MPPT boost - 24vdc to 48v battery bank

[psyfy]

if the battery bank is not in use i'm sure you would probably be able to charge it up 1/2 at a time.

as to the pvs, you aren't going to get around the rewire, but it isn't as complicated as you make it sound.

1/2 at a time? Thanks but it's a muck around with a 50kwh battery. CC's like the Midnite current sources right, so 12v@~100a=1200w, 24v@~100a=2400w & 48v@~100a=4800w.
So 48v will adequately cover the C10 recharge rate but 24v will take twice as long. At $5- a Gallon of Gas for the 10kva genset, that makes a bit of a difference.

Though does it really matter? Nah! Just being pedantic I guess.

[psyfy]

Yeah, this still may happen but it is just not high on the list.  There are too many more important things to do at the present time and not enough resources (engineers) to get it all done.

I thought that  solarconverters.com   made what you want but I just looked and theirs is 12V to 24V.  There are other companies out there that must do this if you can't wait.  I just don't know where right off the top.


boB

I hope so.

Hey, I been having a chat with some others and realise that I also have the option to rectify 110vac(RMS) to 154vdc @ 40a (~4kw). Tell me, which input on the Classic (and which model) will take this input.

Is the output from the Classic to the Battery bank PWM?
What would be the charge rate for 154dc@40a?
Is the Classic configurable as a 'Constant Current Source' so that 'Max Amps' can be defined?


Thanks.

[dgd]

However, the concept of the  LITE Classic with all the display, setup and logging  software done externally is the future.. 
Just need the iphone app, a simple version of the local app that shows Classic activity 

dgd

Already easy to do this with VNC.  I run Remoter on my iPhone and can access the Local App anywhere, anytime.

yes, I already do this and it really works well. Its just the local app running on the 'home' laptop disconnects too often for my liking.
Also also just too many 'unresolved features'.
An iphone app just showing the meters part would be good for me.
dgd

[mtdoc]

yes, I already do this and it really works well. Its just the local app running on the 'home' laptop disconnects too often for my liking.

Hmm.  I haven't had any disconnect problems.

Also also just too many 'unresolved features'.
An iphone app just showing the meters part would be good for me.
dgd

I agree a simple iPhone app would be fun.   

For me I want to access more than just the Classic data.  Nice to be able to monitor my whole system -- Inverter, Grid/genset and AC usage data, etc - also my weather station data.  Now. if I could just get all that to run on a Raspberry Pi - I'd have a really low cost, low power solution.

[Photowhit]

if the battery bank is not in use i'm sure you would probably be able to charge it up 1/2 at a time.

as to the pvs, you aren't going to get around the rewire, but it isn't as complicated as you make it sound.

1/2 at a time? Thanks but it's a muck around with a 50kwh battery. CC's like the Midnite current sources right, so 12v@~100a=1200w, 24v@~100a=2400w & 48v@~100a=4800w.
So 48v will adequately cover the C10 recharge rate but 24v will take twice as long. At $5- a Gallon of Gas for the 10kva genset, that makes a bit of a difference.

Though does it really matter? Nah! Just being pedantic I guess.

You have an AGM battery which has the characteristics of a low self discharge 1-2% per month, so You need just 40 ampshours at 24V to fully charge per month, It would take less time than reading this thread to reconfigure your bank, unless it is lead casted.

Furthermore, since your charging the top 5% of the battery capacity, you won't/shouldn't be charging at C10 and since your applying such a low current, you really don't need super heavy cables, if that's what your worried about.

If I've followed this thread correctly you just want to maintain/top off the battery and you have no applied loads. Sounds like your making a mountain out of a mole hill.

[dbcollen]

"so You need just 40 amps at 24V to fully charge per month"

Please use the right terms when giving advice, 40 amp HOURS is what is needed, not 40 amps per month, 40a/month would be 28800 amp hrs. I am not trying to be pedantic here, but it is important to use the correct terms to avoid confusion.

[Photowhit]

I am not trying to be pedantic here,....

Well, you certainly are, ...but your also correct! I changed it.

Thanks, just seems like the OP is trying to make this a big complicated thing, when it doesn't take much to maintain AGM batteries.

[psyfy]

If I've followed this thread correctly you just want to maintain/top off the battery and you have no applied loads. Sounds like your making a mountain out of a mole hill.

Hey thanks Photo-what-not! Now listen, I'll paint you a picture whilst I sip my morning coffee...

1.) The property is in Trinidad, CO. It's already two floors up, with a third to go on. You guys have heavy snow this year too right???

2.) I am currently in Australia and return in June. In contrast, it was nice, mild 107F here on Friday. I travel a lot, too much in fact, not enough time at home where the Buffalo roam etc. In fact, the last 18 months have been spent backward and forward to Frankfurt, Valencia, Austria, Prague and many other places.

3.) Besides the weather being a partial issue, the person babysitting the CO property isn't really the one to go around doing a rewire of batteries or a panel reconfig on the roof. Aside from the four feet of snow and 4F temperature, my grandfather is 87 next week.

4.) However, he could install a new CC as he was an engineer "back in the day" (don't think even the Mayan calendar goes back that far ) but he's not so quick on his feet these days, if you know what I mean. At least the battery part of the 'shed' is heated. Actually, he'd love it if I asked him to do it.

5.) 48v/1200Ah (48*3.2v/400Ah cells) of LiFePo4 batteries arrive in June. Can't wait to build the BMS for it as a lot of the stuff on the market is just crap. To use one would be like entrusting Charles Manson to babysit your kids. A BMS really only has three tasks, Undercharge, Overcharge and Cell Balancing. It's how it is done that counts and the quality of the design. Mine's based on a Atmel AT16. Got a tape reel of those things and need to keep coming up with creative, non wasteful ways to use them. SMD and not PTH IC's you see.

6.) The 48v/1000Ah VRLA AGM's will be retired and sold off. That is already a done deal. Naturally, I want to keep them in shape.

7.) Two weeks ago, I had someone (an installer) from Denver drive down there to sort it all out, said he could do it when I spoke with over the phone from here. Well, he couldn't work it out. Probably because among other things, I run a modified an APC UPS10000 10KVA UPS as the main inverter with another 1000watt SineWave inverter running through the AC input of it.
Here's how it works... When the small inverter output sags below 90vAC, a custom uP based design of mine disables it's H-bridge, it shuts down and the 10KVA UPS takes over within 20ms. All equipment remains blissfully unaware of the changeover.
When the load on the 10KVA UPS drops below 10%, the same logic re enables the small inverter. The UPS sees AC on the AC input and graciously hands controll back to the 1kw inverter. As an aside, I designed the UPS into the as I bought it from a client for $100. Increased the surface area of the heatsinks so that it could deal with continuous full loading if required.
I mean, wouldn't you do the same, if you knew what you doing?
There are a few other tricks such as the AC coupling of two 3kw Grid-Tied inverters (that I repaired, they cost $35- each from eBay) facing the UPS/inverter during daylight hours. However, that is an entirely different story. I only mention it so that you may better understand that it is not so easy to just go about reconfiguring the system in my absence.

8.) Finally, I'm a Mechatronics Engineer (B.Eng(Mechatronics) who's speciality is embedded systems, microcontrollers and PLC's. I also code some desktop apps in .NET(C#) with SQL (of course. At the moment I work with data telemetry designs.

9.) Yesterday I bought a Classic LITE 150 to hack about with. Why not I though. Sure, it doesn't boost as the literature frustratingly lead me to believe but hey, who does...


To backtrack... I didn't paint a picture to begin with as frankly, when last on this forum it was my day off and I don't really have much time... and yes, it's true, Vaporware irks me. 22 years in the electronics/computing/design industry has made me bitter. hahaha


Anyway, there you have it, nine points of rambling. Hope that is enough to silence the bitches!

[Photowhit]

The truth will set you free,

I don't want to try to follow what is going on with your system.

It appears I have answered questions for the "vaporware" questions, so... If you consider them "bitches" don't look at me, I think the wasting of my time would entitle me, but let a community solve real problems, and it works...

[cpm]

As one of the 'bitches', I suppose,

I have nothing to add.

[psyfy]

As one of the 'bitches', I suppose,

I have nothing to add.

hahaha. No problem, all good. So I'll leave it there and add to the body of knowledge when there is something worthwhile to contribute...

Over and out.

[dgd]

The truth will set you free,

I don't want to try to follow what is going on with your system. nny

Funny that, I had two smartly dressed people at my door telling me the same thing..

It appears I have answered questions for the "vaporware" questions, so... If you consider them "bitches" don't look at me, I think the wasting of my time would entitle me, but let a community solve real problems, and it works...

Good point.  But I suppose we did learn, yet again, that the Classic is an ongoing development project.  No boost. And no resourses at Midnite  to add this functionality any time soon. 

We did get some interesting off topic discussion about reporting software and cpu hardware. Much better than other message threads that descended into hard liquor or worse still 'the dogs' complete with dog pics 

dgd

[dgd]

As one of the 'bitches', I suppose,

I have nothing to add.

hahaha. No problem, all good. So I'll leave it there and add to the body of knowledge when there is something worthwhile to contribute...

Over and out.

No, please don't become a lurker again.
Maybe let us know about your ideas for a  LiFePO4 battery management system when you start designing it.

dgd

[SolarMusher]

Much better than other message threads that descended into hard liquor or worse still 'the dogs' complete with dog pics

Great!
Post sheep pics if you prefer...
Erik

[dgd]

Much better than other message threads that descended into hard liquor or worse still 'the dogs' complete with dog pics

Great!
Post sheep pics if you prefer...
Erik

Don't get me wrong. I was not complaining, I actually quite enjoyed the diversion to the dogs that you started with those excellent pics of your
'pack'. I, for one, like to see some of the 'bigger' picture including lifestyle and interests of others in this business. I just wish I had some of your snow and ice here right now, the heat here is too much...

dgd