E20 holding temps long cooks

I did my first overnight cook on Thursday. I did two briskets, one just short of 5lb and one just over 5.5lb.

The end result tasted great however the cook didn't go to plan and I think the meat would have been better if it hadn't taken 17 hours to hit 189f which is when I took it off because I was worried about it drying out.

I started the cook at 11pm, this was when the meat went on. The cooker was sitting solid at 235f at 1am when I went to bed.

I got up at four and it was sat at 225. Went back to bed and when I returned at 7am the temp had fallen to 190f so I know it held for less than eight hours. I took the top sections off and checked the fire there was a lot of unburned briquettes. When I started up I went with a basket of unlit arranged with a hole in the middle. I poured a chimney of
Lit in the centre with a few scattered over the rest. I thought with the minion method the fire should spread but it didn't seem to spread enough. In the 3 hours where the temp had dropped the temp of the meat didn't rise, in fact by the time I got a fresh chimney going the meat temp had dropped a couple of degrees.

I think this three hour period really slowed my cook down. I was wondering how long you guys can keep the e20 at temp. I had 5 kilos of weber briquettes in there and if the rest had taken I reckon it would have gone a good few more hours before dropping. There was rain overnight and a bit of wind but the biggest effect must have been the charcoal that didn't light. So I reckon either I didn't set up the best way or I didn't have enough burning mass at the start. Do others leave a gap in the centre when they start minion? How far do you spread the lit coals over the top?

Or should I expect to refuel after 7 hours? The impression I've got is that others can get 12 hours on a single load.

Any opinions would be most welcome.

well, I have used several types, and with any briquets, I am buring fast - not hot, but fast. Still trying to find the right combo.

First burn I used only lump, and the "shake" i think clogged the air circulation, and it burned really cold.

I get about 5-6 hours right now before refueling. This with a very full basket to start with.I just cant see how people can maintain 225 for over 8 hours....

My water pan though will go dry in about 4-5 hours, so that is my limiting factor.

The Weber briquettes are very dense, several people have had problems with them, I would suggest you try another brand.

I did wonder about the Weber briquettes, I have been experimenting with different brands, I had similar issues with the minion method with penbeads too.

I did pulled pork last week using Supagrill coconut briquettes and had a similar issue of losing temp after 6-8 hours, finding unburned fuel in the pan, adding another chimney then getting a lot longer cook than I needed.

I reckon my initial set up is not optimal. Found a forum post from don Marco where he got a 225F holding overnight so I know it's something I've not got quite right.

Next time I go for a long cook I'll post up some pictures of how I've set my charcoal.