Almico wrote:The inverter/charger I have is a Tripp Lite APS750. It is rated for 750W continuous and 1500W surge. It's not a car inverter.

Yes, understood. It's not a car inverter, but rather a camper inverter. It's still not designed with motor loads in mind. It's designed more for convenience loads, things you might find in a camper.

FWIW, I'd probably solve this problem by grinding doses at home with a bulk grinder, vacuum sealing servings individually according to brew method, and opening the packages on demand at the farmer's market. (If the Lido is okay for pourovers, maybe you only pre-grind for batch brewing.)

Bulk grinders and heavy. Inverters and batteries are heavy. There may be a more elegant solution. Maybe a Vario w/ steel burrs for the farmer's market instead of a bulk grinder?

I appreciate that. If I could find a way to avoid dragging this stuff, I would. But my purpose for the grinder is not grinding for brewing as much as it is grinding bulk beans when people purchase bags. My first week at the market I brought some whole beans and some pre-ground. The pre-ground that did not sell were thrown away. I'd prefer to bring only whole beans and offer the service of grinding a bag if necessary. I have a Preciso, but it takes 4 hoppers full and almost 5 minutes to grind a pound. That won't work and would likely kill that grinder in short order.

But you're right, it's a whole lotta work just to sell a few more bags of coffee. But I figure as long as I have it there I can use it to fresh grind brew coffee as well. I think the solar panels would attract some attention and send the right message to the farmers market crowd. I just opened an account with Baratza and should just order a case of Encores and sell grinders too.

FWIW, Tripp Lite inverters are on par with Xantrex. At only 750W my inverter weighs about 17#. http://www.tripplite.com/Inverter-Charg ... ets~APS750

The issue is 750W, with 1150W "Overpower" and 1500W "Double Boost", is just barely not capable of supplying the startup load for the grinder. It starts it up, sans beans, 90% of the time. The next one up in line, the APS1250, would likely do the job quite well, but I'd prefer not to spend another $400 at this point. I supposed I could eBay my 750 and kick in the difference. I'd rather stay with Tripp Lite since I already have the $120 remote switch/monitor.

This inverter will get it running without beans most of the time. When it doesn't, it just trips the overload and I would have to turn off the inverter and turn it back on. Not elegant, but it would likely do the job. Another workaround might be to just get the grinder spinning in the morning and leave it running all day (4 hours). It is very quiet without beans and would hardly be noticed.

Pedal powered grinding and brewing
http://www.velopresso.cc/about/

Or, how about a propane powered generator. I have no experience with these. So I have no idea if it's suitable or safe for your needs.

The only generator quiet enough is the Honda EU2000. I don't want to spend $1000 on one.

Funny you mentioned pedal power. I thought hard about hooking up a stationary bike to one of these:



and make them work for it. "And how badly do you want your coffee ground?"

.

Almico wrote:The only generator quiet enough is the Honda EU2000. I don't want to spend $1000 on one.

My Honda EU2000i is over 10 years old and just ... works. I can understand the reluctance to spend $1k on a genset, though.

However, there is always Harbor Freight ... they used to have the Kipor, which was pretty much an exact copy of the Yamaha. Now Harbor Freight sells this for $500: http://www.harborfreight.com/2500-peak2 ... 61171.html

I think we've strayed from the topic. Perhaps a topic split is in order, Mods?

You should be able to run a motor with capacitors on a modified sine wave inverter, otherwise known as the cheaper ones. Grabbing a cheap 2.5-3KVA inverter of that type should be inexpensive. Your solar panels should keep up with the charge required for grinding, but if the batteries are topped up when you head out they'll probably last the day without any sun too.

Almico wrote:I need to steal a brewing idea. I've recently started selling beans at a local farmers market and there seems a to be a big need for brewed coffee as well. I'm building a nice little 5 cone drip station for Hario V60s

I'll be using a Zojirushi CD-LTC50-BA for my hot water source and a Bonavita stovetop kettle for pouring. For the time being I'll be brewing directly into 10oz hot cups. I'm using my Baratza Preciso to grind one dose at a time, but am trying to get my brain around how to control the water. I can't use a scale under the drip station and not much use having one under the cup. Maybe I can use a scale under the Bonavida when I'm transferring water from the Zojirushi? The Zojirushi can maintain 208* water temp. Would I lose too much heat by only transferring one dose of water at a time? Or is it just a matter of practicing my pour technique precisely?

Her might be a little crazy but...if it's even possible to cut glass like this, you might be able to cut out a hole for the v60 to sit on and drip through?

http://vanityplanet.com/chefs-circle-di ... e-888.html

OldNuc wrote:There is a phase angle issue here and the KW meter will not see it as they only see true power. That is why they are not prohibitively expensive. Just get the steady state running load while grinding and the steady state load running and not grinding. To estimate the rated capacity of the inverter multiply the not grinding load by 3.5 or 4 if the physical weight of the inverter is low to get an idea of what is required. Copper and iron equates to reserve capacity.

Well here's a head scratcher. I hooked up the Kill A Watt meter to the Grindmaster 825. It says it's pulling a whopping 137W steady state without beans. It jumps to an astronomical 250W while grinding. But when I switch to current mode it shows it's drawing a little over 5A. That translates to 600+W to me. I'm confused.

Here's a vid of what it's doing:

https://www.youtube.com/watch?v=gP6Mb3_umuQ

.

That phase angle thing I mentioned. The voltage and current are shifted out of phase to produce the rotating magnetic field. The wattmeter does not understand this. You can read the current and voltage separately and get an idea of the total inverter load. P=EIcos(phase angle)

That's a pretty heavy load for a grinder. Just for giggles I checked my own Compak K10. With no beans grinding I'm pulling 245 watts, 4 amps, and a PF of 0.51. So that tells you right there that 1/2 the power is wasted on the motor phases. Likely it puts a heavy load on the inverter to keep the phases in cycle.