NiCad Bank or Lead Alum. And What controller / Charger would be a good one?

[randall]

I want to build a test system with about 500w of panels and see how it goes. If that works out I want to upgrade to a larger system. The goal is to take a small data center off grid. It's a very small data center. Pulls about 2000 watts 24/7/365. If that works then the house is next. I don't have 10k to drop on this project. It will all be DIY and I will love every second of it! My skill set is good. I have worked with component level electronics for many years and understand AC wiring. The Battery technology is the only hold up. If I could get NiFe cheep or go purchase solid state Lithium Ion "not available or cheep" I would. I don't want to watch my Lead Acid decay and my money melt. I want a 10+ year battery solution now cheep. So.. This is what I have come up with.....

1. Build NiCad banks. I have access to an unlimited amount of small NiCad used cells for free. I have been playing with them and can pulse zap them and they work great. I think I can cut up copper pipe and build tube banks easily. It would allow for proper cooling and I can fuse each 7.2v bank. I could build hundreds and hundreds of these tubes and scale to any level. I have seen NiCad run away in Aircraft systems it i'ts pretty aggressive. I would want to design to protect the bank from this event.

2. Recondition golf cart batteries which have solid lead plates. High voltage over current /cycle clean the sulfate then flush and clean the cells. Convert to Lead Alum. I have access to these for about $0.25 / lb and I can cherry pick. There is no limit to the quantity available. I really like this chemistry. Easy, Cheep, Allows for a deep discharge and non corrosive to the battery. I have converted a test battery and it works well. I am surprised you cant purchase Lead batteries this way.

Both options are very affordable to me. But what charge controller do I use? I don't want to build one. I would like controllers to be chained together to expand the system as needed. I have found NiCad controllers but they are small. The Lead Alum batteries can run way down and don't want a invert to cut them off like a Lead Acid. It would be nice to find a controller that can be switched between the two. I can configure the batteries any way that is needed. Cost is not a concern when it comes to the batteries as they are basically free.

Am I crazy?

[Sunking]

Extremely foolish plan. Why do you want to volunteer for a 500 to 1000% electric rate increase with frequent outages silly? You never take anything off-grid if you have commercial power. It is economic suicide and extremely unreliable. I desin and build data centers. I also design off-grid solar systems for Cellular telephone companies with no access to commercial power, over 200 of them in 12 years. 25% of those have been decommed because commercial power became available.

But to answer your question you are Crazy and there is no Solar Charge Controllers made for NiCd batteries, and used batteries are boat anchors asking for big trouble. Geese 500 watts of panels for a 2000 watt load 24 hours a day is just plain ignorant. That is more than a very large luxury home uses in Miami with Air Conditioning set to meat locker temp. Try more like 18,000 watts with a little 22,000 pound battery in your pocket you get to replace every few years. Just plain Crazy talk. You forgot to add in a 20,000 watt diesel generator and 48 volt 400 Amp rectifier for an additional $40,000 and a 500 gallon storage tank for fuel. Let's not talk about all the Employment Prevention Agency permit fees, annual inspections, spill containment for the batteries and diesel fuel required for such silliness.

I think we are done here. I just saved you over $150,000. Well more than that because you need a new climate controlled building to hold 22,000 pound of toxic waste of batteries. So add another $150,00 or more. .

[Mike90250]

First, why do you think you can homebrew a better nicad pack than the FAA certifies ? I know I can't, and I doubt you can either.

A 2Kw datacenter ? Have you run out the math to see what size PV array is needed for ideal sunny days in mid-winter for your site ? Say maybe 4 good hours to harvest 50Kw of power (assuming no loss) That's about a 14Kw array. Then figure what's needed for a week in the worst month, There are stickies in the off-grid section covering all this.

I'm glad you are optimistic, because I am not.

The old Trace C-20 thru C-60 controllers had a ni-cad setting, but it was a simple algorithm, not the newer ones developed in the last 30 years.

[randall]

Sunking.
I am looking for a controller. That's all. I really don't care what you build and how much money you use to do it. I want to play with different battery options and I don't see controllers for Lead Alum or NiCad. Yellow Stone is using "USED" NiCad batteries. Toyota donated used Prius batteries. You obviously don't understand the durability of NiCad chemistry. I saw a West-Wind corporate jet the other day with 30 year old NiCad cells that keep passing annual. Maybe you should call Yellow Stone National Park and tell them they are idiots. You could tell them about all the data centers you build. You might get a sale.

Here is a link http://www.greencarreports.com/news/...-national-park

Nothing like a flamer who pumps their chest and brags about them selves.


Mike90250
I have not done the math on the 2k server rack. The 500w system is just a test / play. I want to see if this works before I spend the money on a larger system. I appreciate the input on the C-20 C-60 charge controllers. Is there anything out there for Lead Alum chemistry?

[Sunking]

Sunking.
I am looking for a controller. That's all. I really don't care what you build and how much money you use to do it. I want to play with different battery options and I don't see controllers for Lead Alum or NiCad.

Why can't you find them? Because there is no market for them. No one woul duse NiCd for solar. Too expensive, extremely toxic, and just as expensive to dispose of. Even if you could find them, you would many of them. because you cannot find a 400 amp controllers. Deisign and make one yourself is the only option. Shoul dnot cost you more than $10,000 and as many hours.

Yellow Stone is using "USED" NiCad batteries. Toyota donated used Prius batteries.

Toyota was smart, took their losses, took a tax writeoff to minimize liability losses. NiCd's are th eworse possible choice you could make for EV's. If you really understood NiCd batteries, you would understand why.

You obviously don't understand the durability of NiCad chemistry.

Been working with large scale wet NiCd's for over 40 years professionally. How about you?

Look large format NiCd cells are horrible. The economics suck, efficiency really sucks, and extremely expensive to dispose of. Toyota wanted no part of it. They did what they did to satisfy the Employment Prevention Agency and California whacky 0 emission emission policy. Apparently it is OK with EPA and California at the time to use toxic waste a slong as it does not exhale Co2 like we do.

To use them in Solar my friend requires almost twice the panel power. No problem if it liquid fueled rockets using unlimited dirt cheap commercial AC power and sky is the limit military no budget. NiCds are no longer used in Rocket Engines or Torpedos motors because they SUCK. Ex Navy nuke guy, here and we used them 35 years ago in antique WW-II torpedoes using a nuke reactor to top them off. Today all internal combustion engines are used. They use to be used in Telecom where I came from in special applications requiring very high discharge rates from small capacity. Sort of like the Saturn V booster of the 60/70's before you were born.

NiCd has been replaced with Lithium Ion and you can use any off the shelf controller if you use LFP batteries as they are drop in replacement for Lead Acid.

Educate yourself my friend. If you do not want to listen to me, then listen to Mike and others that are going to pile on. You are not going to get th eanswer you want to hear because it would be LIES or Ignorance.

[SunEagle]

I want to build a test system with about 500w of panels and see how it goes. If that works out I want to upgrade to a larger system. The goal is to take a small data center off grid. It's a very small data center. Pulls about 2000 watts 24/7/365. If that works then the house is next. I don't have 10k to drop on this project. It will all be DIY and I will love every second of it! My skill set is good. I have worked with component level electronics for many years and understand AC wiring. The Battery technology is the only hold up. If I could get NiFe cheep or go purchase solid state Lithium Ion "not available or cheep" I would. I don't want to watch my Lead Acid decay and my money melt. I want a 10+ year battery solution now cheep. So.. This is what I have come up with.....

1. Build NiCad banks. I have access to an unlimited amount of small NiCad used cells for free. I have been playing with them and can pulse zap them and they work great. I think I can cut up copper pipe and build tube banks easily. It would allow for proper cooling and I can fuse each 7.2v bank. I could build hundreds and hundreds of these tubes and scale to any level. I have seen NiCad run away in Aircraft systems it i'ts pretty aggressive. I would want to design to protect the bank from this event.

2. Recondition golf cart batteries which have solid lead plates. High voltage over current /cycle clean the sulfate then flush and clean the cells. Convert to Lead Alum. I have access to these for about $0.25 / lb and I can cherry pick. There is no limit to the quantity available. I really like this chemistry. Easy, Cheep, Allows for a deep discharge and non corrosive to the battery. I have converted a test battery and it works well. I am surprised you cant purchase Lead batteries this way.

Both options are very affordable to me. But what charge controller do I use? I don't want to build one. I would like controllers to be chained together to expand the system as needed. I have found NiCad controllers but they are small. The Lead Alum batteries can run way down and don't want a invert to cut them off like a Lead Acid. It would be nice to find a controller that can be switched between the two. I can configure the batteries any way that is needed. Cost is not a concern when it comes to the batteries as they are basically free.

Am I crazy?

There aren't any solar chargers for NiCad batteries.

Used FLA or any lead acid batteries have usually given up over half their lifespan. You can get some small % of charge out of them but I wouldn't bank on them working when you need them to.

Finally running anything that uses 2000watts 24/7/365 from solar will require close to 10,000 watts of solar panels and a 48volt 2000Ah battery system. That is not a small system.

[Sunking]

Sunking.
I am looking for a controller. That's all.

Read my lips. They don't exist.

[littleharbor]

Finally running anything that uses 2000watts 24/7/365 from solar will require close to 10,000 watts of solar panels and a 48volt 2000Ah battery system. That is not a small system.

Numbers subject to change depending on location.

[Sunking]

Numbers subject to change depending on location.

Yep 10,000 watts was a low ball number only a few places like Phoenix and sunny CA where there are no clouds or humidity and points further south. 4 Sun Hour day in Winter is realistic and that takes 18,000 watts with FLA and 24,000 watts with NiCd. Want an outdated PWM controller? Even higher. If he did the math he would know better than to even ask such a crazy question. He did ask if he was Crazy or not. He got what he asked for.

[SunEagle]

Numbers subject to change depending on location.

Agreed. It was a simple calculation that would use 50% of the battery system on sunless days. A better solution would be double the panel wattage and battery Ah rating.

[randall]

I will reach out to the team that Installed the Yellow Stone setup and see how they are charge controlling their NiMh banks. I was hoping there was something already out there. I have found some charge controller programmed chips for NiCad and NiMh which can be adapted into a larger setup. I can flash the chips for other chemistries. Perhaps I could modify the firmware on an existing controller. The Lead Alkaline solution looks good too.

I really don't want to start from scratch here. I may need to find a more technical electronics based forum for these questions. NiCad and NiMh have strong advantages over lead Acid. NiCad and NiMh can be restored and used for years with proper battery conditioning. It is not uncommon at all to see them running strong with 20+ years of use. When Lead Acid or Lithium ion are worn out they are just done. Lead Alkaline I have little experience with but non corrosive chemistry will defiantly extend the life of the battery.

I absolutely love the Edison Nickle Iron batteries. I purchased a antique used one on eBay that was almost 90 years old and it works perfect! If I did give up on NiMh / NiCad and Lead Alkaline what are the best ones to purchase and has the price came down?

We can all argue about how much solar, how many watts. How big the battery bank must be. I have not looked into any of this. All of these variables are well understood and can be properly calculated. When I am ready to scale up to a project that needs this resolved I am sure this forum will be a great place to gather that information from people who are experienced in this with real world installations.

Right now the limiting factor for Solar power is energy storage not panels. panels are almost free at $0.50-$0.75 / Watt. Seriously who buys solar trackers anymore? Right now the Battery is the problem not the Panels. Power companies have figured out they don't want to compete with roof tops and have been lobbying to get solar incentives taken away from users with great success in many states. This trend will only continue.

I am a little crisp from the flaming attacks but now I know there is nothing "contractor available" for these chemistries.

[SunEagle]

I will reach out to the team that Installed the Yellow Stone setup and see how they are charge controlling their NiMh banks. I was hoping there was something already out there. I have found some charge controller programmed chips for NiCad and NiMh which can be adapted into a larger setup. I can flash the chips for other chemistries. Perhaps I could modify the firmware on an existing controller. The Lead Alkaline solution looks good too.

I really don't want to start from scratch here. I may need to find a more technical electronics based forum for these questions. NiCad and NiMh have strong advantages over lead Acid. NiCad and NiMh can be restored and used for years with proper battery conditioning. It is not uncommon at all to see them running strong with 20+ years of use. When Lead Acid or Lithium ion are worn out they are just done. Lead Alkaline I have little experience with but non corrosive chemistry will defiantly extend the life of the battery.

I absolutely love the Edison Nickle Iron batteries. I purchased a antique used one on eBay that was almost 90 years old and it works perfect! If I did give up on NiMh / NiCad and Lead Alkaline what are the best ones to purchase and has the price came down?

We can all argue about how much solar, how many watts. How big the battery bank must be. I have not looked into any of this. All of these variables are well understood and can be properly calculated. When I am ready to scale up to a project that needs this resolved I am sure this forum will be a great place to gather that information from people who are experienced in this with real world installations.

Right now the limiting factor for Solar power is energy storage not panels. panels are almost free at $0.50-$0.75 / Watt. Seriously who buys solar trackers anymore? Right now the Battery is the problem not the Panels. Power companies have figured out they don't want to compete with roof tops and have been lobbying to get solar incentives taken away from users with great success in many states. This trend will only continue.

I am a little crisp from the flaming attacks but now I know there is nothing "contractor available" for these chemistries.

If the NiMh banks are really a worth while path to follow then maybe look into how they were charged in the EV they came out of.

My guess is that those used batteries were obtained along with a charging system from the car manufacturer. Otherwise someone came up with a garage engineered charger for those batteries that is not available on the open market and maybe for a good reason if it does not meet IEEE or UL standards..

[GuyMark]

Hi Randall.

As others have pointed out, there are a few "iffs and buts" here, but to answer your question rather than lecture you, yes there are charge controllers which will do the job at a push. https://www.ebay.co.uk/itm/Flexcharg...-/291761124566 This one currently on sale is good for a 24v (20 cell) Nicd and has a charge output of 25A with a charge voltage of 31v.

I found them for sale in the US too - in fact I think that is where these controllers are made. https://webosolar.com/store/en/searc...submit_search=

Not a bad match for your 500W panel. You can also buy a 12v version (300w nominal) or a 48v one (1.2KW). the higher voltage the better the value.

You will end up with a very substantial solar array to service a mean 2KW load. If you had (TRULY) unlimited storage and didn't have to worry about self-discharge, then if you could average out sunshine from the seasons, you would probably want SOMETHING along the lines of a 20KW array if you are in the UK, I guess it varies wildly from State to State.

If you are in Florida then things become a bit more doable as it seems fairly close the equator and seasonal daylight variation should not be too bad. It's a REALLY grim rule of thumb BUT if you derate the panel by 90%, that is not far off what you get if you average out day, night, summer, winter, cloud & sunshine.

So a 10KW array will, depending on position probably generate something like 8,776KWH - BUT - and this is the huge BUT - you might do extremely well with a 20KW array from mid spring through to mid autumn. But then due to short days and long nights, be woefully out of power the other half of the year if you are too far from the equator.

If you have, for example, a week of grotty heavily overcast / rainy weather at the darker part of the year, you really might be struggling to get the panels yielding more than perhaps 1% on average - 6 hours of perhaps 4-5% output and then 18 hours of nothing at all either due to darkness or excess cloud.

At this point, unless you have batteries capable of storing hundreds of KWH then putting a fixed load of 2KW onto solar is going to be a fantasitcally expensive project - as during the darker months, you are going to need a gigantic array of panels.

Awesome position in Florida or nearby and this MIGHT be doable MOST of the time with perhaps SOME sort of fallback device - grid or genset. Would GUESS you might still be needing around 20-25KW worth of panels though as well as enough storage for at least 48 hours of ghastly weather. - 100KWH battery bank?!

I like the idea of lead-alum - and have played with that a little myself. I was given a heavily sulphated but fairly new car battery and after forcing it to take power and a dozen cycles or so later, it started to come back a little. More of a "see what happens" that any real need to salvage a scrap battery.

Adding a tiny amount of cadmium sulphate helped - though not the easiest compound to purchase. Eventually removed and stored the electrolyte, flushed and went with an alkaline solution. Worked surprisingly well and had more than enough "grunt" to start a diesel van. Problem of course is that lead-alkaline has a lower discharge and charge voltage so rather than faff about, it was only a short term experiment on the van. Some years on however the battery still does sterling work as a starter battery for a diesel genset - test it once every month or so, run for fifteen minutes and **** down. Battery trickle charges from a 5w panel. So yes, lead alum is an interesting cell and plate corrosion seems non existent. There IS a company manufacturing them I think in China but of course transport is an issue.

I have never tried converting a new lead acid to a lead-alkaline, might be worth a cheapo

[GuyMark]

Have tried to post some comments but struggling to make it work, will try a much shorter post with a link to some controllers for Nicads.

https://webosolar.com/store/en/search?controller=search&orderby=position&orderway=desc&search_query=nicad&submit_search=

Hope this time it goes through.