-cell balancer (shown below...) to the site by early next week.



Once I get these up on my site I'll have to sell these at the standard list price of $169.95 for the combo EOS0610i-NET charger-balancer, and $41.95 for the LBA-10A balancer, but if anyone here is interested in either of these, I can offer a pretty good discount before they "officially go on sale on my site. I'm going to be placing my initial order with them tomorrow, so PM if you are interested.

-- Gary

Malcolm said:

Doctorbass said:

I will charge like that! :

Click to expand...

Doc: I really like that charging scheme of yours with the DC converters. Those things are so light and compact you could have them onboard as long as they're kept cool. I've got a few dumb questions I wonder if you or anyone else can help me with.

I've found some similar DC converters going cheap on ebay, but they're 300V input, 5V output at 10A (with -50% +10% output voltage adjustment).
Would it be OK to run these off a bridge rectifier from a 240V AC supply? The rectifier I was looking at is rated at 50A/1000V. Would I need to add a smoothing capacitor across the rectifier output, and if so what value should the capacitor be?

Click to expand...

The 300V input (i have sen it on ebay) can't be used with 240Vac. the reason is that when rectifying AC voltage, it increase by 1.41 factor.

So 240V become: 338V and is higher than the 300V. Plus, you would need a safety margin of around 500V.

About that for the same price, i suggest you to buy some AC-DC power supply of 3.3V or 5V at 8A that are around 10-12$(I've posted some link on this forum about that) Those have already the 120V input.

The reason why i tokle these DC DC is that they cover from 3V to 5.5V that is fine for any 4.2V or 3.7V charging. But if you dont have to charge both voltages, and just need one, you could choose the 5V to charge 4.2V with the adjust trim or choose the 3.3V by boosting it to 3.63V with the adjust trim.

Or you can wait for some new DC-Dc batch that will come on ebay with best input voltages.

Doc

Thanks Doc, I'd forgotten about the root 2 multiplication. The input range on those converters is 200-400V, so 338V would still be within spec, although I'm not sure I'd be happy with that high a voltage.

Why would I need a safety margin of 500V – is that for voltage spikes?

Yes, those DC supplies you found are really good value, but I was hoping to find something lighter and more compact.

I'll keep on looking

The Hyperion chargers are very nice products, but this model is only capable of 10A. Also, hooking up two batteries using two LBA-10's in series, and timing everything just right, can be a bit tricky - not something I would like to do every day after work.

With CC-CV power supplies like the Mastech I mentioned, I can charge my packs at a full 20 amps until they switch over to CV mode. With three power supplies charging three separate packs at ~20V each, I can charge at an effective 60 amps, ~1200 watts. All I do is plug in three cables and go. It takes around 40-45 minutes to fully charge a 18S5P A123 battery (organized as three individual 6S5P packs).

Another cheaper option for "bulk charging" would be to create a cable or circuit that parallels your packs for charging purposes. In my situation, that would make 6S15P that is then charged at 20A with a single power supply.

Malcolm said:

Thanks Doc, I'd forgotten about the root 2 multiplication. The input range on those converters is 200-400V, so 338V would still be within spec, although I'm not sure I'd be happy with that high a voltage.

Why would I need a safety margin of 500V – is that for voltage spikes?

Yes, those DC supplies you found are really good value, but I was hoping to find something lighter and more compact.

I'll keep on looking

Click to expand...

Yes, thay's for the spyke.. is yo have a big air conditionner on the same circuit breaker, when the conpressor start, the voltage spike can easyly fri the dc-dc.. maybe at 400V that could be ok, but try to put some MOV to drop these spike.

Doc

Steveo

I will show you how do what you want and make it simple and easy to understand.

I have plans on making a pack similar to what you are doing. So we are both in the same situation. Just so you know I have experence with Lipo batteries due to my interest in electric RC planes. I have tested and posted data in The RC Groups battery graph sticky forum and have been on RC groups for few years. No I do not know everything and sometimes I make mistakes.

Here is what I would buy to parallel them
http://www3.towerhobbies.com/cgi-bin/wti0001p?&I=LXHHW6&P=7

Here is what I would get to connect TWO 6 cells packs to make One 12cell
http://www.rcaccessory.com/index.asp?PageAction=VIEWPROD&ProdID=251
After the TWO are connected you plug them into the parallel board

Here is what I would get to put balance taps on each 6 cell pack
http://www.rcaccessory.com/index.asp?PageAction=VIEWPROD&ProdID=136

Here is the balancer
http://www.rcaccessory.com/index.asp?PageAction=VIEWPROD&ProdID=191

Here is the charger
http://www.rcaccessory.com/index.asp?PageAction=VIEWPROD&ProdID=311

You only need 1 Balancer. All ya gotta due is hook it up to each 6 cell pack after its charged and it will bleed off the excess volts to bring the pack in balance. Which leads us to another topic. Balancing is way over rated. On theses cells you only need to see if one is way off So put on taps and balance maybe once in 5 charges.


If you have an big wallet go for this charger that you can chage them all at onece then Get a MAstech 5020
Just hook this baby up on the parallel board above and your charging all your packs at once.


http://www.amazon.com/Mastech-Variable-Regulated-Power-Supply/dp/B000E14BNM

To see how to use it type in MASTECH on youtube.

Hope this helps. I will add to the details of this later but this is a good overview to start.

Also got any more pics of your bike. Looks Great!!!
The posted picture is a little dark. Would love to see some more in better light.

Microbatman said:

Steveo

I will show you how do what you want and make it simple and easy to understand.

I have plans on making a pack similar to what you are doing. So we are both in the same situation. Just so you know I have experence with Lipo batteries due to my interest in electric RC planes. I have tested and posted data in The RC Groups battery graph sticky forum and have been on RC groups for few years. No I do not know everything and sometimes I make mistakes.

Here is what I would buy to parallel them
http://www3.towerhobbies.com/cgi-bin/wti0001p?&I=LXHHW6&P=7

Here is what I would get to connect TWO 6 cells packs to make One 12cell
http://www.rcaccessory.com/index.asp?PageAction=VIEWPROD&ProdID=251
After the TWO are connected you plug them into the parallel board

Here is what I would get to put balance taps on each 6 cell pack
http://www.rcaccessory.com/index.asp?PageAction=VIEWPROD&ProdID=136

Here is the balancer
http://www.rcaccessory.com/index.asp?PageAction=VIEWPROD&ProdID=191

Here is the charger
http://www.rcaccessory.com/index.asp?PageAction=VIEWPROD&ProdID=311

You only need 1 Balancer. All ya gotta due is hook it up to each 6 cell pack after its charged and it will bleed off the excess volts to bring the pack in balance. Which leads us to another topic. Balancing is way over rated. On theses cells you only need to see if one is way off So put on taps and balance maybe once in 5 charges.


If you have an big wallet go for this charger that you can chage them all at onece then Get a MAstech 5020
Just hook this baby up on the parallel board above and your charging all your packs at once.


http://www.amazon.com/Mastech-Variable-Regulated-Power-Supply/dp/B000E14BNM

To see how to use it type in MASTECH on youtube.

Hope this helps. I will add to the details of this later but this is a good overview to start.

Also got any more pics of your bike. Looks Great!!!
The posted picture is a little dark. Would love to see some more in better light.

Click to expand...

First of pictures of the bike i'll be using



Shitty charger i'm useing atm

Blown BMS?

5304 motor, in process of replacing blown hall sensor; upgraded wires from 14awg to 12awg


I wouldn't mind getting this charger; but how would i be setting up the packs? i wana get then behind the front suspention; would i be building packs of 6 series 12 series or 14 is max for that charger?

could you do a sketch? just so i have an idea of how exactly i show do the packs for 100v; i understand how to do balance leads so i'm ok with that & using the balancer .. thanks
Steveo..

p.s. What are you using in your project? whats your build

The Mastech supply is good to 50V. With a123 cells, the optimum max charging voltage is 3.65-3.7V per cell, so the most it will do is 13 cells in series. I think the easiest way to do a 99V setup is to use 30 cells in series, which conveniently works out to three 10-cell blocks. One way you could do this is to have a main harness on the bike that hooks parallel blocks of 10 cells in series on the bike, and then a separate charging harness that hooks all the blocks in parallel. Here's a simple diagram:



Each of the battery symbols represent a 10-cell block. I don't know what sort of capacity you are going for, but this illustrates a 4p (9.2Ah) configuration. If you have them connected in parallel for charging, as shown, you would have a 10s12p charging configuration, or 33V/27.6Ah. With a Mastech 5020, it would take about two hours to fully charge this setup.

-- Gary

GGoodrum said:

The Mastech supply is good to 50V. With a123 cells, the optimum max charging voltage is 3.65-3.7V per cell, so the most it will do is 13 cells in series. I think the easiest way to do a 99V setup is to use 30 cells in series, which conveniently works out to three 10-cell blocks. One way you could do this is to have a main harness on the bike that hooks parallel blocks of 10 cells in series on the bike, and then a separate charging harness that hooks all the blocks in parallel. Here's a simple diagram:

Each of the battery symbols represent a 10-cell block. I don't know what sort of capacity you are going for, but this illustrates a 4p (9.2Ah) configuration. If you have them connected in parallel for charging, as shown, you would have a 10s12p charging configuration, or 33V/27.6Ah. With a Mastech 5020, it would take about two hours to fully charge this setup.

-- Gary

Click to expand...

Hi Gary

I saw your videos on the general discusion boad, i think your bikes are awsome .. that video with the dog chasing the bike is halarious .. ;

just wanted to ask you; since your dealing with 3 bikes;

are you using the Mastech 5020 to charge your bikes?;
how about your method for charging your packs? are you doing just as you advised me above?;
What are you using for balancing these packs?

-Thanks in advance
-Steveo

steveo said:

Hi Gary

I saw your videos on the general discusion boad, i think your bikes are awsome .. that video with the dog chasing the bike is halarious .. ;

just wanted to ask you; since your dealing with 3 bikes;

are you using the Mastech 5020 to charge your bikes?;
how about your method for charging your packs? are you doing just as you advised me above?;
What are you using for balancing these packs?

-Thanks in advance
-Steveo

Click to expand...

No, I don't have a Mastech 5020. Right now I have three configurations on each of my three bikes, 16s5p, 20s4p and 24s6p. For the 16s5p setup I use a Zivan NG1, tweaked to have a CC/CV cutoff of 59V. It will charge at a rate of 18A until the pack gets to about the 80% level, and then it drops down to about 6A. When the CV mode kicks in, the current tapers off to about .3A, and then it shuts off. From what I understand, these can be reprogrammed to be used with any pack from 24V up to about 80V, This is a very nice unit, and very lightweight (5-1/2 pounds...), but not cheap. I think I paid $450 for mine, from Thunderstuck-EV.

With the 20s4p and 24s6p setups, I use a bunch of 2A individual CC/CV chargers, in order to independently charge each cell, which eliminates the need for an external balancer. Here's what that setup looks like:



The only problem is that it can take quite a while to charge a big pack at a 2A rate, so I did an offshoot of the LVC circuit design to control a big 17A constant current supply in a way that during the initial constant current mode of the charging cycle, I get an extra 17A, for a total of 19A. Once any one of the cells reach 3.7V, the bulk charger is cutoff, and the individual cell chargers continue on, to do the constant voltage mode, where the current tapers off to about 200mA., which allows each cell to get a full charge. Here's what this circuit looks like:



I don't have any pics of the completed setup, but I'll try and remember to take some. Here's what the board layout ended up looking like:



The MasTech unit is nice, as it has user adjustable CC and CV settings (0-20A, 0-50V), but I just wish they had a version with a higher voltage limit.

-- Gary

GGoodrum said:

steveo said:

Hi Gary

I saw your videos on the general discusion boad, i think your bikes are awsome .. that video with the dog chasing the bike is halarious .. ;

just wanted to ask you; since your dealing with 3 bikes;

are you using the Mastech 5020 to charge your bikes?;
how about your method for charging your packs? are you doing just as you advised me above?;
What are you using for balancing these packs?

-Thanks in advance
-Steveo

Click to expand...

No, I don't have a Mastech 5020. Right now I have three configurations on each of my three bikes, 16s5p, 20s4p and 24s6p. For the 16s5p setup I use a Zivan NG1, tweaked to have a CC/CV cutoff of 59V. It will charge at a rate of 18A until the pack gets to about the 80% level, and then it drops down to about 6A. When the CV mode kicks in, the current tapers off to about .3A, and then it shuts off. From what I understand, these can be reprogrammed to be used with any pack from 24V up to about 80V, This is a very nice unit, and very lightweight (5-1/2 pounds...), but not cheap. I think I paid $450 for mine, from Thunderstuck-EV.

With the 20s4p and 24s6p setups, I use a bunch of 2A individual CC/CV chargers, in order to independently charge each cell, which eliminates the need for an external balancer. Here's what that setup looks like:

The only problem is that it can take quite a while to charge a big pack at a 2A rate, so I did an offshoot of the LVC circuit design to control a big 17A constant current supply in a way that during the initial constant current mode of the charging cycle, I get an extra 17A, for a total of 19A. Once any one of the cells reach 3.7V, the bulk charger is cutoff, and the individual cell chargers continue on, to do the constant voltage mode, where the current tapers off to about 200mA., which allows each cell to get a full charge. Here's what this circuit looks like:

I don't have any pics of the completed setup, but I'll try and remember to take some. Here's what the board layout ended up looking like:

The MasTech unit is nice, as it has user adjustable CC and CV settings (0-20A, 0-50V), but I just wish they had a version with a higher voltage limit.

-- Gary

Click to expand...

That board layout.. did you design it yourself? did you purchase it somewhere; i don't think the single cell charging method isn't so bad.. how many cells could you charge at once on that charger 10 in series but how many in parallel with the bost & without.. or do you charge each 36v pack seperatly?

thanks
Steve