ok... similarish qn.

iv just recently gone from 1:18th to 1:10th and iv noticed that compared to micros/minis, the bigger electronics are a real kick in the pills for your wallet. im used to forking out $20 on ebay for an ok lipo but for 10ths its anything over 100. So... i was wondering. i have in the past bought 1500mah 20c 11.1v lipos for my 18ths and been happy with there performance and price. iv been thinking of wiring up 4 of these in series to make them 6000mah and 80c for my 10th. the dimensions of 4 packs together would fit perfectly. however i hav no experience wiring lipos in series and i know that precautions should be taken. should i charge the individual packs separately and then wire them in series on each charge? or somehow rewire the ballance wires and charge it like a single pack on 4c? cheers