# Battery question



## soyer38301 (Jul 27, 2017)

I just purchased a small 800 watt solar system that I can expand as time goes by. I was pricing batteries and soiling myself at the cost lol...

I was just informed that our maintenance company for work is coming out to replace all the batteries in a large UPS in our router/telecom room. This UPS is on our generator circuit and the batteries have never really even had a load on them except for the few seconds it takes for the genny to kick in.

I know they are 12 volt but have no idea of the brand. If I can get them cheap or free I am thinking worth it even if they are no longer top notch...

Is my thinking sound? Or has old age addled my feeble brain?

Thanks

Sent from my SM-G892A using Tapatalk


----------



## Chiefster23 (Feb 5, 2016)

Free batteries? Man, I would jump on that in a heartbeat!!!


----------



## soyer38301 (Jul 27, 2017)

Chiefster23 said:


> Free batteries? Man, I would jump on that in a heartbeat!!!


I am hoping they dont blow me some environmental crap (it is Illinois after all). Cause if memory serves me correct I think there are 12 batteries in that unit. Would be sweet!

Sent from my SM-G892A using Tapatalk


----------



## budgetprepp-n (Apr 7, 2013)

That's the batteries I'm using I was told they wouldn't work for solar but mine work great.

I even called the company that made the UPS batteries and they said NO ,,But they work fine

This guy sells a ton of the UPS batteries for solar use ,, The gray ones in the bottom left of the picture are
the ones I use (all gray)

This is were I get my stuff in Ohio this guy has 1,000s of solar panels also (good prices)








https://akroncanton.craigslist.org/for/d/solar-batteries-agm-94-amp/6664319714.html
they weight about 100lb each


----------



## BookWorm (Jul 8, 2018)

I've used 12V deep cell marine batteries and 6V golf cart batteries tied in to make 12V. Both worked ok, but two deep cell 6V golf cart will last longer than one deep cell Marine grade.


----------



## soyer38301 (Jul 27, 2017)

I used some deep cycle marine batteries in a wind setup I had...they didnt last long 

Sent from my SM-G892A using Tapatalk


----------



## budgetprepp-n (Apr 7, 2013)

I have some Uncle Wally deep cycle batteries that have been working since 2012 and they seem fine


----------



## paraquack (Mar 1, 2013)

I used golf cart type batteries in my RV. With proper care and feeding, they lasted 12 years. Yes there was a gradual decrease in output, but they did everything I needed.


----------



## soyer38301 (Jul 27, 2017)

I think some of my issues with batteries is the inverter took them down too low before shutting off. That won't happen this time around.

Sent from my SM-G892A using Tapatalk


----------



## Chiefster23 (Feb 5, 2016)

I only started fooling with solar 3 years ago so I’m still learning. But I’ve read that having more than 3 strings in parallel is prone to uneven charging. That said, if I could get free batteries I wouldn’t worry about that And connect up whatever I needed to store the required power. 

On that note, I used to work for a railroad that converted a diesel locomotive into a battery powered switcher as an experiment. They used hundreds of OPTIMA 12 volt batteries connected in series-parallel. It was a big failure. They could never get the battery bank to charge evenly so they cooked many batteries and the entire bank would never charge up to full capacity.


----------



## budgetprepp-n (Apr 7, 2013)

I have 15 batteries that are wired in series. I also have three charge controllers. The batteries are all tied together and I sort of have them separated in a way.
Every fifth battery has a controller hooked to it. Positive on one end of the pact and negative on the other so no charge goes in unless it passes
through all five. I have a hydro tester of some kind that looks like a glass turkey baster with a floating gauge thingy inside and they
all look even when I check them. I don't know if that's the correct way or not but it seems to work. The batteries are about 5 years old now but seem fine.
I keep the voltage up as much as I can and they don't seem to need much water.


----------



## soyer38301 (Jul 27, 2017)

I think as long as you don't cook them the water level should be good. Some will evaporate over time, but cooking them is bad. I plan on having a diversion load (already have the device from my wind project) hooked up even if it never kicks in. Better safe than sorry 

Sent from my SM-G892A using Tapatalk


----------



## Chiefster23 (Feb 5, 2016)

Why do you need a diversion device with solar? Your charge controller is supposed to control the charging rate and stop charging when the battery is fully charged.


----------



## Chiefster23 (Feb 5, 2016)

budgetprepp-n said:


> I have 15 batteries that are wired in series. I also have three charge controllers. The batteries are all tied together and I sort of have them separated in a way.
> Every fifth battery has a controller hooked to it. Positive on one end of the pact and negative on the other so no charge goes in unless it passes
> through all five. I have a hydro tester of some kind that looks like a glass turkey baster with a floating gauge thingy inside and they
> all look even when I check them. I don't know if that's the correct way or not but it seems to work. The batteries are about 5 years old now but seem fine.
> I keep the voltage up as much as I can and they don't seem to need much water.


15 batteries in series? If they are 12 volt batteries then you have a 180 volt battery bank. Where did you get an inverter that can use 180 volts?


----------



## soyer38301 (Jul 27, 2017)

Chiefster23 said:


> Why do you need a diversion device with solar? Your charge controller is supposed to control the charging rate and stop charging when the battery is fully charged.


Because I felt the need, but that is with all my experience with a wind generator and a hand made controller. Still learning so...if I say something that is wrong please feel free to correct 

Sent from my SM-G892A using Tapatalk


----------



## Chiefster23 (Feb 5, 2016)

No, no! I am not correcting, just asking. I am still learning too. But I have no one local to talk to about solar so I get all my instructions from articles and you folks on line. So I am asking because you posed something new I never heard of and I’m interested.

I have been thinking about using a diversion device in my own solar set-up to take advantage of every last available watt of power. On a sunny day, after my batteries are charged, the controller goes to “float” and I’m wasting available power. I am thinking of installing a diverter and sending that excess power to my hot water heater. My heater already has multiple heating elements installed so it would be an easy job to isolate and use one for this excess power and help reduce my electric bill in the process.


----------



## soyer38301 (Jul 27, 2017)

Understood. The original controller that came with the wind setup had diversion built in. It was just plain cheap and didn't last long. 

So I used the horseshoe shaped heating element from the controller and attached it to a xantrax c60 that I set for diversion. In that setup it was needed.

In a solar setup (from what I have read anyway) instead of going to float it would use the extra power for something. Dont know what yet, but sumpin... 



Sent from my SM-G892A using Tapatalk


----------



## Chiefster23 (Feb 5, 2016)

Got it! My electric hot water heater is my most power hungry appliance so that is my logical choice for a diversion device.


----------



## Elvis (Jun 22, 2018)

Chiefster23 said:


> Got it! My electric hot water heater is my most power hungry appliance so that is my logical choice for a diversion device.


You can buy 12v, 24, and 48v heating elements that fit hot water heaters on E-Bay but you've got to be careful that you don't overheat the water tank and pop the relief valve. Some people who have a 2 element hot water tank replace one of the 240v elements with a 12v element and set the 240v thermostat about 10 degrees cooler than the desired water temperature so that at least there is always some warm water on cloudy days. There are controllers that monitor the tank's temperature and if the tank gets too hot the controller than sends the excess power to a different load. Not something I've played with but I know it's available.


----------



## Elvis (Jun 22, 2018)

Chiefster23 said:


> 15 batteries in series? If they are 12 volt batteries then you have a 180 volt battery bank. Where did you get an inverter that can use 180 volts?


Got to admit I'm also curious about what his system voltage is. But I suspect he's got 3 strings of 5 batteries each wired in parallel running a 12v system. Assuming that the charge controllers don't communicate with each other having a separate charge controller hooked to each string may minimize the damage normally seen when running multiple strings.

Since he doesn't know how to read his hydrometer we can't ask him how balanced his SGs are but I suspect the answer may be interesting in a bad way. I wonder if any of his cells use an excessive amount of water compared to the others or if he has compared the amp draw on each of the 3 strings.


----------



## Elvis (Jun 22, 2018)

soyer38301 said:


> I just purchased a small 800 watt solar system that I can expand as time goes by. I was pricing batteries and soiling myself at the cost lol...
> 
> I was just informed that our maintenance company for work is coming out to replace all the batteries in a large UPS in our router/telecom room. This UPS is on our generator circuit and the batteries have never really even had a load on them except for the few seconds it takes for the genny to kick in.
> 
> I know they are 12 volt but have no idea of the brand. If I can get them cheap or free I am thinking worth it even if they are no longer top notch...


Industrial UPS batteries are usually nickel-cadmium. They last a long time if you don't cycle them too often so perfect for UPS systems but instead of lasting for thousands of cycles they are usually only good for a few hundred cycles. So yes, those batteries are probably fine for playing around with solar but if you cycle them daily don't expect them to last for years.


----------



## budgetprepp-n (Apr 7, 2013)

Chiefster23 said:


> 15 batteries in series? If they are 12 volt batteries then you have a 180 volt battery bank. Where did you get an inverter that can use 180 volts?


Ok I screwed that up ,, Wired in parallel


----------



## soyer38301 (Jul 27, 2017)

Well dang...service dude came out yesterday and they don't need to replace anything 

He did say he would keep an eye out for anything I might be able to use...guess I'll just have to pony up some cash for now. Can always add to the bank later.

Sent from my SM-G892A using Tapatalk


----------



## Chiefster23 (Feb 5, 2016)

I put my solar system into service in 2015. Rolls and Trojan batteries are very expensive and we have no local dealers so shipping is crazy. I bought Crown golf cart batteries from a local guy thinking that they would be fine. Now only 3 years later these golf cart batteries are showing a significant decline in capacity. I have taken extremely good care of these batteries never discharging more that 25%. Never overcharging and water checked monthly. So I am disappointed at the performance I got for the money I spent. I am satisfied with all my solar components except the batteries. Battery technology and costs suck.

This is part of the big lie from the green energy crowd. There is no good cost effective way for a homeowner to store power for when the sun doesn’t shine and the wind doesn’t blow. So most people grid-tie so the end result is very little reduction in power plant emissions.


----------



## Elvis (Jun 22, 2018)

Many people kill their 1st set of batteries early through lack of knowledge and maintance, I did. Over or under filling, chronic over or under charging, running too many strings of batteries ect. so it's suggested that for a 1st set of batteries you buy a decent quality but not the high dollar batteries. With 800 watts in panels I'd suggest either two L-16 sized 6v batteries wired in series (about 400 amp hrs at 12v) or a few large 12v batteries wired in parallel.

If you go with the more expensive AGMs there is a lot less maintance but AGMs usually die a year or 2 faster than a properly maintained LA battery LA batteries have caps on top so you can fill with distilled water every month or two. Do not overfill, Just add water until the water is just below the plastic tube that extends into the battery cell. Overfilling is how I killed my 1st set of batteries after about 5 years.

Batteries require a certain charge rate to last as long as possible, The charge rate should never be less than 5% of the batteries 20 hr rated capacity not over 13% of the rated 20 hr capacity. If you charge too slow you never stir the electrolyte and if you charge to fast you overheat the batteries,
With 800 watts in panels you're probably going to see about 51 amps at 12v. (800 watts x .77 derail rate = 51 amps at 12v output) so if you want to charge those batteries in the sweet spot (10% charge rate) you're going to need about 510 amp hrs worth of batteries. At a minimum you need at least 357 amps in batteries to avoid charging too fast and overheating the batteries. The most in batteries you want is about 1000 amp hrs at 12v to at least stir the electrolyte occasionally. (all calculations based on the battery's 20/hr rate)

With a 51 amp expected maximum charge rate I hope that kit came with a charge controller that can handle that much amperage and accepts at least 8ga wire for the output to battery side. 
@sover38301


----------



## Chiefster23 (Feb 5, 2016)

I’m good now. 1000 watts of panels. 600 amp hrs of batteries. (Six 6 volt, 205 amp-hr batteries. 3 strings of 2 batteries). Crown recommended 50 amp max charge and I have my controller set for that but my batteries only see that rate at mid day on sunny days. If anything, my batteries were undercharged during their first 2 years as I started with 400 watts of panels, then 600 watts, then 800 watts. I only went to 1000 watts and a bigger charge controller recently.


----------



## soyer38301 (Jul 27, 2017)

Got the pole barn buttoned up so hope to be putting the solar in over the next couple weeks. I'll post as I go.

Sent from my SM-G892A using Tapatalk


----------



## Caribou (Nov 11, 2018)

Never mix batteries of a different age or type in the same battery bank. If you buy new batteries buy them at or about the same time. If you are given old batteries or buy new one put them in a separate bank. Your battery bank is only as strong as the weakest battery so mixing an old battery with a new one will drain the new battery down to the level of the old. Multiple banks is fine but you will need a separate charge controller for each bank or, more likely, a way to switch from one bank to the other.

I went with a 48V system but a 12V or 24V system works well. Decide which way you want to go before you start buying parts as it will cost a bit to replace everything if you change your mind.


----------

