Something to Add to Your Power Options

[Lin]

http://ecoflowtech.com/?gclid=CLPXxsyQ0tMCFQ5qfgodKFQMZw

[Oonrahnjay]

http://ecoflowtech.com/?gclid=CLPXxsyQ0tMCFQ5qfgodKFQMZw

     Lots of power, lightweight, (price not stated), easy and quick.  My Daddy always told me "anything that's too good to be true -- probably is".

     Seriously, it's about 110 A/hr, which isn't bad, but they don't list depth of discharge ... or much of anything else.   But you can "Pre-Order" it!

[HB of CJ]

Yep.  What I see is fancy advertising that tells you nothing.  Only hype.  Like already said, how about a honest specification run down.

Apparently it is some sort of high tech battery?  What kind?  Would it not be funny to find it is just a packaged motorcycle battery pack?

Lead acid?  Chinese manufacture?  Just a redone UPS from over-run of available parts?  It almost tastes or smells of "too good to be true".

[Lin]

I got it as a link from a police supply company that markets a lot of things to the public.  They listed this on sale of only $599, but I think that website is selling it for $500.  If you click on the Pre order button there is a lot more hype and marketing but also a list of specs and prices.  Like many other things, it would seem that battery technology will advance and even become more affordable as time goes on.

[Jeremy]

If you look at the company's appeal on it's crowdfunding campaign page it says it's product uses Li-ion cells, which is what you would expect. They are almost certainly standard 18650 cells (as used in laptop batteries and cordless drills etc), frankly because engineering anything different would be both extortionately expensive and unnecessary - even Tesla cars still use 18650 cells in their battery packs, although Tesla is now in the process of developing their own cells.

It's entirely possible to build Li-ion battery packs of any size and configuration yourself using (for instance) cells out of new-old-stock replacement batteries for obsolete laptop models that you can buy on cheaply Ebay, and you can also buy on Ebay the BMS (battery management system) circuit boards you need to incorporate into the packs (because Li-ion batteries are dangerous things if overcharged).

I've built some fairly modest packs myself for my electric bike, but if you look on Youtube there are people building monster packs for all sorts of interesting and ambitious projects such as off-grid homes and home-built electric cars. So you could quite easily build the equivalent of this River product yourself if you really wanted to

Jeremy


Here's the crowdfunding page for the startup company behind River: https://www.indiegogo.com/projects/river-your-mobile-power-station-solar-generator-battery-powerbank#/

[Oonrahnjay]

...

It's entirely possible to build Li-ion battery packs of any size and configuration yourself using (for instance) cells out of new-old-stock replacement batteries for obsolete laptop models that you can buy on cheaply Ebay, and you can also buy on Ebay the BMS (battery management system) circuit boards you need to incorporate into the packs (because Li-ion batteries are dangerous things if overcharged). ...

you could quite easily build the equivalent of this River product yourself if you really wanted to

Jeremy

     You "could".  I'm not sure "I could".  Look at Chris and Cherie -- two *very* tech savvy people who tried Li-ion batteries.  It appears that they're moving into a place where they've been successful with it but success has been slow and ex$$$pensive.  They've tried all sorts of battery configurations, controllers and chargers, inverter/charger settings, etc.  It's still new technology for large battery banks (and I consider 10 8D AGMs a large battery bank and that's what some people would need to replace), there's not a lot of agreement on how to do it, and mistakes (the ones that don't result in fires big enough to bring a Boeing down) cost a lot of money.
     Will this little "suitcase" be a useful tool for some people?  Probably (if it works at all).  Does it look like something that will help me -- I dunno ...

[Jeremy]

     You "could".  I'm not sure "I could".  Look at Chris and Cherie -- two *very* tech savvy people who tried Li-ion batteries.  It appears that they're moving into a place where they've been successful with it but success has been slow and ex$$$pensive.  They've tried all sorts of battery configurations, controllers and chargers, inverter/charger settings, etc.  It's still new technology for large battery banks (and I consider 10 8D AGMs a large battery bank and that's what some people would need to replace), there's not a lot of agreement on how to do it, and mistakes (the ones that don't result in fires big enough to bring a Boeing down) cost a lot of money.
     Will this little "suitcase" be a useful tool for some people?  Probably (if it works at all).  Does it look like something that will help me -- I dunno ...

Yes I completely agree, building big battery banks using Li-ion cells (or any flavour of small rechargeable cell) is a different kettle of fish altogether. I'm not sure, for instance, how you deal with individual cells going bad (as they do) when you have literally hundreds of them wired-up together.

The River thing is quite a small device by comparison and probably only contains a couple of dozen cells - I think if I wanted something of that size for a specific purpose I'd certainly make my own, but if you want the sort of general purpose device which the River is aiming to be (with all it's multiple sockets and ports etc) then you'd either buy a River or wait 6 months until Ebay is flooded with cheap copies of the River that do all the same things for a quarter of the price

Jeremy

[Geoff]

I don't see how this device is related to bus conversions​.  Like I said about home built alternator generators​, this is for tent camping.

--Geoff

[windtrader]

There is a lot of technical considerations to lithium battery technology. Chris@technomadia was an early adopter of lithium for a bus conversion. I read his blogs and he did learned as he went so to speak, failing to manage some of finer technical considerations. Plus, costs were higher than now. Once I get my bus, I do plan on doing the analysis whether lithium batteries, solar panels, generator, electrical draw, etc. is something to pursue.

The key reason for using lithium is the power to weight ratio is higher than lead acid, a critical factor in ebikes and ecars. In a 18 ton commercial bus context, I'm not sure if a few hundred pounds makes much difference, especially considering the costs. My interest lies more in whether you can power the bus off batteries for all needs except extended interior air conditioning use. It seems like you might be able to charge up the batteries with panels than use the genset to top off where panels fall short. That is on a daily basis; maybe it might work but need to do all the calcs to make an educated guess.  Nice to see another ebiker here.

[Uncle Augie]

Yes I completely agree, building big battery banks using Li-ion cells (or any flavour of small rechargeable cell) is a different kettle of fish altogether. I'm not sure, for instance, how you deal with individual cells going bad (as they do) when you have literally hundreds of them wired-up together.

The River thing is quite a small device by comparison and probably only contains a couple of dozen cells - I think if I wanted something of that size for a specific purpose I'd certainly make my own, but if you want the sort of general purpose device which the River is aiming to be (with all it's multiple sockets and ports etc) then you'd either buy a River or wait 6 months until Ebay is flooded with cheap copies of the River that do all the same things for a quarter of the price

Jeremy

So im new here, take that for what it is worth. MechEng for much of my professional life, have always been a tinkerer. Lipo, specifically Lithium iron phosphate batteries are the best solution for power for a BUS Conversion. THere are different rules than Lead Acid, which is where people get into trouble. I am in the midst of finishing a conversion started by another and will be adding 18.4kW of Lipo batteries. Yes they need to be temp controled to work at optimal efficiency(both heat and cold are bad for them) So what is the solution? Using a battery pack with everything built in. Ill be using a Chevy Volt battery pack/heating/cooling system, Charged with Solar, using a gen set as a backup. Ill be able to have full time AC and Refrigeration all run off Solar and the battery.

How?

The AC will be a mini split system that uses an inverter to run a Variable Frequency to control the 3phase compressor motor, this allows the compressor to run at slower speeds continuously, and ramp the startup removing the high amp draw. Systems like this run on as little as 250watts to keep the Bus cool. Refrigeration will use a super insulated top loading freezer with a modified temp controller to allow it to run as a refrigerator. This will use about 500-800watts per day.

So between AC and refrigeration Im looking at 7000 watts or 7kW say 40% over head will give me 9.8kw usage per day. Ill be installing 320w panels on the top of the bus, 8 total. If you multiply the 320 watts the panel produces by the number of hours of full sun you get in a day, you'll get the amount of kwh that panel produces per day. The average roof in the United States gets about 4 hours of usable sun per day. We know the sun shines more than 4 hours, but "full sun" is a measurement that combines all the parts of the day when the sun is lower in the sky into one number. Using 4 hours of full sun, gives you this equation: 320 watts x 4 hours. That's 1.28 kWh (1,280 watts) in a day per 320-watt panel. If you multiply 1.28kWh per panel by 8 panels, you'll find that Ill produce about 10.24kW on an average day, that is just about enough to keep up with my AC demands on a day that I use the AC 24hrs a day.

Now we have to think about the fact that i need to heat/cool the battery pack. The system to keep the battery pack at a constant temp is built in. It uses a glycol jacket around the individual cells to carry away excess heat, or cool the packs when they get too hot. yea that takes a bit more electricity, so in all likely hood on days that i run everything all day ill have to run the 7kW generator for less than 30min or so to top off the battery bank.

Yes this is different than the usual setup for a Lead acid battery system, but it will weigh less, last longer, and keeps me from running the generator, in the long run it will save money and allow me to run the AC all the time.

[windtrader]

Welcome Augie,

one noobie to another, re bus conversions. Guess this thread is still OT. You've done more calcs than I have so I'll watch with interest. General comments on a few variables.

1) Panels mounted on a bus flush are going to be less efficient than permanently aligned panels. It is going to be atypical for roof mounted panels to be optimally aligned even with adjustable mounting.

2) AC consumption varies greatly depending on ambient temperatures. The Dometic and Coleman roof AC specs indicate power consumption of around 1700 watts. BTW - this is the one that offers the greatest challenge for full self-power solar operation. At 200 watts, that is hardly cooling much.

3) Freezer at 800. I'd buy that one. Recently ran a test on an old standalone freezer and it uses about 1k/day.

4) What about the water heater if electric?

5) Even with full LED lighting, there will be measurable usage if a late night person.

6) What about TV, sat box, etc?

7) What about cooking with electric cooktop?

Parasitic draw from the ubiquitous wall warts, etc.

I do like the approach of using auto cells as they must solve many of the environmental considerations. I've not done any pricing estimates but used ecar modules are certainly available now. If building my own packs, there are several choices for cell chemistry, for a deeper dive.

A genset is going to have to be wired in an all ebus as my lifestyle will surely draw down the max stored. Using ecar cells will likely allow for faster charging so a gen can recharge fairly quickly.

Then the cost for lithium. My gut tells me a lot more than lead acid. I don't even know how much you'd need to spend on 5kw of deep marines. LOL

[Uncle Augie]

 Used battery packs from a Chevy Volt, including all the electronics you need to run them are 1500-3000, That is for 19kwh and 1.2kwh = 100amp hours. SO one Chevy volt battery pack will replace 14 100ah lead acid batteries. Cost isnt the issue but weight is, the difference will be in space needed and weight.

I understand about the optimal orientation, and was planning on an adjustable mount. 8 cells is about all you will get up there. Luckily I live in the northern half of the country, heat always means a full sun day.

As for the power use, the Mini splits using an inverter to slow the compressor will actually only run at 250watts if needed. They are not like the AC systems that you have that run full power then shut off. Cycling on and off, rather the newest designs will run the compressor at a slower speed if they can maintain the temp. Yes running full blast they consume about 1.7kw of energy, but slowes only about 250 watts.

Ill post progress as i go. THe Bus has no interior, which for many would be a problem, but I build furniture/cabinets/ship interiors for a living out of my own woodshop.

[Iceni John]

I have eight Sharp 255W panels on my bus, all on individual hinged support frames.   When stowed against the roof they are at 21 degrees down, but they can be raised to level, 21, 33 or 45 degrees up.   This means that if I park the bus due east or west, the panels on the south side remain down, and the other side's panels are raised according to latitude.   21 degrees just happens to be about right for SoCal here, and I wouldn't be anywhere further north in the winter to need panels more than 45 degrees up.

I plan on having a 12K minisplit heatpump in the front and a 5K window A/C in the bedroom.   If it's hotter than what they can cool, then it's time to move!

John     

[Uncle Augie]

I plan on having a 12K minisplit heatpump in the front and a 5K window A/C in the bedroom.   If it's hotter than what they can cool, then it's time to move!

John     

why the 2? 12k should be more than enough to cool the whole bus into the upper 70's even when it is in the 90's and full sun. It isnt like you need the 60's, all you really need is a 10-15degree drop from outside temps to make it comfortable.

[windtrader]

why the 2?

Why do many coaches have THREE? I really doubt 15k btu for the entire coach is sufficient if ambient is north of 90.