/diy/ - Do It Yourself

I bought an old suitcase and turned it into a boombox. I'm considering buying a 5000mAh 6S LiPo battery from hobbyking, but I need a practical and easy way to charge it once it's inside the suitcase.

I've thought about buying this BMS:

http://www.batterysupports.com/22v-24v-6s-30a-6x-36v-lithium-ion-lipo-battery-bms-pcm-pcb-p-475.html

The same site also sells this charger:

http://www.batterysupports.com/liion-lipo-252v-222v-2a-6s-wall-socket-battery-charger-ac-dc-p-135.html

Isn't that charger basically just a transformer? If so, could I also use it to power the amplifier directly when I have access to a power socket?

Also, It doesn't seem to be a CC/CV charger, which to my knowledge means I should charge the battery slowly to reach full capacity. I read somewhere that 0.18 C (In this case 0.9 A) is slow enough, but how would I limit the current to that? Can I just put in a resistor with R = 25.2v / 0.9A and appropriate power rating?