First off I'm not entirely new to soldering however I'm definitely no pro.

My issue is, I bought a Hobbywing XeRun 150a used and the battery leads are not long enough for me. I snipped the wires and removed my battery connector. I can't get the battery post hot enough to desolder the wire. I feel like the heat is just getting sacked though the heat sink.

I just got for xmas a Hakko FX-888D. I had it set up to 850 degrees. Still nothing. I can't post I video if that will help but for now here's a picture of what I see.

Did you tin the tip of the iron?

If that's just placing clean solder on the tip then yes.

Post a pic of the tip you are using, a large wide tip to transfer more heat works best.

This is the only tip I have at the moment. Upon closer look it doesn't look like the solder will even stick to the iron tip either making it difficult to tin...

Here is a quick video. Maybe it's my technique? I know the solder was heavy in this one.
https://www.youtube.com/watch?v=R2Qp...e_gdata_player

it looks like your tip oxidized, you will need to get a tip cleaner, or maybe you might be able to polish it off.

try clipping down the wire really short, so less heat gets absorbed and dissipated in the wire.

i got that same iron for christmas as well!

Can I use a wire brush to clean it?

A bigger tip will be better. Also put some flux on the wire, it will transfer heat much faster.

That is a very dirty and oxidized tip. No, a wire brush will only make it worse.

Get some tip cleaner/tinning from Radio Shack and use it every time you put the iron away. Didn't the 888 come with a cleaner (looks like a brillo pad made of brass)? Use it.

No, that will only worsen the tip.

The 888 comes with a tip cleaner, don't you use it? Looks like http://gokimco.com/brass-coil-insert.htmlis

Go to Radio Shack and get a tin of tip cleaner.

I was able to clean it with the sponge and copper mesh. Got it done. Apparently I allowed it to oxidize. Maybe I need to start from square one and learn to use it properly.

That picture was after the first time I used it to solder something together. I've never had a solder station like this and never had an issue with my cheapo iron.

Which is why you are supposed to clean and tin the tip every time you use it and while you are using it.

I have a ten year old Hakko 936 with the original tip and it still works like new and is a shiny as new.