Building a solar generator

[JHZR2]

Originally Posted by Cujet

Originally Posted by thastinger

To be "portable" you're not going to run much of any load for very long as those LiFePo4 batteries can't go below a 70% SOD.

That just does not seem to be accurate. "Most lead acid batteries experience significantly reduced cycle life if they are discharged more than 50%, which can result in less than 300 total cycles. Conversely LIFEPO4 (lithium iron phosphate) batteries can be continually discharged to 100% DOD and there is no long term effect. You can expect to get 3000 cycles or more at this depth of discharge. " Of note: Draining a new 100AH LiFePO4 battery down 100% is not completely draining the cells. They generally have significant excess capacity until about 2500 cycles.

Originally Posted by BeerCan

Not sure if anyone is looking at this but I am going to post pics until it's finished :

Of course we are looking at it. Very cool project, BTW.

Reads like marketing fluff. I'd agree if it said 500-1000, but not 3000. I'd agree with 3000 at maybe 50-70% DoD. Now, many batteries come with much more energy than their nameplate, and since they have a bms in there, they can play in a narrower range of SOC - effectively self derating. If that's the case 3000 is more plausible.

 

[UncleDave]

Cool project. I tried using a magnum inverter and ended up going back to outback. Whats the "hybrid" part of that? What part of the system "owns" the charging algorithm? Is there limiting built into the battery? It looks like they batteries have a little SOC gauge built in. UD

 

[JHZR2]

Those batteries tend to have a bms built in for balancing, and the SOC indicator is a handy helper. LFP is too flat in terms of. SOC vs voltage to be trusted in that measurement. Bms will count coulombs and do other things to keep track.

 

[BeerCan]

Originally Posted by UncleDave

Cool project. I tried using a magnum inverter and ended up going back to outback. Whats the "hybrid" part of that? What part of the system "owns" the charging algorithm? Is there limiting built into the battery? It looks like they batteries have a little SOC gauge built in. UD

So the hybrid part is a pretty cool feature that I still have to test. say for example you have a honda 2000w gen set that can run an air conditioner fine once its running but cant make it through the start load. What this inverter will do is add power from the batteries to get you through the initial load. I am going to test this feature pretty soon, so we'll see how it works. Output box, gfi protected if I did it right

 

[UncleDave]

Originally Posted by BeerCan

So the hybrid part is a pretty cool feature that I still have to test. say for example you have a honda 2000w gen set that can run an air conditioner fine once its running but cant make it through the start load. What this inverter will do is add power from the batteries to get you through the initial load. I am going to test this feature pretty soon, so we'll see how it works. Output box, gfi protected if I did it right

Looking good- keep us updated, On Hybrid -thanks, thats where I though it was going- boost assist. The magnum model I tried out had this featured but wasnt labeled as a "hybrid" I wanted to be able to reliably kick over an AC with a smaller genset in a grooming van using this, but never got that far due to the unit shutting off at sustained full load. I asked about that feature from two other vendors and the answer I got back from both AIMS and Outback was that the downside to that ability was loss of certain certification because that was considered what was known as "Islanding" although I'll do basic work Im in no way an electrician so I dont know about this. Still curious about the charging profile. Thanks sir! UD

 

[BeerCan]

Originally Posted by UncleDave

Originally Posted by BeerCan

So the hybrid part is a pretty cool feature that I still have to test. say for example you have a honda 2000w gen set that can run an air conditioner fine once its running but cant make it through the start load. What this inverter will do is add power from the batteries to get you through the initial load. I am going to test this feature pretty soon, so we'll see how it works. Output box, gfi protected if I did it right

Looking good- keep us updated, On Hybrid -thanks, thats where I though it was going- boost assist. The magnum model I tried out had this featured but wasnt labeled as a "hybrid" I wanted to be able to reliably kick over an AC with a smaller genset in a grooming van using this, but never got that far due to the unit shutting off at sustained full load. I asked about that feature from two other vendors and the answer I got back from both AIMS and Outback was that the downside to that ability was loss of certain certification because that was considered what was known as "Islanding" although I'll do basic work Im in no way an electrician so I dont know about this. Still curious about the charging profile. Thanks sir! UD

Charging I set up for CC/CV at 27.8vdc it holds that voltage for 1 hour after the battery amps drop. It will go silent to 24vdc or 30% SOC as determined by the BMK (battery monitor). this is all subject to change of course. I hooked it up to run my network rack. It is stupid to do this now while connected to shore power but I wanted to give it a real life test and if the network goes down I will know immediately . I will see how long it can run before it switches back to mains. It will switch to mains at 30% SOC and switch back to batteries at 80% SOC Hopefully in the next week or two I will have this charging with solar. I am really interested in that scenario. BTW this picture made me realize I had gas cans near there. They are now moved

 

[UncleDave]

Sounds like you rolled your own as a single stage based on a high and low voltage. Did the batt manufacturer provide a stat sheet for the batt? Is the grey wire attached to the negative post a temp sensor ? Yeah prob good idea to move the gas cans....proximity happens more often than you'd think. UD

 

[BeerCan]

Originally Posted by UncleDave

Sounds like you rolled your own as a single stage based on a high and low voltage. Did the batt manufacturer provide a stat sheet for the batt? Is the grey wire attached to the negative post a temp sensor ? Yeah prob good idea to move the gas cans....proximity happens more often than you'd think. UD

Yes Lion provided the 27.8 value , they responded to an inquiry on the website in like 20 minutes on a saturday afternoon . https://lionenergy.com/products/lion-safari-ut-1300#specs grey wire is a tmp sensor, orange and blue are the BMK wires.

 

[UncleDave]

Originally Posted by BeerCan

Originally Posted by UncleDave

Sounds like you rolled your own as a single stage based on a high and low voltage. Did the batt manufacturer provide a stat sheet for the batt? Is the grey wire attached to the negative post a temp sensor ? Yeah prob good idea to move the gas cans....proximity happens more often than you'd think. UD

Yes Lion provided the 27.8 value , they responded to an inquiry on the website in like 20 minutes on a saturday afternoon . https://lionenergy.com/products/lion-safari-ut-1300#specs grey wire is a tmp sensor, orange and blue are the BMK wires.

Always awesome when a manufacturer gets back to you. Did they supply anything that looks like a discharge vs. soc curve? Interesting on the temp sensor. Cant recall what magnums instructions were. It's in the positive clamp of my ctek 2500, and outback wants you to mount near the positive terminal. On the gas can I just bit the bullet and moved to metal cans couldn't stand odor due to plastic being some tiny % permeable. UD

 

[BeerCan]

Originally Posted by UncleDave

Originally Posted by BeerCan

Originally Posted by UncleDave

Sounds like you rolled your own as a single stage based on a high and low voltage. Did the batt manufacturer provide a stat sheet for the batt? Is the grey wire attached to the negative post a temp sensor ? Yeah prob good idea to move the gas cans....proximity happens more often than you'd think. UD

Yes Lion provided the 27.8 value , they responded to an inquiry on the website in like 20 minutes on a saturday afternoon . https://lionenergy.com/products/lion-safari-ut-1300#specs grey wire is a tmp sensor, orange and blue are the BMK wires.

Always awesome when a manufacturer gets back to you. Did they supply anything that looks like a discharge vs. soc curve? Interesting on the temp sensor. Cant recall what magnums instructions were. It's in the positive clamp of my ctek 2500, and outback wants you to mount near the positive terminal. On the gas can I just bit the bullet and moved to metal cans couldn't stand odor due to plastic being some tiny % permeable. UD

No discharge curve or anything, I am expecting a follow up on Monday. The info they gave me was by text. Got the metal cans already https://www.bobistheoilguy.com/forums/ubbthreads.php/topics/5474000/gas-cans-nato-style#Post5474000 Here are magnums instructions regarding temp sensor

 

[UncleDave]

Good man on the metal cans. (I didnt mean for that to rhyme.) Interesting, I wonder why this discrepancy between vendors??? UD

 

[BeerCan]

Originally Posted by UncleDave

Good man on the metal cans. (I didnt mean for that to rhyme.) Interesting, I wonder why this discrepancy between vendors??? UD

Just found this in a different Magnum manual I was reading

 

[UncleDave]

I guess that makes sense, it would seem to me the positive terminal would run hotter but maybe not. Wishing you good successful Xfers..... We lost something in the rack every time we did a xfer from grid to back up power even through a UPS last fall when we had all the power outages in Nor cal. UD

 

[wrcsixeight]

Neat project, and definitely not cheapening out on the products. The one photo looking down at the 500 amp Deltec shunt and fuse, it looks like the 4/0 lugs might have 'ears' on the crimps below the thick wall adhesive heatshrink. How are you crimping these? I keep wanting to gain experience with Lifepo4, but have mastered the care and feeding of TPPL AGM's, and will wait on the fence for a few more years at least. To fellow readers, this article can show how far that proper wire termination can be taken, and one photo showing crimp ears: https://marinehowto.com/making-your-own-battery-cables/ https://marinehowto.com/marine-wire-termination/ I unfortunately own the HF hydraulic crimper he tests at the end of the first link, and they are as bad as he says. I've ground out some of the Dies for 2awg thick walled ring terminals, as the biggest dies labelled 0awg, only do 4awg somewhat adequately. Its a very clunky tool, but I have achieved quality results, taking abut 10 times longer than a proper tool would to achieve a better result.

 

[Cujet]

Originally Posted by JHZR2

Reads like marketing fluff. I'd agree if it said 500-1000, but not 3000. I'd agree with 3000 at maybe 50-70% DoD. Now, many batteries come with much more energy than their nameplate, and since they have a bms in there, they can play in a narrower range of SOC - effectively self derating. If that's the case 3000 is more plausible.

There is no question that many quality batteries are "sandbagged" (under-rated) but the reality is that these batteries are showing excellent resilience in real world uses. Tesla does this kind of under-rating also. That way, after 100,000 miles, range reduction is on the order of 10%, and not 30%.

 

[BeerCan]

Originally Posted by wrcsixeight

Neat project, and definitely not cheapening out on the products. The one photo looking down at the 500 amp Deltec shunt and fuse, it looks like the 4/0 lugs might have 'ears' on the crimps below the thick wall adhesive heatshrink. How are you crimping these? I keep wanting to gain experience with Lifepo4, but have mastered the care and feeding of TPPL AGM's, and will wait on the fence for a few more years at least. To fellow readers, this article can show how far that proper wire termination can be taken, and one photo showing crimp ears: https://marinehowto.com/making-your-own-battery-cables/ https://marinehowto.com/marine-wire-termination/ I unfortunately own the HF hydraulic crimper he tests at the end of the first link, and they are as bad as he says. I've ground out some of the Dies for 2awg thick walled ring terminals, as the biggest dies labelled 0awg, only do 4awg somewhat adequately. Its a very clunky tool, but I have achieved quality results, taking abut 10 times longer than a proper tool would to achieve a better result.

Ha. I used that exact website to make my cables and I use the FTZ tool he suggests. I read that article top to bottom highly suggest and thanks for sharing those links, I should have done it.

 

[wrcsixeight]

The FTZ crimpers are a tool I covet, but can't justify purchasing. I'll just grind out Hex sizes for the size cables / Lug sizes I desire of the clunky HF hydraulic crimper's undersized dies, but it would be nice to have a template to etch on the dies before I bust out the grinder and files.