Charging in series

[Howie]

Hi,

I'm pretty sure I have this right, but I wanted to double check just to be sure.

I have a icharger 1010b+ that is capable of charging 10s lipo and I run 20s on my bike. I've been breaking everything down and charging each of the four 5s packs individually, but It'd be nice to do two 10s (2x5s in series) at a time.

Looking at the balance board that came with the charger, the two 5s balance ports aren't marked but the board itself has a negative and positive side, which corresponds to the cable that runs back to the charger. On my 10s (2x5s) pack, does the balance tap from the pack on the negative side, the battery with the "loose" negative cable that plugs to the controller, does that balance tap go to the side of the balance board marked negative?

I hope my question makes sense, and if not, I can take pictures. Any help is appreciated.

 

[TMaster]

Here is a pick of the balance boards. It's pretty simple. 5S in one connector, 5S in the other connector. All the negatives on one side lined up with the balance wire. Don't forget the two packs need to be wired in series to charge ports.

 

[Howie]

Ok, so does it not matter which balance plug goes into which port on the balance board? I could have swore it was important, but maybe I'm thinking of charging in parallel.

As far as making sure the polarity is correct on the plugs, the sockets on the board will only allow the plug to go in one way so that shouldn't be a big deal.

 

[Trackman417]

Ok, so does it not matter which balance plug goes into which port on the balance board? I could have swore it was important, but maybe I'm thinking of charging in parallel.

As far as making sure the polarity is correct on the plugs, the sockets on the board will only allow the plug to go in one way so that shouldn't be a big deal.

It is a big deal. If you think it isn't, you can have fun buying a new paraboard . They have to be put in order of the battery's. The first battery, goes to the first connector, second battery in series goes to the second port.

 

[Howie]

Ok, so does it not matter which balance plug goes into which port on the balance board? I could have swore it was important, but maybe I'm thinking of charging in parallel.

As far as making sure the polarity is correct on the plugs, the sockets on the board will only allow the plug to go in one way so that shouldn't be a big deal.

It is a big deal. If you think it isn't, you can have fun buying a new paraboard . They have to be put in order of the battery's. The first battery, goes to the first connector, second battery in series goes to the second port.

Haha! I don't want to hurt anything and buy replacement parts that I can avoid, hence me asking. The problem is, and this might be a given, but when viewing the board "right side up" where you can read the screening identifying the sockets on the board, is the left the first connector and the right the second? I'm not sure if I'm explaining myself clearly, but would the cable from the 10s pack thats connected to the charger match the polarity shown on the board down by the socket for the cable that runs back to the charger?

There is no marking identifying which socket on the balance board is port 1 vs port 2 for the 5s, or any of them. Sorry if I'm making this more complicated than it needs to be, but I'd rather avoid an "unplanned thermal event" if I can.

 

[TMaster]

Use a multimeter and test the continuity all the way from the connector going into the charger to the connector on the balance board. Easy Peasey.

 

[amberwolf]

wikied:
http://www.endless-sphere.com/w/index.php/Why_You_Can%27t_Connect_Your_Batteries_in_Parallel_and_Series_at_the_Same_Time

 

[Howie]

I had looked at Methods battery setup and that does look real cool. I just can't afford it right now, and it'd take some planning to get it all stuffed into the bike if I could.

I guess I was just second guessing myself and the plug arrangement was straight forward for the 10s charging. Nothing seemed to be unhappy anyhow, so thats good...

I soldered some parallel adapters for the 20s2p setup for when the batteries show. Soldering 10 gauge wire is a PITA, and now I'm second guessing those. The connections are solid, I can't bust the connection, and I think they'll be fine but my cheap meter doesn't show ANY resistance, and that's suspicious to me. I did see some guys are making parallel connectors by pinning and soldering together the 5.5mm bullets directly together. I'm going to give that a shot once some more parts arrive and I'd rather go that route since they're both mechanically connected and soldered.

I'd be happy if it stayed 65 degrees and sunny all Winter, but I find myself kinda hoping for a little snow. I have some fat CST Cyclop tires on now that are great, but I kinda want to try the Hakkapeliitta W240s.

Any thoughts on the parallel connections for the packs? If it matters, I use 5.5mm bullets for everything since thats what the batteries come with.

 

[Howie]

My other 4 batteries showed, and all cells were within .03v so I gave them a balance charge and hooked up the full 20s2p 16Ah pack. Attached is a picture of it in the bag, and I'm going to raise the seat up over the bag so I'm not putting weight back on in. Instead of my janky solder job I ordered 8 packs of Castle Creations 5.5mm bullets with the holes that I thought went through both sides but it's just one side. So after a little dremel action I slid the 3/32" copper rod through and soldered up 4 male/female/male and 4 female/male/female adapters. Mine don't look so hot right now since they're covered with electrical tape till I get some bigger shrink tubing, maybe some plastic dip, we'll see. They're rock solid though, I tried to bust them loose and I couldn't do it, so they're good to go. I don't see a lot of people using the bullet connectors, but you can see what I'm talking about here...

http://www.rcgroups.com/forums/showthread.php?t=1470953

I have a couple more questions, if anyone cares to help out.

I have 2 packs connected in parallel x 4. I have two 10s2p packs taped together just to make it easier to charge till I get the bulk charger. The 10s balance charger should see each half as just a 10s battery, it'll just take longer to "fill" the 16Ah. I have the balance leads of each subpack paralleled, and if I'm not mistaken, I can leave them in parallel and balance charge each 10s2p pack just like I would when I charge 2 packs in series. I'm 99% sure thats right, but I guess I just wanted to verify with the pros as it would suck to vaporize connectors and damage batteries. I've seen a lot of threads about lipo fires and shorted packs so I'd rather clear up that last tiny bit of doubt and get it right, than end up getting it wrong.

Last question, I read in another thread that at 36v a basic rule of thumb is 1Ah=1 mile and for 48v .75Ah=1 mile. I understand a lot of variables affect that like speed, hills and wind speed. Since the efficiency goes up from 36v to 48v, is there a further efficiency bump going to 20s? This might be a moot point, I'm going for a ride tomorrow to see what kind of distance I get, but I wondered if I'd guestimate my range based on the 16Ah or the 80% DOD which would be 12.8Ah. **I just checked the CA and for my short 1.25 mile ride to the store I used .52Ah, but I don't know if that ratio will hold up, I'll find out tomorrow.

 

[999zip999]

warp a peice of color tape on the two different plugs and color the socket on the board to make it easy.

 

[Howie]

warp a peice of color tape on the two different plugs and color the socket on the board to make it easy.

Good tip. Anything that helps idiot proof things is a good thing. The bulk charger should be here soon so I won't have to break the pack down, just plug in the battery medics, but even then that will help when it's time to balance the 10s2p module subpacks.

 

[amberwolf]

Last question, I read in another thread that at 36v a basic rule of thumb is 1Ah=1 mile and for 48v .75Ah=1 mile. I understand a lot of variables affect that like speed, hills and wind speed. Since the efficiency goes up from 36v to 48v, is there a further efficiency bump going to 20s?

It's not an efficiency boost; it's that it takes less Ah (amps over time) when the voltage is higher, but the Wh (which is how much power you use over time) is the same.

36V vs 48V is 25% more voltage, and thus the current is 25% less, for the same watts.

(sometimes it's not that simple, but that's the basic idea)