I've got an iCharger 106b+ that I really like. It's the one that all the other B6 chargers are clones of. It needs a separate power supply though, and it's not inexpensive.
This one is tried and true. It's nice because it has the charging brick built into it (literally a 12V laptop power supply in the top half of the case). It's only 50W, so if you need to charge 4S batteries or 3S larger than 5000 mAh it's not going to be able to do it at "full speed".
Quick charging summary. You always want to charge at a 1C rate or lower, you take the mAh capacity and divide by 1000 to get the charging Amperage. 5000 mAh battery = 5A charging current. The needed wattage is the charging current multiplied by the charged battery voltage. 2S is 2 cells times 4.2V = 8.4V, 3S is 12.6V, 4S is 16.8V. So for a 5000 mAh 2S Lipo battery you get 5A x 8.4V = 42W.
Or if you want to make it easy, just use this site. Sorry for all the math but sometimes it helps to know how it all comes together. Maybe that's just me, curse of being an engineer I suppose.
So: 1C charge rate, max charging current is based on your battery size. If you're only running 2 and 3S lipos around 6000 mAh size you'll be fine with a simple 6A, 50W charger like the one I linked. If you're getting into 4S, get something that's 100W or better. I started out with a B6AC that served me well for years. (I swear I didn't set out to write a huge post, it just happens.)
Oh and when you're done running for the day, set the charger to storage mode and it'll either charge or discharge your battery to the best stable voltage to keep them at, roughly 3.85V per cell.
Your gonna want a charger, and I would recommend this one
Make sure to buy all the necessary adapters and charging leads.
This is what you want It can charge up to 6s!
Just find one that plugs into the wall. Like this: https://www.amazon.com/Genuine-Professional-Battery-Balance-Discharger/dp/B0722NGPBS/ref=sr_1_14?keywords=lipo+charger&qid=1559594162&s=gateway&sr=8-14
Most chargers will charge 2-6s. This is a very popular one https://www.racedayquads.com/products/hota-d6-pro-dual-channel-325w-15a-ac-dc-battery-charger
If you want a basic one check out https://www.amazon.com/Genuine-Professional-Battery-Balance-Discharger/dp/B0722NGPBS/ref=asc_df_B0722NGPBS/?tag=hyprod-20&linkCode=df0&hvadid=312136795426&hvpos=&hvnetw=g&hvrand=13316671860231742752&hvpone=&hvptwo=&hvqmt=&hvdev=m&hvdvcmdl=&hvlocint=&hvlocphy=9012069&hvtargid=pla-569131670574&psc=1