adding water - battery performance

abrockca · May 2011

Hi -

I have new batteries - 12 S1380s from Rolls Surrette. One of them arrived dead. We went ahead and hooked them all up anyway.

The first night -Saturday - we only got about 130 amp hours before having to turn on the generator which is bad, but we attribute to the dead battery.

Yesterday, I tested the SG of the batteries after they were in float; most of them were at 1.225 or 1.250 (except, of course, the dead one). This is higher than when they arrived, and I expect it will continue to go up.

Then I added water, which I assume lowers the SG. I had to add a lot of water (they aren't kidding when they say these batteries have a deep reservoir)

Anyway, this morning we lost power around 3:30 a.m. - could not tell amp hours used because we didn't reset the monitor after turning off the generator last night (bad on us) but we should have not used more than 45 or 54 amp hours at that point (we pull less than 9 amps at night; generator was turned off around 10 or so).

Would this decrease in performance from the first night be due to the water that we added?

Any advice is appreciated!

Anne

Cariboocoot · May 2011

Re: adding water - battery performance

Surrette should replace them all or give you your money back. One arrives dead, the other short on electrolyte? That's nuts.

Batteries need to be fully charged before adding water. The very first thing you should do with new batteries is leave the loads off and run them through the full Bulk/Absorb cycle to make sure everything is up to snuff. If the plates are exposed, you should add enough water to cover them before charging.

It is true that it takes a few cycles before batteries reach their full capacity (after which they start dropping) but this whole scenario sounds like bad batteries to begin with.

abrockca · May 2011

Re: adding water - battery performance

They had been charging over the last couple days; so they charged Sunday and Monday, I added water Monday afternoon....

So that shouldn't have caused the drop in capacity? sigh.

mike95490 · May 2011

Re: adding water - battery performance

After you add water, you need to charge, you just diluted the acid, and discharged the battery. I water mine in the AM, and let them charge all day.

abrockca · May 2011

Re: adding water - battery performance

Mike, we'll see how they do after charging today, then. I never had this kind of performance drop after watering my last two sets of batteries. Of course these are new and they took a lot of water.

Anne

mike95490 · May 2011

Re: adding water - battery performance

SG of 1.5 add water now the SG is 1.2 Discharge (or diluted)

so I add water in the AM, and let the chargeing all day stir it up

abrockca · May 2011

Re: adding water - battery performance

Thanks, Mike - makes sense!

Surrette also recommending EQ'ing since the batteries were manufactured last August....

Anne

blackswan555 · May 2011

Re: adding water - battery performance

Remember a string of batteries is only as strong as the weakest one, Your "dead " cell has been damaged an unknown amount, I would recommend going for replacement on at least that one, Maybe the whole lot if they have been left to self discharge for that long,

When you get your new cell I would suggest a good read of the rolls battery manual especially this part

A battery may not be fully charged when received. The fi rst charge brings the battery to an operational state. Before this charging
process, the cell electrolyte level should be checked. Please ensure the electrolyte (liquid) covers the plates. If this isn’t the case, add
distilled water until all the plates are just submerged. It is important not to over fi ll because the level will rise during the charging
process. Charge voltages are indicated in Table 2.
The electrolyte’s specific gravity is the most accurate measurement and it is recommended to verify its value to determine if the
cells are in fact fully charged. The specific gravity should be constant for 3 hours for an accurate full charge reading. Check the state
of charge as related to specifi c gravity. Initial charging may take 10 hours. Once the battery is fully charged, verify the electrolyte level
in the cell once more. The fl uid should be 1/4 - 1/2 inch below the vent tube on each cell as shown in Figure 1. Carefully add distilled
water to adjust the level if needed.

Paying particular attention to this part

The specific gravity should be constant for 3 hours for an accurate full charge reading.

Only when the SG stops rising is it done, they mention it can take 10 hrs, I have had it take more like 20 on something that sounds similar to yours, I like to EQ at the same time, again till SG`s stop rising, top up to the recommended level, Give them another hour to mix added water, The results & SG`s then are the first entry in their service history and a good reference point for the future, (Rolls take about 60 cycles to bed in, SG`s will shift a little, but not much)

Charging, What charge controllers are you using what amps do you "see", what are the absorb voltage and times set to ? Do you have battery temperature sensors for all charge sources ?

Have a good one
Tim

bat manual,http://www.rolls-battery.com/pdf/Rolls%20Battery%20User%20Manual.pdf

abrockca · May 2011

Re: adding water - battery performance

Hi, Tim -

Got worse last night; had to start the generator when we were at 33 amp hours used. Hadn't lost power yet but was close to it.

Yesterday, after getting to float, I ran EQ based on Surrette's comments - did for 2 hours. I've been told in the past not to do it longer than that due to risk of fire. Checked SG on a couple batteries after that; they were close to 1.250. This morning I checked some other batteries and they were around 1.225. That's in the fair range. This was after the generator had been running for 5 hours or so.

Don't know if it's the one bad battery doing it. Haven't gotten an update on when I'll get the replacement - dealer is still waiting for one to get to him. Doubt it will have the same date code, but hopefully that won't matter too much since these batteries are still so new.

Doubt very much that Surrette will replace all 12. They wouldn't replace all my 8 when they started failing after only 18 months. And honestly I really don't want to have to redo the whole project to get 12 new ones in.

Thinking of just letting the power die tonite since propane is so pricey; as long as I power down anything that could be damaged or that will make noise if it loses power, should be good. We don't have much running at night anyway; we were pulling under 8 amps last night.

You know how they always say Surrettes are the "rolls royce" of batteries? beginning to think they're more like one of those sports cars that break down whenever they leave the garage... the more nights I wake up to run the generator the madder I get that we got a dead battery.

Anyway, charge controllers may also be a factor; ours (outback) are doing some odd things. We're planning on replacing them with Xantrex controllers; hope to get the new ones before the weekend.

Yes, that "sucking sound" you hear is the money leaving my bank account this month... yea for income tax refunds, but would rather have spent on something more fun!

Appreciate everyone's comments and sage advice!

Anne

blackswan555 · May 2011

Re: adding water - battery performance

Whats up with the outback charger ? There were a few bad firmware ones, but nothing that can not be fixed ? OB tech support is very good, Give them a ring/mail or post on the OB forums,

Going on you post, I will have a guess that you do not have temp sensing and /or the OB was left at default from new ? Both of these will lead to premature failure, Either one in as short as 18 months

please elaborate on how you last set died ? even a new CC will do about the same if installed the same, I would sort and stick with the OB, It is about one of the best you can buy,

Tim

to add

Yesterday, after getting to float, I ran EQ based on Surrette's comments - did for 2 hours

I do not think you did, :-) EQ is not a timed operation, it is finished when all SG`s stop rising, The batteries MUST be fully charged before commencing to EQ eg the SG`s have stopped rising at their normal charge voltage,

abrockca · May 2011

Re: adding water - battery performance

Um, no, we had temp sensors and did not leave them at OOB settings. We're newbies, but we had good advice from the guy who installed the system with us.

But we changed some settings when we installed the new batteries and the Outbacks don't seem to be recognizing the new numbers, so something's going on.

Don't want to turn this into a thread on our controllers; but briefly -we have two controllers because we installed panels at two different times; we hear the Xantrex ones will network together so it's easier to keep them in sync; they also have better capabilities to link to our PCs so we can track data better; and they have a better (more info) unit that displays in the house. To get the updated Outback display unit we'd have to do some rewiring, so we just have the basic one that shows volts, amps and amp hours used.

Our last set of batteries started failing after 18 months; we replaced over time four that had low SGs, still had problems; then we did a capacity test on the 4 that always showed good SGs, and they failed miserably. (should have done that months earlier I guess!)

Surrette says we overcharged; I'll agree toward the end we had pushed the settings pretty high but that was just to try to reclaim them. Anyway, we're still battling with Surrette over that.

Appreciate your thoughts! But we are going to replace them...

Anne

abrockca · May 2011

Re: adding water - battery performance

oh - re EQ time - we use the Outback controllers and they definitely have a stop time - you set how long you're doing EQ for. We started it after our batteries were in float. It may be 2 hours wasn't long enough; but we don't want to overheat. Even Surrette's manual says that wet batteries must be delivered to the end user fully charged - in our case, they weren't and there was a dead one, so I'm not too happy this week....

Anne

Cariboocoot · May 2011

Re: adding water - battery performance

Anne;

Replace them is right. Replace them with Trojans if you can.

FYI, OB controllers can network easily via the OB 'Hub'. If you have an OB inverter it too will connect up with its MATE, and Tall Girl here sells some very interesting monitoring software for OB systems (check her profile for link). On the whole, the Outback systems networks better than Xantrex from what I've heard about them. MX & FM controllers can be daunting in their complexity. But I really don't think that's the problem here. You were sold bad batteries. Get angry about it! :grr

Surrette is off my list of recommended equipment. There have been too many instances of late.

blackswan555 · May 2011

Re: adding water - battery performance

re EQ time - we use the Outback controllers and they definitely have a stop time - you set how long you're doing EQ for. We started it after our batteries were in float

The problem is, EQ is not a timed operation, And as mentioned before,They HAVE to be fully charged before you start, just because the OB ( or any other controller not using advanced battery sensing) go`s into float is not an indication the batteries are charged, SG stopping rising is what you need to be looking at,

Tim
ps, what are you absorb time and voltage setting`s ?, how did you arrive at them ?

we replaced over time four that had low SGs, still had problems;

The main reason for low SG is undercharging, Which I suspect you have been and still are,

Photowhit · May 2011

Re: adding water - battery performance

There are both a timed Equalizing and a methodic Equalizing checking the SG of the cells until they quit rising, I think this methodic checking would be considered a more proper method or a more "true Equalizing" and the monthly or bimonthly timed equalizing a mainenance equalizing.

I thought I had suggested following Rolls advice on this during the previous thread, as a warranty is involved, but don't see this, I would speak with them about the equalizing. With this big a difference (did the SG 1 battery come up?) it would take a good bit of time. You would need to monitor the SG of each cell and the temperature of the battery bank. I suspect a large imbalance like this would actually degrade the other batteries bringing the single battery up.

If your only using 54 amps on the battery side (24 volts) you might be able to get by with the single set for a couple days. I'm not sure what your running, but if you can load shift, turn off out side lights for a couple days, you might not even run below 80%.

abrockca · May 2011

Re: adding water - battery performance

Hi, Tim - you think we're undercharging and Surrette thinks we're overcharging! My head hurts! some days I want to just pay the oodles and gobs of money it would take to get on the grid...<grin>

You're right, of course, time is a crude measurement for EQing... just an easy one! Good idea to see if the SGs are still rising or not before starting...

Our settings now pretty much match the manual - 28.8 for absorb, 26.6 for float; 3 hour absorb time.

Cariboocoot, we wanted to set up a 12 battery system with 2 volt batteries; I hear Trojan batteries in this style still have three cells in them while Surrettes have just one cell, which makes adding water easier. I may have to start kicking myself over the decision though. Our first set of batteries were Trojans; I treated them horribly and they lasted almost four years; I babied the Surrettes and they died at 18 months...

WANTED: Batteries that take a licking and keep on ticking<grin>

Anne

Photowhit · May 2011

Re: adding water - battery performance

abrockca wrote: »

WANTED: Batteries that take a licking and keep on ticking<grin>

You might want to look into a forklift/traction battery.

All batteries are made up of 2 volt cells, Trojan cells 2 volt individual cell batteries, and mirrors Rolls Surette on many.

The advantage of a forklift is that all the interconnects are done. NAWS has reports of them lasting 20 years and we recently had someone report that here, though perhaps not the best setup (1500 AmpHour 12 volt!)

NAWS sells them, and I'd be glad to PM you a link if NAWS's sizes don't fit your needs.

BB. · May 2011

Re: adding water - battery performance

Do you have a way of measuring current (DC Clamp current meter) on each string during charging/discharging?

In the end, measuring specific gravity with a good hydrometer and temperature correction (if needed) is the gold standard (which you are doing).

Measuring voltage across each battery/cell during charging/discharging can show issues/weaknesses pretty quickly. Look for any cells that have high voltage or low voltages during charging/discharging (there will be some variation--Looking for large differences--for example one battery with much higher voltage during charging or one cell with much lower voltage during discharging). All it take is one bad cell in series to "kill" the performance of the entire battery string. Obviously, not good for new or 18 month old batteries.

Also looking to make sure that you measure voltage drop (when charging or discharging "higher" current) across each cable/connection so that there are no poor connections between the cells.

1050 amp Hrs. @20 Hr. rate 2 volt cells... 12 of them. Is this a 12 volt or 24 volt bank (thought it was 12 volt--getting lost).

What is your typically rate of charge (solar, genset). What are your solar (watts) and genset AC charger (amp) ratings?

I am stumped--I am sure you are seeing what you are seeing--but something is happening somewhere.

Something is wrong--huge cells and very light loads on your part. Overall OK specific gravity readings (dead cell withstanding).

When your bank voltage falls, do all cells fall equally or is there just one or two cells are are dropping a lot?

-Bill

blackswan555 · May 2011

Re: adding water - battery performance

WANTED: Batteries that take a licking and keep on ticking<grin>

You have them lol, The problem I have found with big Rolls is they need a good hard kicking sometimes (Good hard discharge) and they like a lot of charge, you mention of only seeing 1.250 as a "high" which seems low to me, I would expect more 1.270 ish, So you need to keep charging till sg`s stop rising before even trying a "proper" EQ 2 ways to do that, with gen, or below

28.8 for absorb, 26.6 for float; 3 hour absorb time.

I would go, 29v and all day on absorb, keep a close eye on water levels, your SG`s should come up gently and you will need to EQ less, If water usage is excessive back voltage down a notch,

Tim

abrockca · May 2011

Re: adding water - battery performance

Photowhit, I just spent $4600 on batteries, so can't switch to forklift style now...bummer. I'm hoping next time we get batteries that lithium batteries are ready for prime time for off grid applications; we'll see. Otherwise, I'll hunt down the NAWS and check them out!

BB, haven't checked all the cells out after a failure; good idea to do that, see what they're saying. Could be it's the one bad battery causing all the problems - I certainly hope so; they say we'll have our replacement on Friday.

Thinking I shouldn't do any long EQs until the replacement is in the string, or I might have to do it again when it shows up. Does that make any sense?

They're all one bank, so can't cut out half of them. Thought about cutting out the bad one and having 11 run - but that takes setting changes and if the new one is here friday, probably worth the pain for now.

Rolls said to EQ, didn't say how long; today they haven't commented on the results I emailed them. They just said the new one is coming friday, nothing on the rest of the email yet. Earlier when I asked them settings, they said follow the manual and then quoted settings pretty much like what we're using.

blackswan, agree over time we want to see 1.265 or 1.275, but they are higher than they were when first installed, so we're heading in the right direction!

Anne

Photowhit · May 2011

Re: adding water - battery performance

abrockca wrote: »

They're all one bank, so can't cut out half of them. Thought about cutting out the bad one and having 11 run - but that takes setting changes and if the new one is here friday, probably worth the pain for now.

OK I'm confused too, thought there was 8 batteries, I understood 24 volt, did you add 8 to old?

If you have a 24 volt bank, made up of 3 strings of 4 batteries, each string should have a fuse or breaker, and likely a disconnect where the bank ties into the system. Switch off the disconnect, then flip the breaker(or pull the fuse) to the string with the bad battery. Now you have a bank with all good batteries (hopefully) and a third smaller size. Is your over night load 54 Amps (I think you stated) on the battery side 24volts? or 54 amps at 120 volts?

Your shutting down your whole system when you do this, might be best to shut off the charge controllers and your inverter first, or what until night time, Not sure what size your array is, but a full charge disconnect might be hard on the breakers, even though they are made to handle it. Sorry I didn't add this to original post.

Do you have a meter or does your charge controller tell you how many Amps have headed your battery banks's way? I think you still have a bad battery/cell and that is bringing down the bank as a whole, cut out the bad one and your bank should still handle the load, with out cutting out in the middle of the night.

Forgot, NAWS is our sponsor, Norther Arizona Wind and Sun

BB. · May 2011

Re: adding water - battery performance

I believe these are 2 volt cells... 12x 2v = 24v

Remember, that even though you are looking at 23-29 volts for charging--Each cell is looking for exactly 1/12th of that (charging and discharging).

You will have some variation, especially as the cells approach 100% state of charge (some cells are at 100% charge and high voltage/gassing, and others may be at 90% charge--using the common series current to bring them up to 100% to (equalization).

Also, what is the current you are pumping through the the battery bank during charging--5-13% of the 20 Hour rating is a good starting point for discharged cells... 5% is a common suggested current for "equalization".

If the cells are not full, and the current is tapering off during charging--it would sound like one or two cells are dropping the most voltage (unbalanced cells -- 30% and 100% charged) or you have an open cell (not carrying it share of the load/current).

You have 12 (hopefully nearly) identical cells. One or two cells that behave differently from the rest are bad news.

And--It sounds like you only have 12 cells--including the "dead" cell still in the string? If that is the case--then that one cell could certainly be the cause of your current charge/discharge problem.

-Bill

Photowhit · May 2011

Re: adding water - battery performance

Thats right she was saying something about single cells, sorry all, I gotta get more sleep!

abrockca · May 2011

Re: adding water - battery performance

glad Bill was able to clear things up! (had to actually work for a few hours, darn these day jobs)

I used to have 8 3-cell batteries - first Trojans, then Surrettes. Those were hooked up as two banks.

But the new batteries - 12 of them, 2 volts - are hooked as a single string.

Sorry about the confusion I sometimes type too fast and don't think before I type!

Hoping/assuming it's the "one bad apple" - that is, one bad battery - that's causing me my grief right now. Still don't know why I was able to get 130 hours the first night but not since then, but guess it's all part of the fun and joy of batteries... stuff fluctuates...

Anne

adding water - battery performance

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