diy solar

diy solar

Are there any LiFe batteries that just "Work"? (a bit of a vent)

toms said:
Well, this is a forum where there is a thread with hundreds of replies on how to compress cells based on a manufacturers recommendation that is basically made up. You can make it as simple or complex as you wish. 15 years ago it wasn’t possible to find examples of systems that were built to last - now there are plenty of examples, all sharing common themes.
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Correct me if I'm wrong but Winston is quite expensive compared to most. I guess yours has lasted because you got what you paid for.
I have a big advantage with my climate control. In 10 years I have never seen 75 or 65 degrees, it's always around 69-71.
 
You can only work out the price/kwh of your system when every component has failed.
No point paying half price for a system that outputs a third the power over its lifespan.

Plenty of focus on upfront cost, as with a lot of things though - you get what you pay for.
 
toms said:
No point paying half price for a system that outputs a third the power over its lifespan.
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Empirically, yes.
toms said:
You can only work out the price/kwh of your system when every component has failed.
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Right. But you can work out predictively at what time point a failure would create a cost equal to the percentage another component is expected to last. But that’s merely one factor.

In my case because my initial solar costs enabled an over $1000/month savings it ‘paid for itself’ in essentially one month. KWh costs were irrelevant. Further, the cost four years ago to go lithium would have prevented my ability to reduce costs.
Not only that my system has met 100% of my needs for four years- now well past the break even of Pb vs. Li factored for time.
I’m all for lithium especially at scale, but in practical terms lead acid got me going snd has sustained me affordably for several years.
So I’m naturally of the opinion lead acid has a place. Not one versus the other, but rather the right batteries and system for the application.
 
For sure every application is different. I’m dealing with typical off-grid house systems - so average 20kwh/day, no grid availability.
 
toms said:
15 years ago it wasn’t possible to find examples of systems that were built to last - now there are plenty of examples,
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Those cheapo LiFePo 100 and 200Ah batts Will just featured…. Dang. At those prices and if I keep them watm…
Next winter I should be a half mile away and 400 feet higher- no grid nearby. I hope to heat primarily with wood, with propane just being the daytime six days while I’m at work. November through Jan/Feb I’ll need batteries I can belt hard with a generator/charger occasionally. Those will take that beating no problem. Still, $2100 gets my attention as an expense even though it’s worth it. To get the powerco to plant poles 3/4 mile just isn’t in my bank account.
 
toms said:
For sure every application is different. I’m dealing with typical off-grid house systems - so average 20kwh/day, no grid availability.
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This is not what the OP wants but I'm interested. His ship doesn't come in for a while so maybe he will forget about this hijack. :LOL:

Can you share with us which of the Winston choices available today would you choose for your 20kwh/day.
A "brief" on why that battery or batteries would be cool. Not asking for a "white paper".
 
WYtreasure said:
This is not what the OP wants but I'm interested. His ship doesn't come in for a while so maybe he will forget about this hijack. :LOL:

Can you share with us which of the Winston choices available today would you choose for your 20kwh/day.
A "brief" on why that battery or batteries would be cool. Not asking for a "white paper".
Click to expand...

I’ve only used the wb-lyp200aha, as the price was right. I recommend sizing your batteries at 150% of maximum overnight use. I have parallelled up to 3 of them with no issues.

Why these batteries are good is that they are proven. Other batteries may be better value, five years from now i may have a different opinion.
 
Will Prowse said:
Yikes, I would actually have to disagree here. I had to maintain FLA packs for years, and had quite a variety of AGM. They are pretty pathetic, overall.

If you hit low voltage disconnect with the BMS, you should set your inverters LVD to a higher voltage. The BMS should be used as a last resort safety mechanism. This way, you will never have to reset your battery with any special type of charger.

If you cannot power a load with your pack, you bought a low quality pack. They should pull the advertised current rating without issue. We test this all the time on my channel, and most pull what they are rated to. What type of load are you running? If inductive, you should oversize the current capacity of your bank. For solar, it is typically less than .1C, so it should be fine. Your battery is too small.

OCPD in lifepo4 is a fantastic safety feature that lead acid packs do not have. Unless you add your own, obviously.

What overwhelms me is dealing with sulfation and shorted cells. And higher internal resistance. And lower coulombic efficiency. And equalize charges. And voltage sag.

Do you really prefer lead acid? I just cannot see the logic here.
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Set inverters LVD to a higher voltage
 
Rednecktek said:
I'm just terrified that the heaters will completely drain the batteries and they'll be a $2000 paper weight. That's a LOT of cat food to risk, ya know?
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There is an easy and inexpensive solution to this. Put the heaters on the cheapest model (65A) Victron Battery Protect. It's $60 on Amazon. You can set the cutoff voltage, and if the battery falls below that level it will cut off the load (heaters in this case).

Without thinking real hard about it (and before my first cup of coffee for the day), it seems like you can also overcome your inverter's lack of a LVCO suitable for LiFePO4 by using a Victron Battery Protect. They have a 100A version and a 220A version, all available several places on the web (including Amazon).
 
I guess we've finally gone off the rails but this does bring back memories in the dark ages where the ops question could be changed to

"Are there any Pb lead-acid batteries that just work?"

The problem in most forum threads was defining work vs work-well, as in engineered for the application at hand.

Perhaps 10 percent calculated their daily loads first (with any desired autonomy), the panels needed to support that, and their solar-insolation hours to make it all work. And being savvy with hydrometers, equalization and other needed maintenance. Or in the case of AGM, not understanding how easy it is to UNDERcharge them on a daily basis walking them down in capacity - these were shunned by those who simply could not accept it.

However, the other 90% of Pb solar discussions involved reverse-engineering an op's TRUE setup, purposely lacking detail sending us on wild goose chases forever.

This revealed that in most cases, the user was applying zero knowledge, and slapping trash together to see what sticks. Or *purposely* using the wrong battery type for warranty-scams. The "I want a free battery for life" crowd.

The other major problem was an op trying to build a gigantic system with no knowledge at the outset, and being UNWILLING TO LEARN with a small starter system first so they can observe things first hand before spending kilobucks on gear. In many cases, forum responders were merely used as salesman with the "What's the best xxxx for this?" - and after a few responses, the op is never seen again. Mostly pitting forum responders against some sort of salesman elsewhere in the physical world.

The op (not here - this is just bad memories from the past) was merely pitting our knowledge against a salesman elsewere - the op not really desiring to learn anything, but just slap stuff together on the cheap.

Sorry - I guess one good rant deserves another. I'll stop.
 
Horsefly said:
one that the LVCO is adjustable.
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This was key for me. I have far more DC loads than AC loads. My inverter is setup to cut off at a much higher voltage than most because I need to save my power for my DC loads. I don't want my A/C to drain my batteries leaving me unable to keep my food from spoiling or losing my Internet access.
 
rmaddy said:
This was key for me. I have far more DC loads than AC loads. My inverter is setup to cut off at a much higher voltage than most because I need to save my power for my DC loads. I don't want my A/C to drain my batteries leaving me unable to keep my food from spoiling or losing my Internet access.
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(y)


My first solar build was for our family cabin in the mountains. Although there are a couple small DC loads, almost everything runs off the inverter. So I got used to the idea of using the programmable LVCO to keep the battery from going down too low. Then last year I helped someone upgrade from lead acid to LiFePO4 for their boat, where almost all loads are DC and the inverter is only used for a couple of things. That's when I discovered the Victron battery protect, which can do for the batteries for DC loads what the LVCO does AC loads.
 
GLC said:
Not really, I depend on my batteries and I have not had one issue at all. How much does peace of mind cost?
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We all depend on our batteries.
I have piece of mind and didn’t spend a 1/3 of what it would cost for those.
Mine have worked flawlessly for 18 months so far.
 
12VoltInstalls said:
Empirically, yes.

Right. But you can work out predictively at what time point a failure would create a cost equal to the percentage another component is expected to last. But that’s merely one factor.

In my case because my initial solar costs enabled an over $1000/month savings it ‘paid for itself’ in essentially one month. KWh costs were irrelevant. Further, the cost four years ago to go lithium would have prevented my ability to reduce costs.
Not only that my system has met 100% of my needs for four years- now well past the break even of Pb vs. Li factored for time.
I’m all for lithium especially at scale, but in practical terms lead acid got me going snd has sustained me affordably for several years.
So I’m naturally of the opinion lead acid has a place. Not one versus the other, but rather the right batteries and system for the application.
Click to expand...
PB definitely has a place as long as you know the limitations and do the maintenance required .
Specific Gravity test, Absorption charging, Bulk Charging and water fills get old.
Not to mention the venting.
 
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