First LiPo pack... balance vs bulk charger

[dmcp]

I was hoping you guys could chime in on if I should go bulk charge or balance, maybe let me know if I'm completely wrong on something, it's my first pack.

quick backstory, I ride a gio pb710, with 48v12ah old saggy sla batteries. I'm definitely on board with lithium.

Looking now at getting 4 6s zippy 5000mah packs to make a 12s 44.4v/50.4v 10Ah pack.
these... http://www.hobbyking.com/hobbyking/store/__8582__ZIPPY_Flightmax_5000mAh_6S1P_20C.html

Here is where I'm at with a bulk charging set up;
first I'd need to wire in this BMS http://www.batterysupports.com/44v-48v-504v-12s-30a-12x-36v-lithium-ion-lipolymer-battery-bms-p-268.html
then use this charger http://www.batterysupports.com/432v-44v-504v-4a-lithium-ion-lipo-battery-charger-12s-12x-36v-p-167.html

or a balance charger and parallel charging board like this http://hobbyking.com/hobbyking/store/__53601__HobbyKing_8482_X200_AC_DC_Touch_Screen_Smart_Battery_Charger_10A_6S_US_Plug_.html
http://www.hobbyking.com/hobbyking/store/__14856__Hobbyking_Parallel_charging_Board_for_6_packs_2_6S_XT_60_.html


The way I see it both have pros and cons, bulk charging is easier, the bms pack would probably end up being built to stay permanently together, clean and neat.

balance charging would mean breaking the pack down every time, but I feel parallel charging at less than 1/2C is very good for the batteries, but then would I need a BMS or something anyways for riding (low voltage cutoff) or do I need to monitor voltage on the road with an accurate digital display meter?

 

[anon0973923]

Neither of those solutions are considered bulk charging. The first scenario has the BMS connected permanently to the bike, the other has a BMS that resides in the RC charger.

 

[DAND214]

Not related to the thread, stay away from the Zippy. Turnigy are cheaper and better. you could almost get the Multistar 6s 16ah packs for that money. https://www.hobbyking.com/hobbyking/store/uh_viewitem.asp?idproduct=66487.
Don't know where you are located but that link is in the USA.

As to bulk charging, yes you can but you better test the packs before trusting bulk charging anything. First you need a balancing charger that also discharges at a high rate or a load bank and a way to monitor that load and voltages along with time. All can be done with a watt meter, volt meter and a clock but that takes a lot of time and no interruptions.
Even with a BMS you should test the LiPo packs before you wire them up.
You might want to look here http://lunacycle.com/48v-samsung-18650-battery-pack-10ah/ A few dollars more but cheaper in the end.

Dan

 

[dnmun]

12S is not considered 48V either. it is 13S lipo that is considered 48V.

but if you decide to do this with this BMS and bulk charger you need to find a bulk charger that can be adjusted to the 50.4V DC final voltage.

i recommend removing the shrink wrap and putting the pack into compression with hardboard end plates to keep the pouches flat and in compression so they last longer. remove the JST plugs and the B+ lead of the lower pack and the B- lead of the upper pack and solder them together so it is one 12S pack and then solder the sense wires to the pack where the JST plug wires were removed.

maybe find a better BMS too.

 

[motomech]

I just went over this the other day;

http://endless-sphere.com/forums/viewtopic.php?f=14&t=71381&p=1077581#p1077581

 

[dmcp]

Thunder 1220 it is. Thanks, hope its in stock when I'm buying.