my new build everything ive bought so far

4 x 8000mah 30c 6s lipo floureone
2x imaxb6 chargers
2x power supplys for imaxb6
1 motor kit 48 volt 1000 watt
2x xt90 parelle cables
2x xt90 series cables
gunna buy a bike at walmart soon

if you have any tips or things ive missed let me know

my plan is to use 2 imaxb6's to charge 2 batteries at a time a little time consuming but simple enough for me for a first lipo build
basically im doing a standard 48 volt 4 brick pack but at 16 ah

lipo build
basically im doing a standard 48 volt 4 brick pack but at 16 ah

Click to expand...

First off, 12S of Lipo does not make a "standard" 48 V pack, which has a top charge of 54.4V
12S of Lipo will have a top charge very close to 50V.
The reason I mention this is this;
The Key to a worry-free Lipo powered Ebike is a hard and fast Low Voltage Cutoff, which in the case of 12S is 42V.
You need to check and make sure the kit controller has this.

Your plan for charging leaves much to be desired.
The thing to avoid is dis-connecting("breaking")and connecting the pack, especially with Xt90 connectors, which I have found to be hard to work with.
Not only would this be laborious, it invites mistakes.
Eventually, on some late nite, when you are tired, you will make a mistake and with 8000 mAh/30C behind it, there will be a Hell of a spark.
The advantage of 12S/2P Lipo packs is there are bulk chargers that will work and you can get by without a BMS(3P requires a BMS, I.M.O.) and you need to take advantage of these two facts.
The best bulk charger for 12S is the Meanwell HLG-320-48A or HLG-320-54A;

http://www.trcelectronics.com/View/Mean-Well/HLG-320H-54A.shtml

These are not cheap, but they do not require an AC to DC power supply(They are a AC to DC PS!, but with CC and CV), are extreemly durable, are dead silent and fast charging.
You will need to install a $5 mini Volt meter(Or better, something like a Watts Up), with which the top charge Voltage is set and once the pack is plugged in, will monitor the charge process(batt. Voltage).
And unlike a balance charger, which continualy goes thru "cycling" up and down as it reads the cell voltages, this LED PS, starts charging instantly and will maintain whatever charging current you want. That's up to 6.5 A X 50 V = 315 Watts.
Expect a fully dis-charged(which you shouldn't do when it can be helped)12S pack of 16 Ah to fully charge in less than 1 1/2 hr.s, as opposed to all night using a pair of Tinker Toy 50 W chargers.

For the cell monitoring and balancing, use 4 of theses;

http://www.hobbyking.com/hobbyking/store/__71722__HobbyKing_8482_Battery_Medic_System_2S_6S_AR_Warehouse_.html?strSearch=battery%20medic

Spend the money now to work with your Lipo and your life will be much easier. And when one considers, this power supply will out-last the Ebike and no AC PS is needed, I believe this combo is the best value for safe Lipo charging over the long run.



Charging simple 12S/1P to show components.



Charging 12S/2P pack in bike.

XT90 connectors have female 4.5mm bullet connectors for both positive and negative side. This makes putting them in series real easy using male to male 4mm banana plugs, for a 12s2p pack, you only need 2 of them, but since you've already bought 2 parallel xt90's you will only need one to put the packs in series. But I understand on how you plan to do it, and that will work fine too. The only other thing I'd suggest is that you parallel the packs at cell level. For this you need 2 of these, one for each 6s paralleled packs, which you can leave in place all the time. It will insure the paralleled packs always stay in balance at the cell level.
http://www.hobbyking.com/hobbyking/store/__71981__JST_XH_Parallel_Balance_Lead_6S_250mm_2xJST_XH_AR_Warehouse_.html?strSearch=2xjst
When you charge you'll need to remove the xt90 serial adapter each time with how you plan to charge, but that's not something you're likely to forget since otherwise you'll only have one connector to plug 2 charges into. You realize it will take over 4 hours to charge your pack using the two 50A chargers. I would have probably chose a different charging setup, but what you plan on will work fine.

wesnewell said:

XT90 connectors have female 4mm bullet connectors for both positive and negative side. This makes putting them in series real easy using male to male 4mm banana plugs, for a 12s2p pack, you only need 2 of them, but since you've already bought 2 parallel xt90's you will only need one to put the packs in series. But I understand on how you plan to do it, and that will work fine too. The only other thing I'd suggest is that you parallel the packs at cell level. For this you need 2 of these, one for each 6s paralleled packs, which you can leave in place all the time. It will insure the paralleled packs always stay in balance at the cell level.
http://www.hobbyking.com/hobbyking/store/__71981__JST_XH_Parallel_Balance_Lead_6S_250mm_2xJST_XH_AR_Warehouse_.html?strSearch=2xjst
When you charge you'll need to remove the xt90 serial adapter each time with how you plan to charge, but that's not something you're likely to forget since otherwise you'll only have one connector to plug 2 charges into. You realize it will take over 4 hours to charge your pack using the two 50A chargers. I would have probably chose a different charging setup, but what you plan on will work fine.

Click to expand...

XT90 got 5mm not 4mm.

i think they are the best connectors and not so hard to work with if you use them a while

Joppo said:

XT90 got 5mm not 4mm.

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I'm not sure what size they are but 4mm banana plugs work fine in them. They appear somewhere in between 4 and 5mm to me. Maybe 4.5mm. I can't get my calipers inside them at 5mm and I can at 4.5mm. If they are in fact 5mm, these would provide a tighter fit.
http://www.hobbyking.com/hobbyking/store/__76329__4mm_Female_to_5mm_Male_Polymax_Connector_Adapter_10pcs_per_bag.html

i appreciate the feed back on the build as for the charging setup im most likley not going to be riding it everyday if i was i would look into a bigger charger so i could charge while the pack is hooked up. or aleast to where i could charge 2 batteries in par at a time. also my budget was pretty tight so imaxb6 was the logical choice for this build i might upgrade down the road. also i dont have alot of exspirence with lipo yet so breaking down my pack to charge it will help me learn to charge safely

wesnewell said:

Joppo said:

XT90 got 5mm not 4mm.

Click to expand...

I'm not sure what size they are but 4mm banana plugs work fine in them. They appear somewhere in between 4 and 5mm to me. Maybe 4.5mm. I can't get my calipers inside them at 5mm and I can at 4.5mm. If they are in fact 5mm, these would provide a tighter fit.
http://www.hobbyking.com/hobbyking/store/__76329__4mm_Female_to_5mm_Male_Polymax_Connector_Adapter_10pcs_per_bag.html

Click to expand...

your right wesnewell, they are about 4.5mm. i was out in the garrage just now and i have also used 4mm banana plug on them. always thought it was 5mm, dont know why

You thought that because that's the way most vendors advertise them. Here's one with the correct specs on them.
http://www.allerc.com/hyperion-xt90-4-5mm-female-connector-3-pcs-p-10259.html