4 New Rolls L16-HC batteries and new Sun Gold Power 12v inverter. Hooked up by our solar contractor on the 19th Dec and we were happy as this should have given us increased capacity over the Duracell 6v system we inherited with the off grid house here in Baja. Problem is that my assumption was that we were good to go and I didn't pay enough attention to any parameters until Xmas eve. Voltage was 11.7v at bedtime and 12.0 on Xmas when we stopped using most of the appliances. Called contractor on 26th and he responded. We have been supplementing the PVs with a generator and external charger. We have the bedtime voltage up to 12.7 (12.4 at 0545 this morning) with multihour generator runs (4 hours on Sat and 3 hours last night) but the SG is still low (1.16-175) right before the sun came up this morning (and yesterday morning). We are not running anything that has a huge draw at night (6-8 amp washing machine during daylight). So I guess my question is are these batteries toast or have a diminished lifetime. Contractor on his way over to add 2 panels today for close to a 40amp input. Thanks
SG low on new batteries
- Thread starter spinoeca
- Start date
Steve_S
Offgrid Cabineer, N.E. Ontario, Canada
The Rolls batteries are a lot tougher than many realize... believe it or not, they can take a LOT of abuse ! Rolls learned their lessons making batteries for submarines. As long as they do not sit for long at empty your ok OR get frozen (not in Baja eh).
You get 12V/428AH useable, assuming 2X 6v for 12V per string x 2 strings in parallel.
Usable is to a MAX of 50% DOD (Depth of Discharge).
PLEASE read this link... Best summary with KISS applied.
Lead-Acid Battery Care - Solacity Inc.
You get 12V/428AH useable, assuming 2X 6v for 12V per string x 2 strings in parallel.
Usable is to a MAX of 50% DOD (Depth of Discharge).
PLEASE read this link... Best summary with KISS applied.
Lead-Acid Battery Care - Solacity Inc.
Thanks Rob
I will continue to monitor SG and voltages after the batteries rest at night and start a logbook for those values. Would it behoove me to have the generator wired directly into the inverter as opposed to going through a battery charger. The latter approach does not give the inverter the chance to monitor the input but as long as the assumption that we are at suboptimal SG is correct then maybe using the charger is the quicker road to full charge. I do not know the size of the battery charger. My contractor says this is easy to do given the inverter.
I will continue to monitor SG and voltages after the batteries rest at night and start a logbook for those values. Would it behoove me to have the generator wired directly into the inverter as opposed to going through a battery charger. The latter approach does not give the inverter the chance to monitor the input but as long as the assumption that we are at suboptimal SG is correct then maybe using the charger is the quicker road to full charge. I do not know the size of the battery charger. My contractor says this is easy to do given the inverter.
We thought we were golden today when the Xantrex C40 charge controller told us that our battery was full (green LED on) and we watched the green LED go through from 1 blink up to 5 blinks fairly rapidly. SG still down though and after sunset the SOC is only 12.4 with no serious draws. We only put 117 AH through the system with a total capacity of 990 AH. This morning the SOC was 12.2. I' starting to think that I need to check the settings inside the controller. Still working under the assumption that we need to bring the batteries up to full charge but the controller says that happened.??????
KauaiMolokai
Solar Enthusiast
- Joined
- Dec 25, 2019
- Messages
- 283
Hi spinoeca, Enjoy Baja! Do you have a voltmeter with which you can read the voltage at the batteries while they are charging during sunlit hours?
yes-just finished a predawn SG survey of all 12 cells as well as voltmeter readings on the battery pack. Am enjoying Baja despite this issue
KauaiMolokai
Solar Enthusiast
- Joined
- Dec 25, 2019
- Messages
- 283
Great. Once the sun is up and the cells are charging, presumably from the charge controller, let me know what the voltage reading at the battery is, ie the charging voltage. Have a great day. I have a bunch of old batteries I worked on for months on Kauai, and I learned a little about charging them, and determining when they were of no further value, and perhaps this can be of assistance to you.
I checked while it was equalizing and there was a -1.5v discrepancy between the batteries (with multimeter) and what the Xantrex C-40 was recording. I do not know if this is a function of the equalization or ? Otherwise the batteries track the Charge controller except there is a -0.2 discrepancy between the batteries (with multimeter) and the controller. My issue around this is does that affect charging enough to worry about, presumably the boundary between bulk and absorption is affected. These are brand new batteries to us on 19th Dec., the girlfriend's BD. Thanks for your interest
Make sure your hydrometer is accurate. Maybe get another one to be sure. When I bought our L16 batteries I chose Crown to save money. When I got them home the SGs were low. So I equalized the crap out of them and the SQs never came up to full. Took them back for some Trojans (which cost a fair amount more) and had the same problem. Bought another Hydrometer (same brand) and realized the Trojans were fully charged. Compared the two Hydrometers and the one reading low had the markings off. Low one came from battery seller and was likely old stock. New one was from Amazon and presumably newly manufactured. Hydrometer sellers are not subject to recalls. They realized their mistake but didn't worry about the bad manufacturing runs.
thanks for that suggestion but I bought one different from the one my solar contractor had let me borrow, used it and it gave the same readings as the solar contractor owned hydrometer and so did yet another one when I dropped and broke my first one (which I also did last year). I might just buy a refractometer based one or one that is digital as neither of the ones available here are easy to read. Replacing these batteries under warranty will be difficult since we are south of the border but I may have no choice. I have equalized 3-4 times with little in terms of result but may try again tomorrow.
If you have another option to run your loads I would break them apart and charge the batteries separately. You will know pretty quick by overcharging one or two if you can bring them back. An old school 10/2 amp 6v charger is perfect for your situation. Put it on manual mode and let it charge away while you check SQs periodically.
A 1.5V discrepancy suggests a loose or bad connection between the charge controller and the battery bank. This will prevent the battery from charging.
You need to stop equalizing until you know what's going on. Equalizations should only be done AFTER the battery is fully charged. They can be detrimental otherwise.
- Your batteries should be getting up to 15.00V.
- You should be charging them somewhere around 89A if possible.
- Your batteries aren't fully charged until they are at 15.00V AND the current drops below 27A.
I suspect you are grossly over-using them and undercharging them and/or you have a bad/weak/loose connection between the chargers and the battery.
I wish we were grossly overusing them, that way I could retire the flashlights. We do run a rather old 32" TV for about 3 hours a night but otherwise lights are low wattage, reefer and stove are gas. Until we replaced the batteries on 12/19 we were doing just fine with 220AH capacity. With 4 times the storage/useable power we thought we would be rolling in the power, I believe that the solar contractor did a good job connecting the batteries and it is the same setup we had with old batteries including a heavier gauge wire which was run in Nov. The 1.5v discrepancy was only during equalization, normally the batteries are 0.2 above what the controller is reporting. I think the indictment that we are undercharging is true, we can only muster a max of 33 amps BUT the controller records the battery as being full and the voltage drops to 13.6 under, I assume, absorption. We initially used a generator to augment the charge, through a 90 amp battery charger connector directly to the batteries but it was only a 2800 watt generator and I think the contractor got a little frustrated because we couldn't wire it directly into the inverter (only accepts 220v which neither of my generators can provide) which the contractor bought and installed. Maybe I should disconnect the batteries and charge them separately with the contractor's 10kw gennie and his 90 amp charger. Thanks for the input and happy new year
"Belief" needs to be supported by data. Believing they were installed correctly doesn't cut it.
0.2V could be chalked up to instrument error/calibration. 1.5V is outrageous. It indicates a SERIOUS issue and needs to be resolved.
From:
You need to read the entire document I linked and follow it.
You need to triple the size of your array to meet the 10-20% requirement. You will need to upgrade/add charge controllers to handle this. This should have been a recommendation by your "solar contractor" before they sold you the batteries. You will damage these batteries and shorten their life if you don't.
Here's how a proper charge should go:
Apply 89A of current to battery until 15.0V is achieved.
Hold 15.0V by decreasing current until current drops to 17.8A
At that point, the battery is fully charged.
If you are charging at less than 89A, and/or if you are charging at lower than 15.0V, and/or you are not holding 15.0V until your current drops below 17.8A, your batteries are undercharged and will never reach SG of 1.260-1.280. You should never equalize a battery that is not already at full charge according to the above criteria.
Again, please read that manual. You need to adopt best practices described therein to ensure you get the most out of your investment.
0.2V could be chalked up to instrument error/calibration. 1.5V is outrageous. It indicates a SERIOUS issue and needs to be resolved.
- Are the chargers configured to hit 15.0V during charge?
- Have you witnessed the batteries hit 15.0V during charge?
- Have you confirmed that all connections between the charge controller and battery are tight and secure?
- What is the gauge of wire between the charge controller and the battery?
From:
You need to read the entire document I linked and follow it.
You need to triple the size of your array to meet the 10-20% requirement. You will need to upgrade/add charge controllers to handle this. This should have been a recommendation by your "solar contractor" before they sold you the batteries. You will damage these batteries and shorten their life if you don't.
Here's how a proper charge should go:
Apply 89A of current to battery until 15.0V is achieved.
Hold 15.0V by decreasing current until current drops to 17.8A
At that point, the battery is fully charged.
If you are charging at less than 89A, and/or if you are charging at lower than 15.0V, and/or you are not holding 15.0V until your current drops below 17.8A, your batteries are undercharged and will never reach SG of 1.260-1.280. You should never equalize a battery that is not already at full charge according to the above criteria.
Again, please read that manual. You need to adopt best practices described therein to ensure you get the most out of your investment.
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If you hit ENTER after every portion to which you wish to respond, it will keep my text quoted and your response will be separated. At this point, I can't reply to the specifics on context.
Any quality contractor should know that flooded lead acid needs to be charged at 10-20% it's capacity. 890Ah of batteries should be charged at 89-178A. There is no excuse for this oversite. It's incompetency.
If you see 1.0V higher at the controller, that means your battery is never getting over 14.0V if the controller is reading 15.0V. The BATTERY must be at 15.0V. Given that the cables have been replaced, I suspect that they are not installed properly, or some component (fuse/breaker) has high internal resistance and should be replaced.
This 1.0V drop needs to be resolved ASAP. It is the primary issue. Even if you add more panels, this will sabotage efforts to charge the battery.
How are you charging with your generator?
Can you purchase a cheap generator with 220VAC output and use your inverter/charger? My 3500W continuous generator cost $399. That alone could get you over the hump. Depending on your inverter/charger a smaller generator may suffice.
Any quality contractor should know that flooded lead acid needs to be charged at 10-20% it's capacity. 890Ah of batteries should be charged at 89-178A. There is no excuse for this oversite. It's incompetency.
If you see 1.0V higher at the controller, that means your battery is never getting over 14.0V if the controller is reading 15.0V. The BATTERY must be at 15.0V. Given that the cables have been replaced, I suspect that they are not installed properly, or some component (fuse/breaker) has high internal resistance and should be replaced.
This 1.0V drop needs to be resolved ASAP. It is the primary issue. Even if you add more panels, this will sabotage efforts to charge the battery.
How are you charging with your generator?
Can you purchase a cheap generator with 220VAC output and use your inverter/charger? My 3500W continuous generator cost $399. That alone could get you over the hump. Depending on your inverter/charger a smaller generator may suffice.
Exactly, I was thinking for the short term to adjust the bulk charging pot to 15 as opposed to the 14.2 it is now set at but am a little timid to do that and I do understand that that will not give me the 15v but since I am short on the current anyways....
Don't have the battery charger anymore so am not able to go that route for the time being. I was running the small (2800 watt) RV generator to power the 90 A battery charger but not enough juice coming out of the gen to utilize the full potential of the generator.
That was a step I was going to take anyways but with the inevitable delay of getting something here I kept procrastinating. Thanks again for your input
The bulk current should be set to 15V anyway as that's the bulk voltage for your batteries. Failure to charge to that voltage means, they're undercharged. Undercharged batteries don't last as long. If your batteries are never getting over 13.2V, this explains almost everything.
Concerning the charger:
90A * 14V = 1260W
1260W / 110VAC = 11.5A
The 110VAC plug on a generator should sustain 15A, so I can't understand why you couldn't get the full 90A out of it.
Okay... RV now mentioned... is this on an RV, or is the RV separate from the solar installation? If you have an RV, it should have an AC/DC converter capable of charging the battery typically with 30-55A. In most cases, those are removable in short order. This is a situation that needs to be rectified ASAP, so any resources that can get your battery charged need to be exploited.
Looping back around to the 1.0V difference, I would encourage you to personally check that everything is secure between the charge controller and the batteries. You indicated those wires were replaced. That means they've been loosened and should have been tightened. If there are breakers and fuses in the connection, you need to measure voltage across those components when the current is at max. Any notable voltage means the connections to it are loose, or the component is failing.
Concerning the charger:
90A * 14V = 1260W
1260W / 110VAC = 11.5A
The 110VAC plug on a generator should sustain 15A, so I can't understand why you couldn't get the full 90A out of it.
Okay... RV now mentioned... is this on an RV, or is the RV separate from the solar installation? If you have an RV, it should have an AC/DC converter capable of charging the battery typically with 30-55A. In most cases, those are removable in short order. This is a situation that needs to be rectified ASAP, so any resources that can get your battery charged need to be exploited.
Looping back around to the 1.0V difference, I would encourage you to personally check that everything is secure between the charge controller and the batteries. You indicated those wires were replaced. That means they've been loosened and should have been tightened. If there are breakers and fuses in the connection, you need to measure voltage across those components when the current is at max. Any notable voltage means the connections to it are loose, or the component is failing.
Update. Prompted by suggestions from this website as well as other research I was able to conduct I typed out a plan of action to rescue my batteries. Get them charged as per the Rolls website, purchase a bigger controller, buy more panels and get a 240v generator. I put this down on paper and had it in an envelope (with a Spanish translation) ready to pass to my contractor. He showed up with his workers and began by unloading 4 different (and I assume new based upon the fact that he received 24 new ones after the 4 he brought down for me) batteries with good SG and charged over the weekend. He had some 485 watt PV panels for another job but he had others so we agreed to install 4 more in my system. He told me I would need a bigger controller and we will be installing an 80 amp one he has in stock. It will be located in the battery room and not in our bedroom, quite a run from the battery room. So everything is good with the install slated for Friday. Thanks for the input. I never gave the contractor the letter. Maybe I should write a letter wishing for world peace?
