I am using 3 cameras to film an event coming up and I was wondering what would be the best way to record audio.

The event is a type of wake for a gentleman who passed a few months back. All his friends and family will be in attendance and will be going to a podium and telling stories and re-living memories.

In regards to audio, I currently have a Tascam DR 100mkii that I planned on putting on the podium but I don't think it will last the entire two hours. I also have a H1 that I could use and know it will last the entire time, but I'm not sure the best course of action. I do weddings but I don't do a lot of this type of event videography.

Anyone have any suggestions?

Can you power the Tascam from a USB cell phone power bank? Have you ever tried the Blue Energizer Lithium batteries? They're pretty incredible. I bet you could get a 2 hour run time from a set. Maybe theres an AC outlet under the podium/front of the room?

Aside from that, are you able to use any wireless lavs? I often put a lav on the podium and anywhere else I might need audio. Just some ideas.

Are you using the built-in microphones? According to the User's Manual, any of the available batteries will last plenty of time.
Depending on your Sample Rate and audio output, you will need a slightly larger memory card

I like using a Zoom H1 when micing a podium, typically with the level set at about 50.

Multiple audio sources are your friend. Lav mic taped to the podium mic is a good start, and then a small recorder like the H1 taped to the podium. I can only imaging if you rely on 1 source for a 2 hour recording and it crackles, hisses or fails entirely. If you can tap into house sound and record that to an external recorder, that would be even better. Plan A, Plan B, Plan C....you can never have enough.

Stick a lav mic on a speaker. The sound guy who has promised to provide you a clean feed of the audio board will gladly watch you go down in flames and shrug his shoulders because the speakers still work even though your aux feed mysteriously disappeared. But if something causes the speakers to stop working.. full-stop, someone will find a way to fix it, or the event will stop until it's fixed.

If you have the time before the day then run your Tascam in the configuration you plan to use and test how long it lasts.