There has been much discussion over the years about how to run a pack (regardless of size) without a BMS. There have been many cases where a faulty BMS killed an expensive pack.
I am not going to say that this is a good idea, but many do it.
I suspect you want to avoid buying an expensive balancing RC charger. They are made to run off of a 12V car socket, but....since many charge at home too...they can take a higher input voltage in order to raise the max charging amps, and to also access a greater efficiency (higher volts allow lower amps, etc). Due to these reasons, they are often built to accept any input voltage from 10V to 30V DC. The well-regarded iCharger 106B is one option to compare others too (106 = 10A of max charge, up to 6-cells capable). If you want to charge with this unit at home, you will need to add a 120V-to-12V power supply (10-18V DC output at 10A max, for the 106B).
There is another route. You can create a gang-socket. Each end of the four cells has a wire going to the Gang-socket, for eight individual sockets (actually ten sockets, see below). A plug is configured so that it cannot be accidentally plugged-in backwards. When the "run" plug is inserted, the pack is configured as a 1P / 4S pack, and will provide an average of 3.6V X 4S = 14.4V. You must add two additional large sockets for the eight sockets to be connected to the "power out" cables.
When you want to charge, pull the run-plug, and insert the charge plug. This plug looks similar, but the butt-end of the pins are connected so that the pack is now a 1S / 4P unit, and can be charged with any 4.1V charger. Most chargers provide 4.2V when the pack is fully charged. Do NOT do that. Look for a "Li-Ion" charger that has a 4.1V setting. Put a resistor between each of the four cells on the charge plug. If not...a cell that is a little high will try to rapidly charge a cell that is a little low. (due to individual cell resistances, a pack that is at 3.7V will have some cells at 3.6V and others at 3.8V, this is the whole reason why "balancing" is needed).
The gang-socket is what Tench did on his Supercharged Specialized Big Hit mid-drive. The two large pins on the right are power-out to the controller. The six large pins on the left are the series pins for the three 6S LiPo packs, to equal 18S. The many small sockets on the blue thing are for charging. Of course there are 25 holes, Three for the negative leads of the three 6S sub-packs, 18 for the positive leads on each cell, and (*scratches head, stares into space, sips beer...drools a little), and four? are unused....He used three RC chargers to tame this beast.