i want to join two lipos of 3 cell 11.1 v, 1800 mah and  1000 mah. i want to increase its mah capacity but wants 11.1 volt

tell me how to do it or its link for understanding the same

further i have searched two plugs

harness plug 2 pack in series
or harness plug for parallel connection

futher tell which plug is to use or how to use

kp

If you want 11.1, connect them in parallel

It is not a good idea to connect two LiPo's of different ratings

@kamalsahai,
I suggest you avoid connecting the two lipos.

1. If you connect the red wire of one to the black wire of the other, and the black wire of one to the red wire of the other, YOU WILL GET A BIG EXPLOSION.

2. If you connect the two red wires to each other, and the two black wires to each other, you'll get 11.1 volts, and your capacity will increase. But two other things will happen

a. As the voltage may differ between the two lipos, the higher voltage one will try to charge the lower one.
b. Suppose your motor draws 18amps. The 1800mah lipo will discharge at 10C, but the 1000mah lipo will discharge at 18C. So its voltage will drop faster. This is like using an unbalanced lipo.

So please try to avoid.

If you tell us more about why you wanted to join them, perhaps members will suggest alternative suggestions.

Regards

To increase the capacity of a battery you need a parallel connector.

however you do so only when both the batteries are of same capacity & discharge rate, also the number of charge/discharge cycles on both should be approximately the same.

else either of the batteries you use may get damaged...

Iyer Sir that's a very amazing explanation and something I have thought but never implemented. Now I know the intricacies. Gem of a knowledge, Thanks.

To increase capacity of the battery, cells to be joined in parallel (Red to Red and Black to Black) and to increase voltage it is to be joined in series (Red of one to black of other).

Lipo battery manufacturers join lipo cells in series and/or parallel to provide different voltage and capacity and the configuration is marked on the battery. For example if a battery marked with 3S1P, that meas it has total 3 same type of cells in series (S for series and P for parallel).

While joining lipo cells, they should have
1. Same capacity
2. Same discharge rate and
3. Internal resistance of each cell to be equal or nearly equal.

When the above conditions are satisfied there is no problem to join lipos in series or parallel.

So if you have more than one same type of new battery there is no problem to join them in either parallel or in series, but avoid joining used battery.