please help me understand how to connect my new battery

tmb41

10 mW
Joined
Sep 8, 2013
Messages
27
Location
Pittsburgh PA
All,

I started out with an E-bike kit with an SLA battery (36v12a) to see how often I would use the bicycle. I ended up loving it and now that the SLA battery is getting older, I'm upgrading to a LifePo4 battery. I bought one off of ebay (36v20a) with SquareTrade 3yr warranty. The problem is it doesn't come with the connections ready to go. Can you help me figure out what I need and what I need to do?

The first pic shows what I have right now. The second picture is the type of connector my old battery would connect to my controller. Thank you for your time!

photo11_zps908972ec.jpg


photo21_zps614ca6f5.jpg
 
As long as you get it hooked up in the right polarity, the connector types don't matter. I use XT60's to connect to my controller, but use 4mm bullets elsewhere. Those look like Anderson power pole connectors on you sla pack, so if you if you want to interchange the packs, use the same type on the new pack. For reference only.
http://www.gigaparts.com/Product-Lines/Power_2/MFJ-11C06.html?gclid=COftiqqhvb0CFZJj7AodmUIAbw
 
wesnewell said:
As long as you get it hooked up in the right polarity, the connector types don't matter. I use XT60's to connect to my controller, but use 4mm bullets elsewhere. Those look like Anderson power pole connectors on you sla pack, so if you if you want to interchange the packs, use the same type on the new pack. For reference only.
http://www.gigaparts.com/Product-Lines/Power_2/MFJ-11C06.html?gclid=COftiqqhvb0CFZJj7AodmUIAbw

The link you sent is definitely the connectors currently used on my controller. What I still don't understand is the two connectors they sent me. How do I wire it to the connectors on the controller and also the charger? Do I need to splice?

Thanks
 
those two black wires comin goff the BMS are for the charging lead and for the discharging lead.

you have to put anderson connectors on the red wire from the battery and the black wire from the BMS where it says P- on the BMS. that is the one that goes to the controller black wire, with black anderson connector.

the back wire that comes off the outside of the charging plug is the one that goes to the C- spot on the BMS. if you cannot find them post up a picture of the traces of the BMS so we can tell you.

the red wire on the charger plug goes to the positive terminal of the battery which the red wire coming out of the battery is connected to your controller red wire with a red anderson connector.

you can work out where you have to mount everything on the bike and then run wires from the BMS to the charging port.
 
dnmun said:
those two black wires comin goff the BMS are for the charging lead and for the discharging lead.

you have to put anderson connectors on the red wire from the battery and the black wire from the BMS where it says P- on the BMS. that is the one that goes to the controller black wire, with black anderson connector.

the back wire that comes off the outside of the charging plug is the one that goes to the C- spot on the BMS. if you cannot find them post up a picture of the traces of the BMS so we can tell you.

the red wire on the charger plug goes to the positive terminal of the battery which the red wire coming out of the battery is connected to your controller red wire with a red anderson connector.

you can work out where you have to mount everything on the bike and then run wires from the BMS to the charging port.

Thank you! This helped a lot. I know now which wires should go where. I'm still confused on the red wire, however. If the red wire needs to connect to the charging plug and also the controller connector, what's the best way to splice into it?

As far as mounting goes, I'm putting the battery and controller in a trunk on a rear tire rack so wire length shouldn't be an issue. The only wire coming out of the trunk will be the throttle which is plenty long

Thanks again
 
Solder the red wire directly to the output connector.Then solder a second thinner (5amp or whatever your charge current is) wire to the same terminal and loop it across to the charge socket. Whatever you do, check and doule check the polarity of your battery and charger connectors before you connect to the charger and controller.
 
There are 4 red wires connected together. Two are from the controller, one is the battery, and the last is to the charger.


The skinny black wire from bms is connected to the skinny black wire on the charger

The thick black wire from bms is connected to black wire on controller
 
If you've got the controller hooked up while trying to make the connection in the photo, the caps in the controller cause the spark. You can add a precharge resistor to the circuit to avoid that spark. or disconnect the charger and controller first. Then it will spark where you plug into the controller unles you use a precharge circuit like this.
 
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