As shown in the connector types article, there are all sorts of flavors and sizes of RC LiPo battery connectors out there and those photos only shows a small smattering. So which one to use can be a complicated decision when you are first starting out if you don't know much about them yet. I hope this page helps you with that :-)

The purpose of all these RC LiPo Battery connectors is simple. They offer a convenient & easy way to connect our RC LiPo battery packs into our model's ESC/Power system to complete the electrical circuit, allowing the current to flow from the Battery to the ESC and/or other electronic systems/components.

lipo esc

Most RC LiPo connectors are "polarity protected", meaning it's very hard if not impossible to plug them in backwards which goes a long way to save expensive electronics from letting out the magic smoke.

The connection must be reliable, solid, and able to pass enough current to meet the maximum current demands of the model. If the RC LiPo battery connector can't pass enough current, it can overheat and/or introduce a voltage drop.

Overheating only occurs if the over current condition lasts for a sustained period of time; so short over-current bursts, even double of what the connector is rated for, are not going to cause a hot & melted connector. A voltage drop on the other hand which could occur in such an instance, can also cause bad things to happen such as restarts to microprocessor controlled electronics (modern day ESC's, Receivers, and flybarless systems) or voltage spikes/ripple. 

This is pretty much the first thing you have to know/understand in order to choose an adequate connector for your RC powering application, the amount of current it can pull. Your motor/ESC combination or RC model should indicate maximum current ratings and that is usually a good place to start.

If for example your motor & ESC have a maximum sustained current rating of 50 Amps, then you should be looking at LiPo connectors that have a sustained/continuous 50 Amp rating or better. There are of course "real world" exceptions to this which I will talk about later in this article; but to keep things simple, this is how you first consider what size/current rating connector to use.

amp rating of connectors

I say size, since the size of the connector goes hand in hand with how much current it can pass. The larger the connector, you guessed it, the more current it can safely pass through the pins. The reason being, the more surface contact area the pins have, the more electrons they can move; exactly the same as the larger the wire, the more electrons it can move.

But this the theoretical max amp ratings are to be used as a guide only when choosing one connector over another. As we have already seen, there are variables that will affect your actual maximum current needs.

As just one personal example, I'm not a power hungry electric 3D smacker. I learned to fly these egg beaters on nitro power and managing your rotor energy was and is an essential part of flying. In short, I rarely even get to 1/2 of what my electric helicopters can pull in terms of maximum power. That is why I can safely fly a 700 size electric heli with a 60 Amp rated connector and never have a problem. Rarely will I see more than a few short bursts even close to 100 amps on my 700's; most of the time, they are sipping about 40 to 50 amps max. 

On the flip side, a high rated connector could be faulty, have a poor solder job, or coming to the end of it's useful life and not able to pass even 1/4 of the current it's rated for (my ESC 5 experience above is just one such occurrence).

So how to decide what your real current needs are?

Data logging ESC's that show current draw, external data logging power meters, and current sensing telemetry sensors are all wonderful tools to help you determine your "ACTUAL" powering needs based on hard facts. 

I'm very much partial to data logging ESC's as they give you the "big electrical picture" as to what is going on; not just current, but voltage drop, and ripple which are all helpful measurements for sorting out or determining RC LiPo battery connector issues. 

As was already touched on, a less technical way, but certainly workable, is feeling your RC LiPo battery connector for warmth right after a hard flight or drive. No RC LiPo battery connector should be getting even the slightest bit warm during use. If it is, there is a voltage drop occurring across the pins. This method won't detect short term over current bursts, but it's better than checking nothing at all. 

At the end of the day, get the right RC LiPo battery connector for your needs. The best connector current rating is the one that handles your specific power requirements with some wiggle room to spare as the connector ages and the resistance increases a bit.