New to forum - DIY batteries discussion

[Headrc]

Hi folks, I am new to this forum and joined because I am contemplating building a solar setup for my workshop. I am a member of other forums that are heavily involved in building powerwalls out of Lithium battery technology. I am getting the impression that this forum favors lead acid type batteries for solar power storage ...and that is due to safety of overcharge etc. I also do not see a lot of activity in building your own battery out of individual Lithium or Lifepo4 cells here ....and again I assume that is because fo safety issues and cost? If I do pursue this project for my small workshop I can go either way as I know the process of building my own batteries out of Lithium cells fairly well. I have done it for my electric mowers, power tools etc. I also have quite a few deep cycle 55AH AGM batteries if I were to pursue this using the older battery technology. I am not certain I will do actually install solar because the cost might not be justified compared to what I normally pay for electric for this shop, but I am always looking for better ways to do things in life. Hence my joining this forum and acquiring more knowledge. Thanks in advance. Richard

[SunEagle]

Hello Headrc and welcome to Solar Panel Talk

I understand you may have the knowledge and experience with building batteries and can contribute to this forum.

I just ask that you try to make sure other members understand there are dangers and they need to be careful with what they do.

[Headrc]

Hi SunEagle ...will do!

[organic farmer]

Hi folks, I am new to this forum and joined because I am contemplating building a solar setup for my workshop.

Welcome



I use lead-acid batteries. The general assumption is that somewhere between 5 and 10 years down the road you will be replacing your batteries. You can always change at that time.

[Sunking]

I am getting the impression that this forum favors lead acid type batteries for solar power storage ...and that is due to safety of overcharge etc. I also do not see a lot of activity in building your own battery out of individual Lithium or Lifepo4 cells here ....and again I assume that is because fo safety issues and cost?

Richard you are correct, it is economics that do not work. A good high quality Pb battery cost 1/2 to 1/7 of an equivalent of say a decent LFP (aka LiFeP04) and a good quality Pb battery last a lot longer than any Lithium battery.

Taking anything off-grid at a minimum is going to cost you 5 times more than buying it from the POCO for the rest of your life using Pb batteries. Why would anyone with half a brain tied behind their back opt for Lithium and cause power to cost 10 to 30 times more than buying it from the POCO. You would have to be a brainless fool to do that. Adding to it you would be a fool even selecting Pb batteries if POCO power is available. Not only will you NOT SAVE ANY MONEY, but going off-grid also makes you one heavy a$$ Polluter with a Monster Sized Carbon Foot Print, and empty pockets.

[Mike90250]

Most folks don't have the spot welders needed to connect up cells in massive parallel / series arrays. Each connection has a failure risk and by adding hundreds of failure points, the chances of a happy success, get lower.

And since the many flavors of Li batteries have different requirements, all those variables need to be considered along with overcharge and deep discharge problems that can destroy a Li battery

[Headrc]

Exactly why I joined here folks. Thanks for this feedback. There are other views on the Powerwall forums I belong to. They are very involved with harvesting used cells, testing them and building powerwalls. But that is very labor intensive. However, with that said I am a believer in the applications I have currently used Lithium for which is basically mobile power for different devices. Again I have built several batteries for this and won't go back to Pb for those applications. Soldering can be successful ...and I even built a spot welder out of a 12 volt battery, car solenoid, welding cable and a chinese timer. I just finished that and so far it looks like it will work quite well for my current application. There are of course plug and play cells too like the Headway Lifepo4 that just bolt together. All of the Lithium technology is more expensive than Pb though ...except maybe if you are willing to go through all the harvesting, testing etc. that these guys are doing with used cells. for powerwalls. So according to Sunking here ....., if POCO is available ....solar does not make sense financially. I have not done a financial analysis yet ...but with that from a user who is very experienced at solar ...that exercise seems pointless.

[Sunking]

Exactly why I joined here folks. Thanks for this feedback. There are other views on the Powerwall forums I belong to. They are very involved with harvesting used cells, testing them and building powerwalls.

That is not a Powerwall, it is a Hack anyway you spin it.

However, with that said I am a believer in the applications I have currently used Lithium for which is basically mobile power for different devices.

You just hit the nail on the head, and may not realize what you just summed up. Lithium batteries have very useful applications. Especially where the application must be mobile, compact, light as possible, highest energy densities available, and you are willing to pay way up for that. Example an EV would not be practical without lithium and you can justify the expense. Other applications like cordless power tools, Land Mobile Radio HT's, Medical Equipment, and other demanding applications.

None of that is required or needed for a fixed solar system and even some mobile applications like RV's that have the space and carry the weight. Add on how much more dangerous, expensive, and short lived lithium is makes no sense to use in a fixed solar application. Until economics flip, Pb will remain default choice of smart money.

[Headrc]

I get it ....and again this is why I joined here ....thanks

[sdold]

I get it ....and again this is why I joined here ....thanks

That's a great attitude, some folks leave in a huff when they don't get the answers they want to hear, and miss out on valuable info. No forum is perfect but this one has the highest truth/BS ratio I've seen on any forum.

[Headrc]

Yes I agree ... I do my best to try and research something before I dive into it. The other forums have great info that I have learned a lot about building batteries and I have benefited from it greatly. But I was a little pessimistic about the whole large powerwall/solar idea and then found this forum. Glad I did! On the other side though ...I highly recommend learning about the do's and don'ts of building your own lithium batteries for mobile applications. It beats Pb or other technologies like Ncd hands down in that application IMO. And you will pay dearly buying prebuilt Lithium batteries.

[Guest]

I am getting the impression that this forum favors lead acid type batteries for solar power storage ...and that is due to safety of overcharge etc. I also do not see a lot of activity in building your own battery out of individual Lithium or Lifepo4 cells here ....and again I assume that is because fo safety issues and cost? If I do pursue this project for my small workshop I can go either way as I know the process of building my own batteries out of Lithium cells fairly well. I have done it for my electric mowers, power tools etc. I also have quite a few deep cycle 55AH AGM batteries if I were to pursue this using the older battery technology. I am not certain I will do actually install solar because the cost might not be justified compared to what I normally pay for electric for this shop, but I am always looking for better ways to do things in life. Hence my joining this forum and acquiring more knowledge. Thanks in advance. Richard

As for as I known, Lead-Acid battery normal cycle life is about 300 ~ 500 cycles at most. LiFePO4 can be 2500 and faster charger time.

[SunEagle]

As for as I known, Lead-Acid battery normal cycle life is about 300 ~ 500 cycles at most. LiFePO4 can be 2500 and faster charger time.

Actually a premium FLA type battery can handle over 1500 cycles if you keep each cycle to less that 25% DOD.

LiFe type may get you more cycles and then again may not depending on how they are discharged and properly charged.

As far as I am concerned FLA still get you more cycles/$ spent then any other chemistry. Sure Li will get you more cycles but at a much higher cost the Lead.

[sdold]

I had a 4700 AH 12V AGM battery installed in 2003, it's cycled every day 5-20%, and it's still going. This one is probably atypical but you can get a lot of cycles if you don't abuse them.

[TRA]

Hi folks, new guy here. Maybe you can help me make a choice?

I am setting up a 3.2kw 48v array. Midnight Classic controller, AIM 6kw 120/240 IC. I am contemplating two battery options. 4 Renogy 12v 200ah AGMs, or a single SimpliPhi 48v 69ah battery. From what I understand, the pro's of LiFePO4 are a deeper discharge and more cycles. The AGMs cost half, and deliver more energy if I don't drain them past 50%.

What should I do here? Pay the price for the smaller capacity? Go with the AGM, and replace with LiFePO5 down the road when the costs may be better?