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Are my batteries going to float too soon?


ace
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Hi everyone.

I'm new to the forum, as well as new to solar & I'm in need of some advice. I'm hoping someone can help with a few questions I have & point me in the right direction.

I'll try give you as much detail as I can in order to make things easier..... This might be a long post, so my apologies in advance

Due to various issues with the municipality, I've been forced to go totally off grid. With no other viable alternatives, I decided to go solar. 

Firstly, my setup consists of:

8 x JA Solar JAP6-60-265 24v Solar Panels (4 parallel sets of 2 in series)

16 x Royal Deltek 105ah Calcium Lead 12v Batteries (4 parallel banks of 4 in series)

1 x SOL-I-AX-5M 5000VA/4000W Inverter Charger

I'm using a gas geyser, gas stove,  a small A-rated energy fridge and have also installed 12v led lighting throughout the house.

I use a DC-DC converter (Meanwell) to take the 48v battery bank down to 13.8v for all the 12v stuff (lights, alarm, electric fence, router, camera's & gate motor) <--- each have their own 12v battery.

After doing lots of reading here on the forum I decided to install the custom firmware update (LC1 73 00C) made by some of the members here. (HUGE shout out to them - Great work!)

The update went smoothly & Im happy with the update (love the display now). Anyway here are my inverter settings for reference:

(1)=Uti (2)=60A (3)=All (4)=nor (5)=uSr (6)=Lrd (7)=ted (8)=50hz (11)=20A (12)=48v (13)=54v (16)=Snu (18)=bof (19)=KEP

(20)=Lon (22)=Aof (23)=Byd (25)=Fds (26)=58.4v (27)=54v (28)=SnG (29)=44v (30)=onE (31)=SbE (32)=Aut (38)=di S  

I use very little power at night, perhaps 200w/h with tv running (+-3hrs max). Current draw from the DC-DC converter averages about 2A with most of the lights we commonly use on.

When I go sleep, the inverter shows about 5w of usage, jumping up to 65w when the fridge kicks in. Very little current draw from the dc-dc with all the lights off (+-800ma)

During the day, I have more than enough power and Im totally content with that. However at night I feel like my batteries are draining too fast.

By sunrise I've noted my batteries to be sitting at 49-49.5v, by about 6.45, they gradually start charging..... so far all seems good.

By roughly 9am the batteries are at 58.4v taking in about 17-18A of current. At about 10am the inverter shows them to be fully charged & has changed to float which is set at 54v.

If I run my Generator with the panels while the inverter is charging in bulk mode, the batteries will take in about 30-35A, but then they go into float a lot quicker too.

Overall I feel like my batteries aren't lasting as long as they should considering the rather low drain on them. I somehow feel like they aren't being charged correctly.

Without knowing too much about batteries, I've tried my best to do my own research, but I seem to find many different views on this. Hence the following questions.

1) What is 50% D.O.D for my current battery bank. Is 49v ok? Am I draining them too low to expect a reasonable life from them?

2) Is it normal for my batteries to be fully charged by 10am already? Is the inverter switching over to float too soon (even though I updated the firmware)?

3) Is 58.4v the correct bulk voltage for calcium lead batteries? Do I need to charge them at a higher voltage.

4) Is 54v the correct float voltage for calcium lead batteries? (I've read it should be 55.2 elsewhere)

5) I've read a bit about equalising the batteries, is this recommended? If so, at what voltage & how frequently should this be done?

6) Should these batteries ever reach gassing while charging? (I've heard a ever so faint bubble or two when putting my ear up against them) but not really gassing as such.

7) Do I perhaps need more panels to charge the batteries at a higher current? Tested this with a genny & they did accept more current, but also went into float earlier & didn't make any diffs overnight.

8) Does it seem normal to be at about 49v in the morning considering my low draw? Am I expecting too much from these batteries?

Thats about all I can think of for now, I'll probably remember another question after I've posted this (murphy!)

But I'll appreciate any informed feedback on my setup I can get as I really don't want to waste my money by not looking after these batteries.

Thanks in advance.

 

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Hi Ace, welcome.

Two things that pop out for me:
1) 16 x Royal Deltek 105ah Calcium Lead 12v Batteries are UPS batteries, maybe 250 cycles to 50% DOD. You must NOT use them hard.
2) to protect the batteries, get a BMV Battery Monitor ASAP. Keep them above 80% at all times, higher if you can.

Sorry for the bad news re. the batts. But rather you know about it now rather than +-8 months from now when you have to replace the bank because no-one told you it cannot take a off-grid solar load. 

Rest will comment on all else.

Edited by Guest
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1 hour ago, ace said:

Overall I feel like my batteries aren't lasting as long as they should considering the rather low drain on them.

I feel bad your first post with not so good news ... maybe not +-8 months, maybe +-2 years, all depends on how they are used. The are designed for UPS'es to stay on float 99% of the time, use sparingly the 1% so that and after +-5 years they die of old age ... in the UPS, still on float. :-) 

They are NOT deep cycle batteries, not designed for solar use. Sales people do not know the difference. Sorry.

Cycling them daily in a solar application shortens their life cycle fast. And to keep 16 of them balanced is a fine art. But the guys have the solution for that.

The good news: Use them as best you can, as long as you can thereby learning everything about batteries. Your money is not wasted. Call it school fees with a steep learning curve ahead to make them last. Next set will be nirvana compared, I promise. 

BMV Battery Monitor will help you manage the bank for peak performance. 

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Thanks for your input Triplett.

Are you sure about these batteries?

Take a look at this: https://www.rectifier.co.za/Batteries/ROYAL/Royal spec sheets/1150K.pdf

If that isn't false advertising then I really don't know what is.

8 Months..... ?

Sorry...... I need a minute to pick my heart up off the floor.

Ok, so if these batteries aren't quite up to the task i require, What would be a safe voltage to take them down to in order to see 2 years life?

 

 

Edited by ace
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3 minutes ago, ace said:

Are you sure about these batteries?

Jip, know them very well. For UPS batteries they are solid, sold a lot of them at one stage, never doe solar. Only Trojan and only the Trojan RE range. 

See, I also started with them going solar. They where like R1500 each, BARGAIN!!! Not.

+-250 cycles is more or less what the gave during the excessive power failures on UPS'es when the loads where high, and the drained too low.

Really sorry for the bad news. No-one told me when I started. Had to learn it the hard way ... 3 sets later. 

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I guess I should say thanks, but this is really bad news.

I know R1500 is cheap, but x 16 is a lot of dough I just dropped on something that will only last me 8 months!!

I've had them for about 2 weeks now. It's too late to take them back. I even threw away all the boxes.

If you hear about about the murder of a battery rep tomorrow............ it wasn't me!

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9 minutes ago, ace said:

... will only last me 8 months!!

Depends on how you use them ... can last 5 years if used lightly, or 2.5 if used wisely, or 6 months if used very hard.

Like I said, don't dispair, they are good training batteries!!! You don't want a more expensive bank and mess that up. That is far worse.

 

Ps. That hydrometer these batteries have now-a-days ... useless. It is only on one cell. The cells next to it can be dead, battery still shows green.

As such, I have posted pics on this forum somewhere, where they exploded in a UPS. 

And I have burnt my fingers badly, the smell was awful, testing a sealed lead acid battery on a UPS under load. Hydrometer on top showed green, volts where perfect. Inverter struggle with a 350w load. Switched off and as I touched the pos pole to disconnect the lug, it was burning hot. Battery was shorting without any visual indication.

The above can happen to ALL lead acid batteries. Nice thing with batteries that require water is that you are forced to check them regularly, so you use a hydrometer per cell if in doubt.

Today the lithium's are coming in fast and strong, the guys here are using them and really like them.

So don't despair ... make them last by using them lightly after you got a BMV.

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I'll have to make do with what I've got right now. I'll try my best to use them lightly.... as soon as I know what voltage lightly is - Lol!!

Can you recommended a BMV that is reasonably priced that works well. 

I guess if anything, that should tell me how much I have left in the battery.

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Just now, ace said:

Can you recommended a BMV that is reasonably priced that works well. 

Contact https://powerforum-store.co.za/ - Store is re-opening, ask for a good price! :-)

Here, lets kick-start it for you. 

@Energy can you help Ace for a good price on a BMV?

If Energy cannot help, there is another forum member that I can refer you to. First the shop, helps to keep the forum going.

 

Then one last bombshell: Where are you based? You saw the deadline for CoCT registration for solar systems?

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On 2018/09/20 at 8:34 PM, ace said:

I'll try my best to use them lightly

Hi Ace. Please do use them Lightly. I bought one to test, it was secondhand from a bank similar to yours. Guy used them like we use our Trojans, could not keep up with the loads and replaced them after 6 months (If i remember correctly). It ran a while at my place, with everything within spec.. THIS happened after a few months. I mainly kept it full with the occasional discharge. 

I believe a few other also had Royals explode on them.  

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5 minutes ago, ace said:

Any idea what caused that?

Build up on the inside caused an internal short. The spark caused the  Hydrogen to ignite, causing an explosion,  but vent hole to small to release the pressure. Something had to give. 

Edit: Build up is mainly caused by frequent charging. And the deeper you discharge the more you have to charge, increasing the buildup. 

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4 minutes ago, ace said:

Ok, now I suddenly don't care about the battery life but my own life instead!

I am sure that if you use them as recommended, you should be okay, I dont want to scare you, its not my intention, but i feel you have to see the possible outcome if you overuse them.

If you follow TTT's advice, and stick a BMV in the circuit, you will be able to manage your bank safely. 

Edit: I did not worry about a BMV on my secondary system before this incident. You will see in my signature, I have learned my Lesson. Even though the BMV cost more than halve what I paid for the 2 replacement battery's, I will not run a battery without knowing its true state. 

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1 minute ago, Jaco de Jongh said:

I am sure that if you use them as recommended, you should be okay, I dont want to scare you, its not my intention, but i feel you have to see the possible outcome if you overuse them.

If you follow TTT's advice, and stick a BMV in the circuit, you will be able to manage your bank safely. 

It is now my 1st priority.

Thanks for sharing your info.

Any idea of what a safe voltage to discharge to is - until I get a BMV? - Is 49v too low?

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3 minutes ago, ace said:

I'm absolutely shocked at what Im seeing & reading. How can these things still be sold commercially?

Don't stress. It is simple. This goes for all batteries - not sure about lithiums or that fake capacitors batts posted earlier today.

Sealed and not-sealed lead acid batteries ... way to find the problem BEFORE it becomes a problem is to frequently feel each batteries pole for heat ... or sides / top. Pole is easier.

If you feel ANY difference in temp on a batt compared to the others ... take it out.

Obviously must be done under heavier loads, discharging or charging.

Ti does not just go BAM one day ... it builds up and getting worse day after day. By the time they pop ... weeks / months had gone by.

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4 minutes ago, ace said:

Any idea of what a safe voltage to discharge to is - until I get a BMV? - Is 49v too low?

You will soon realize that voltage is not a true indication of the state of the battery. The BMV will show you the true State of Charge in %. And you will then manage your battery's on the SOC and not the voltage. That is why we all recommend the BMV

Sorry, I did not answer the Question. I guess 49 is fine. 

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Hi-Ace ... sorry, I had to ... have to keep earning the Notorious banner see. :-)

I have Trojan T105RE's. Today was the first time EVER they worked this hard ... will tune it. See the watts on the batteries.

Not worried one bit. Water is full, they are equalized once in a while and lightly used generally, very seldom below BMV SOC of 80%. So maybe 8-10 years.
There are days they are not fully charged, if they are charged once a week to 100%, I'm happy. And I feel them temp now and then under load.

Batts can take it, yours too, just keep a "finger" on them. (Pun literally intended.)

image.png.eb70d6376e511f192455ef129f33fc53.png

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13 minutes ago, ace said:

Do I need one for each parallel bank or just one for the one complete bank?

I know this is a lot to take in right now. Please keep this in the back of your mind. I would also recommend Battery Balancers because of the 16 batteries in four strings. And please make sure as finances becomes available to fuse each string separately for extra safety. This will prevent a short between strings if something in one string goes wrong.  I think TTT showcased a nice fuse recently. 

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