Battery Question

rake1 · October 2013

As some of you may remember I bought two Surrette s-530 400ah 6 volt batteries connected in series for my camp. Well I have had these about a year now equalized them at about 5 months old all was great. I equalized on the weekend (now 10 months old) and all may not be great now. I have 5 cells at 12.65 and maybe even touching 12.7 reading with my Hydrometer. But one cell is reading 12.45 do I have a bad cell? I equalized for two hours and that cell was still down so I did it again for two more hours. At the end of the day I did see some improvement from 12.35 to 12.45. This is using my C35 charge controller which will on equalize for 2 hours at a time but I can restart it as soon as it stops. It was putting in 16 to 16.3 volts during equalization and the cells were boiling good. The one cell I speak about wasn't boiling quite as much. Any thoughts?

Blackcherry04 · October 2013

Re: Battery Question

rake1 wrote: »

As some of you may remember I bought two Surrette s-530 400ah 6 volt batteries connected in series for my camp. Well I have had these about a year now equalized them at about 5 months old all was great. I equalized on the weekend (now 10 months old) and all may not be great now. I have 5 cells at 12.65 and maybe even touching 12.7 reading with my Hydrometer. But one cell is reading 12.45 do I have a bad cell? I equalized for two hours and that cell was still down so I did it again for two more hours. At the end of the day I did see some improvement from 12.35 to 12.45. This is using my C35 charge controller which will on equalize for 2 hours at a time but I can restart it as soon as it stops. It was putting in 16 to 16.3 volts during equalization and the cells were boiling good. The one cell I speak about wasn't boiling quite as much. Any thoughts?

I guess you know the answer, keep on hammering them until you get that cell up with the rest. If you don't it will only get worse over time. Keep a eye on the Temperatures ( 115-120 max ). Check the SG on that cell every hour, as long as it's rising, you making headway. It's always going to be debatable on the effect on the other cells, but you'll lose the whole battery if you don't. It will open the pores in the lead and they will all perform better.

rake1 · October 2013

Re: Battery Question

Thanks so you are saying just keep equalizing until it comes back? ANY THOUGHTS AS TO WHAT WOULD CAUSE ONE CELL TO GO BAD?

Blackcherry04 · October 2013

Re: Battery Question

rake1 wrote: »

Thanks so you are saying just keep equalizing until it comes back? ANY THOUGHTS AS TO WHAT WOULD CAUSE ONE CELL TO GO BAD?

It's hard to tell why one ends up being lower. It's happened over time, it probably has a different resistance that the others. Your only choice is to keep on equalizing it. If you want to start a warranty service ticket, that you can do. Right now it's probably within their acceptable range. Do it for another hour and see if it rises. They recommend to go for 2-3 hours after you stop getting a rise.

http://rollsbattery.com/public/docs/user_manual/Rolls_Battery_Manual.pdf

I just had 6 , 2 V delivered today, I guarantee you they will be all over the place on the SG's and they were shipped straight from NS last week.

Vic · October 2013

Re: Battery Question

rake1 wrote: »

Thanks so you are saying just keep equalizing until it comes back? ANY THOUGHTS AS TO WHAT WOULD CAUSE ONE CELL TO GO BAD?

Hi rake1,
As Bc04 mentioned, this cell is probably not yet bad, but would head more in that direction without EQing and perhaps more attention.
Yes keep at the EQ. And, in my opinion the EQ voltage should be temperature compensated. Most CCs do not tem[ comp the EQ voltage, so this would have to be done manually by you.

The EQ voltage you are using is on the high end of the recommended range, it the battery temperatures are at about 25 C nominal. If the batteries are cool, this voltage is probably within range.

Seems to me that you should EQ this battery bank more often. And, as you probably know, there is a temperature compensation needed for your Hydrometer, unless it automatically compensates (as a few do). As the battery electrolyte temperature increases (during EQ for example), the SG reading on most Hydrometers is a bit on the low side, often making things look worse than they are when you are trying to bring up the SG on a few cells, which requires a long EQ time.

Your solar input is a bit on the small side, using rules of thumb. But believe as a weekend camp you can often catch up during the week. And the turbine might add some charge current if you have good winds. Believe that this has been mentioned before. Good Luck. The Surrette banks here are in their ninth year ... knock on lead. Vic

BB. · October 2013

Re: Battery Question

Just to ask--You are using clean distilled water to refill the cells? No contamination in the electrolyte? Do not overfill/boil out electrolyte?

-Bill

rake1 · October 2013

Re: Battery Question

My c-35 is temp compensated but do not know if that side of it works during EQ. The temp in the camp is good these days say 20C so I have to assume the electrolyte is close to that temp. I do not have a temp gauge to keep track of battery temp but I feel no temp difference (with my hand on the side of Battery) during the whole EQ process. You would think I could feel some temp change from 20 to 50 degrees wouldn't you. Remember these bats are large and would have a lot of fluid in them hence the temp change should be slower. My panels are smaller than they should be but I charge with my gen before leaving the camp to full charge so I do believe the bats are being charged up fully.I will keep the EQ up next trip back.
But Vic I do have another unrelated question
How can I tell if I have a bad solar panel?? I look at mine and I see a couple of the cells look like they have a blue tint to them. The panels are only 2 years old at the most, but use to put out as high as 18amps on a good day, now I get 15 at the most.

rake1 · October 2013

Re: Battery Question

Great info thanks I did contact Surrette just to see what they say will keep you posted.

Vic · October 2013

Re: Battery Question

OK, thanks rake1,

The temp compensation value for electrolyte temp change is fairly small, and often can be ignored, but just see NS as your location, so thought would throw that in as a thought.

The EQs that we do here are not long in duration, and to at excessive EQ voltages, so we never see more than 3-4 degree C temp rise above the 20 - 28 C normal summer temps. If one MUST do a Corrective EQ, which can be very long (sometimes over several days, with rests in between), then, the extreme temp rise mentioned by BC might be seen.

Am familiar with S530s. The "C" bank at the main site runs these batts.

Good that you have a generator, and Surrette gives very good support of their customers, so good that you have contacted them

Somehow, I had previously read that you had a, as in one 260 watt PV, so the comment about being a bit light on PV was due to that.

Using a Clamp-On DC ammeter is a good way to determine If each "string" in a PV array is doing its job. Also, if you use a combiner, and it is handy, switching off each string during the Bulk stage will allow you to see the individual contribution from each string.

EDIT: Regarding some slight discoloration, have seen that on some Shell 175 Mono PVs which have been in service 8 - 9 years. So far, this has not affected performance (as far as I can see).

Good Luck, Vic

rake1 · October 2013

Re: Battery Question

I have two panels that add up to 260 watts that is light by about 150 to 200 watts. But I do use my gen for two hours while I am packing for home that gets me through the bulk and into absorb. My charger only puts out 25 amp so I wait for the sun to come out before I start charging (when I can).400ah batteries= 10% 40 amp max. Sun 10 to 15 amp gen 25 amp so I am right at the 10% need for proper charging. Sun will easily finish up the rest of the charge while I am away. Always at 100% when I come back to the camp. That is way I was a little concerned with the bad cell because I knew I wasn't deficit charging these Batts.No combiner but I could easily through a blanket over one panel and it should do the same job for me.
thanks for the idea

rake1 · October 2013

Re: Battery Question

Have talked to Surrette they are giving me the impression that my controller is not staying in absorb long enough C-35 stays there for 1 hour then floats. If I turn up the float to say 13.6 will this help my situation? I cannot change the absorb time and I am at the max 15v for bulk (as per Surrettes web site)
Do I need a different controller(again) one that will have more adjustment? If so what should I look at?
Just concerned that if I turn up the float will I damage the batts holding it that high.

BB. · October 2013

Re: Battery Question

Apparently some of the models of Surrette batteries really do need >15.0 volt absorb. And they seem to take the higher absorb voltages just fine.

However, you will have to look at your AC inverter (and any direct connected 12 VDC loads). Many (most?) AC inverters do not like voltages >15.0 volts and will shut down (yes, it is a pain).

Is the C35 (or C40) controller set up in dump mode to control charging from the wind turbine? If so, perhaps you can disconnect the wind turbine when you go and set the MorningStar TS-60 to a higher charging voltage when you are gone (and when you are there monitoring the system)?

Another option would be to rewire the TS-60 PWM controller (if PWM) as the diversion controller. And use a PC to reprogram the dump voltage to 15.5 volts (or what ever setting you need). It is less than ideal to wire the solar panels directly to the battery bank and use a diversion controller--But it should do what you want for now without the cost of a new controller (assuming you have Vmp~17.5 volt panels and a PWM TS-60 controller).

You may have to call MorningStar to confirm you can use a a PC to reprogram the controller to 15.5 volt absorb in diversion mode... I could not find anything in the manual on setting limits for the PC interface with a quick read through/search.

-Bill

rake1 · October 2013

Re: Battery Question

great information thank you I have reprogrammed the TS 60 in the past to
> dump at 15.1 which I thought was a good voltage.the C 35 is used for the
> solar panel only and is not in the diversion mode.I normally shut the TS 60
> offso it doesn't dump when I am trying to put a little extra into the
> batteries. what if I charge the batteries as normal and once they went into
> float I just equalize for let's say one more hour after that at aboat 15.1or
> so that should give me more absorb time correct.I realize like you with told
> me earlier this is only a bandaid solutions but should do the job for me
> while I am at the camp.please correct me if I'm wrong. Ps charge controller
> would you recommend I buy that has a little more absorb time built into it
> then my C 35 or has an adjustable absorb time?thanks for the help
>

This is my last reply from Surrette am I reading this correct? They are telling me I can charge these 400AH Batts at 30% or 120 amps.

That C35 is okay for day to day charging, but It just doesn’t have enough power behind it to fully charge those batteries.
You can charge a FLA battery to up 30% of the C20 Rate. 10-20% is the usual minimum to keep the absorb times as short as possible.
Do you have any other sources of charging? I ask because with the change of batteries over the last 20 years and the C35 it’s just not going to get the charge done properly.
It would do well in keeping the batteries near a full charge but it will never be able to fully top off a battery.
The Charge voltage on our website only says to charge at 15 volts if your temperature is between 0C and 16 C

What I would do is use the C35 at the top end of the scale for temp (Cold Temps) and then once a week or at least every couple of weeks use your inverter in which I hope is programmable to properly charge the battery. If the inverter is like the old DR, you are going to have to do EQ1 or EQ2 charges to get the SG to where it should be every two weeks

Cariboocoot · October 2013

Re: Battery Question

You could put 120 Amps to 400 Amp hour batteries without inducing thermal runaway. But I wouldn't recommend it as a daily charge routine.

But you should have 40 Amps available for charging, which a C35 is not capable of delivering.

One of the biggest problems with Surrettes is their desire for higher-than-typical charging Voltages. I guess that goes along with their higher-than-typical prices.

If you measure the current going to the batteries during Absorb you can get a good idea of whether or not they're getting enough time in that charge stage. If they drop down around 8 Amps (to the battery, not just from the charger) before Absorb is over that should suffice.

Some Surrette owners have found it necessary to have regular EQ cycles (weekly, monthly) to keep them at proper charge levels.

Blackcherry04 · October 2013

Re: Battery Question

Having used a " Fast Charge " scheme 3 years there two things I have learned. Using 25-30 % is fine in bulk as long as the AMP HRS you are returning is more than the Charging amps. When I hit gassing ( 14.2-14.3 @ 12V ) I like to cut the current in half and drop one charging source. If you use too many amps it's just a over voltage that will trigger a quick Absorb. If the over voltage is more than .2-.3 above the actual battery voltage it really messes your absorb up and a true full charge. Your much better off with a longer slower absorb. How do I know this ?? If you push large amounts of current and finish a absorb to float the SG's will be low, you can re-bulk @ 15 % and it will take a long time in absorb to drop to 2% ending amps because the batteries are absorbing the current at a much lower rate. You can then re-bulk again and it will run through all the stages to float in a very short time because the batteries are at 100 % and the SG's will be high. To me that indicates a much better charge.
.

rake1 · October 2013

Re: Battery Question

Who on this form has a camp in the wood with solar and the ability to put out the kind of amps Surrette is talking about? Man you would need a pile of solar panels, for a weekend retreat that is out of the question. with all the advice I have gotten here the only real solution I can come up with is keep charging with my 35 amps and EQ monthly. Or maybe EQ for an hour at a lower rate just at the end of the absorb stage do you think this would work. My Gen is only 1000 watts (8amps AC) but will run my 25 amp charger but I believe it is at its limit. So even if I got a bigger charger I don't believe my gen would run it. So I am back to my last suggestion. Am I right in saying that gen could run up to 83 amps DC? Problem is I would be looking for a new gen if I ran it like that each weekend

Cariboocoot · October 2013

Re: Battery Question

Agreed. To put out the kind of current Surrette is talking about you'd need like a 2kW array. That's pretty big for an occasional use off-grid cabin! You should be able to meet the 10% rule-of-thumb with about 1/3 that much panel, but you would need a higher capacity controller than a C35.

Your 1 kW gen would probably manage a bit less than 83 Amps what with the efficiency losses and all. Perhaps 70 Amps. But it should be able to manage a 45 Amp Iota. Remember that the current draw will not necessarily be as high as the charger can put out, nor will it stay high. But I don't think the Iota can be set for Surrette's preferred high Voltage charging.

Blackcherry04 · October 2013

Re: Battery Question

Rake, you don't need to get to excited, There 3 things that control a battery charging . Voltage, Time and Current. In your case you need to return what you consume and a start into the absorb because you cannot get more than a hour of absorb with the c35. By using Time you can start early on sunday and put back the amps you need so then the solar can finish the charge during the week. I have no clue what your wind contributes to charging plan.

Doing a EQ for you is just a extension of the absorb, your already using EQ voltage. Your SG's are going to tell you where you need to go. Just adjust your scheme that will get you there. At this point you only have one cell that is lagging and it's not that bad.

Wouldn't a Morningstar SunSaver MPPT 15 amp handle those panels ?? MS view would be perfect for you. What charger do you have ??

Vic · October 2013

Re: Battery Question

Hi rake1,

First, believe that the latest from Surrette indicates that they believe that 15-ish volts for Absorb is on the high side -- only when batteries are between 0 - 16 C. None of the Surrette battery banks in service here, or at any of the neighbors (that I know who run Surrettes) require anything above 58.2 or so with good solar conditions. Winter Vabs may be a bit higher due to short days. The perfect EA value on these Surrettes with the 58.2 Vabs nominal (temperature compensated) is 1.0% of real 20 Hr Capacity, measured on a Shunt, so it is actual battery charge current, FWIW.

Believe that the comment about 30% of C20 as a good charge rate probably comes from cycling the batteries to about 50% SOC. In this situation, to fully recharge the battery in one day, the Bulk and early Absorb needs to be at ah high current to get the job done, when using solar power in particular. Believe that you do not take your batteries down to 50% while you are there.

However, it is good to cycle FLA batteries. Taking them to 50% SOC on occasion is good for their health. Given your limited solar and generator charge ability could mean that these deeper cycles seldom occur, because it seems so tedious to do the recharge. So stepping up the PV power, and perhaps a somewhat larger genset and charger or Inverter/Charger could be a good addition, when the funds are available.

We EQ our Surrettes about every 3-4 months (only as needed), to continue the pedantics.

MPPT CCs have spoiled me, as they often have comprehensive LCD displays built in, and allow setting voltages to 0.1 V resolution and times like EQ and Absorb can be set to the minute.. This can make knowing what is going on (and has happened in the past) easy to see, and remedies easy to control. Opinions based on the Surrettes here, including some S-530s. YMMV, Vic

rake1 · October 2013

Re: Battery Question

Blackcherry04 This is exactly what I am doing now. Every Sunday charge with gen and sun at usually 35 amps if I have good sun at least until the c35 goes into Absorb. The automatic Battery charger that is putting out 25amp reduces current and shuts off before I hit full Absorb as it thinks the Batts are full. So the rest of absorb is left to the sun and usually has no problem finishing the absorb and goes into float before I leave. Keeping in mind that is at a setting of 15V bulk and about 14.4 absorb for 1 hour. I have gotton my hands on a manual battery charger that puts out 10 amps and doesn't shut of like my smart charger I have now.This may come in handy to get another hour of absorb time at the end of the charge just as it hits float.

Blackcherry04 · October 2013

Re: Battery Question

rake1 wrote: »

Blackcherry04 This is exactly what I am doing now. Every Sunday charge with gen and sun at usually 35 amps if I have good sun at least until the c35 goes into Absorb. The automatic Battery charger that is putting out 25amp reduces current and shuts off before I hit full Absorb as it thinks the Batts are full. So the rest of absorb is left to the sun and usually has no problem finishing the absorb and goes into float before I leave. Keeping in mind that is at a setting of 15V bulk and about 14.4 absorb for 1 hour. I have gotton my hands on a manual battery charger that puts out 10 amps and doesn't shut of like my smart charger I have now.This may come in handy to get another hour of absorb time at the end of the charge just as it hits float.

I think your generator will run a IOTA dls-45. That would give you a much better charging rate. If I was going to buy one ( $150 ) I'd get it with the plug in IQ-4 module. That would give much more flexibility, as you can run it manually and then plug in the module for automatic. I can tell you how to adjust the output voltage so it will give enough Voltage for your Surrettes. The max voltage is about 15.5 on them. I have run the same routine on my boat for many years as you do, it just takes a little planning.

You'll have to wade through the garbage on some of these posts.

https://www.google.com/search?q=honda+eu1000i&ie=utf-8&oe=utf-8&aq=t&rls=org.mozilla:en-US:official&client=firefox-a#psj=1&q=honda+eu1000i+45+amp+IOTA&rls=org.mozilla:en-US%3Aofficial

rake1 · October 2013

Re: Battery Question

Vic you are right I have never seen my Batts below 12.3 maybe touch 12.2v when real cold which indicates they are still 70% charged. But what I have noticed is on my trimetric display is when entering camp it reads 100% usually about 14.2V or higher on the display. 10 minutes after I turn on my TV and lights it is down to 12.4V and holds that for about 5 hours drawing about 12 amps. It may drop to 12.3v before bed time and if I don't charge and no sun the following day by the end of the second day it may hit 12.2v. But that is probably at least 10 hours of min 10 amps coming out of them. And a few hours of no Tv but still 6 amps for another roughly 6 hours and still at 12.2v. I should say i have seen 12.1v on the meter after a weekend of late nights and no sun. The drop in 10 minutes to 12.4 always had me concerned, is this telling me that I am not fully charged to start with? They were like this from new, I actually brought back my first set for replacement after the first weekend at the camp because they dropped to 12.4 so quickly.

Blackcherry04 · October 2013

Re: Battery Question

12.6-12.7 is a theoretical Voltage on a standing Battery. Between the difference in meters, Cells, Inverter overhead and any draw seeing 12.4 V is no big deal. You'll also find that as you discharge it doesn't seem to always be completely linear to the voltage changes you see. You'll also see the Dip and Recovery ( Coup de foret ) in your battery voltage as your loads change. Use your SG's as your guide to the health of your batteries.

rake1 · October 2013

Re: Battery Question

Blackcherry04 wrote: »

I think your generator will run a IOTA dls-45. That would give you a much better charging rate. If I was going to buy one ( $150 ) I'd get it with the plug in IQ-4 module. That would give much more flexibility, as you can run it manually and then plug in the module for automatic. I can tell you how to adjust the output voltage so it will give enough Voltage for your Surrettes. The max voltage is about 15.5 on them. I have run the same routine on my boat for many years as you do, it just takes a little planning.

You'll have to wade through the garbage on some of these posts.

https://www.google.com/search?q=honda+eu1000i&ie=utf-8&oe=utf-8&aq=t&rls=org.mozilla:en-US:official&client=firefox-a#psj=1&q=honda+eu1000i+45+amp+IOTA&rls=org.mozilla:en-US%3Aofficial

Is this what you fellows are suggesting http://www.solar-electric.com/dls-45.html $122.00 and the IQ4 for $15.00? You feel that would have the adjust ability that I would need
Does this also put out AC current? I see this in the specs Maximum AC Current @ 108VAC 11 Amps

jcheil · October 2013

Re: Battery Question

rake1 wrote: »

Does this also put out AC current? I see this in the specs Maximum AC Current @ 108VAC 11 Amps

No, that is how much it will draw (at maximum) from the generator.

rake1 · October 2013

Re: Battery Question

That is what I was afraid of my gen only puts out 8 amps ac.

jcheil wrote: »

No, that is how much it will draw (at maximum) from the generator.

rake1 · October 2013

Re: Battery Question

Guys I guess I am back to square one on this one, I emailed Iota because I saw the 11amp draw on the spec sheet and they confirmed that the DSL-45 indeed will draw 11 amps so my gen is to small to run it. See email below.Story of my life to small again LOL I am going to try the manual charger I have and see what happens.
I would like to thank all who helped out on this I learned a ton again.

Yes it will draw 11 amps . you would need to drop down to our DLS-30 if you intend to use it with your generator.
Thank You,
John W. Kehm

Blackcherry04 · October 2013

Re: Battery Question

rake1 wrote: »

Guys I guess I am back to square one on this one, I emailed Iota because I saw the 11amp draw on the spec sheet and they confirmed that the DSL-45 indeed will draw 11 amps so my gen is to small to run it. See email below.Story of my life to small again LOL I am going to try the manual charger I have and see what happens.
I would like to thank all who helped out on this I learned a ton again.

Yes it will draw 11 amps . you would need to drop down to our DLS-30 if you intend to use it with your generator.
Thank You,
John W. Kehm

One thats 11 amps @ 108 volts, I'd hope that your Generator puts out more than that. I saw to many posts on the sites I Googled to believe it wouldn't, but a 30 would work. I use a 75 amp that many on here said a Honda EU 2000 would never pull, but in use it's only 8.5 amps, it's listed as 17 amps. It's the initial surge as it charges it caps, it won't pull 4-5 amps when it's running.

Cariboocoot · October 2013

Re: Battery Question

People get too easily confused about the difference between the maximum DC output current and the maximum AC input current.

You can use the 'basic' math to tell if you're in the ballpark for a given charger/generator combination.
The chargers are (usually) rated in DC output Amps. So a 45 Amp 12 Volt charger draws approximately 5 Amps 120 VAC in when running at maximum output. That's 600 Watts, and even with power factor and wiring losses will still run off a 1kW generator without difficulty. And remember that the power demand will go down as the battery charges.

jcheil · October 2013

Re: Battery Question

Blackcherry04 wrote: »

One thats 11 amps @ 108 volts, I'd hope that your Generator puts out more than that. I saw to many posts on the sites I Googled to believe it wouldn't. I use a 75 amp that many on here said a Honda EU 2000 would never pull. It's the initial surge as it charges it caps, it won't pull 5-6 amps when it's running.

But remember the Iota (which also I have) is not power factor corrected so (especially) the inrush current will appear to the generator as being more than 11 amps (momentarially). I had a DLS55 when my system was 12v and on my generic 1400/1800w generator would just barely start it, especially when the batteries were low and it needed to put out maximum charging current. Yes, after the initial inrush, it settled down quite a bit, but getting over that first hump is the problem if it pops the generator breaker or stalls it. Again, based on the quality of the generator, wiring, etc; YMMV.

Added: I see what Cariboocoot wrote while I was typing this and I wonder if somehow the design or efficency of the charger has to do with the amount of load it puts on the generator. Because I also had a powermax45 which drew MORE power than the Iota DLS55.

I would be interesting in finding out for my own educational value.

Cariboocoot · October 2013

Re: Battery Question

Well it's certainly true that a battery charger can be designed in different ways and that one may use less power than another for the same amount of current out at a given Voltage. They will all use some power for themselves, both for powering their components and loss to heat. Keeping that power use to a minimum is what makes for an efficient charger. This usually means using heavier-duty components for switching, and that inevitably means a more costly unit.

But on the whole I have never seen a stand-alone charger that is actually suited to RE applications. They tend to lack the ability to be programmed for just the right Voltage set points and current limits, etc. This is why people toy with the notion of rectifying the AC from the gen and feeding it to a Classic 200, although i have not yet heard of anyone achieving this. Bit difficult getting the AC cleaned up enough for the controller.

Battery Question

Comments

Categories