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Hydrometer results

SolarSamSurfer

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Apr 24, 2022
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G'day, some of you may have seen my other post where ive been having problems with my batteries, i was told to get a hydrometer so here i am back with the results. they are all lead acid with 6 cells.
Battery one 13.1v at test time. Battery manufactured 5/21 Used for 6 months.
cell one: 1183
cell two: 1183
cell three: 1183
cell four: 1183
cell five: 1178
cell six: 1168

Battery two 10.9v at test time. Battery manufactured 5/21 Used for 6 months+
Cell one: 1183
cell two: 1158
cell three: 1168
cell four: NA (didnt give reading it was so low)
cell five: 1158
cell six:1158

Battery three 13.25v at test time. Battery manufactured 4/22 Used for two weeks
Cell one: 1198
cell two: 1208
cell three: 1208
cell four: 1208
cell five: 1218
cell six: 1218

Battery four 13.05 at test time. Battery manufactured 11/21 used for 4 months
cell one: 1183
cell two: 1183
cell three: 1178
cell four: 1183
cell five: 1183
cell six: 1183


With these results what do i do now? The first two batteries still have warranty until Tuesday. On monday i will drive 2 hours to the supplier to get battery 2 changed, should i also ask for battery 1 to be changed? I was going to take them all to get them all charged up.
 
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Actually 1.183 not 1183. Make sure you have electrolyte at proper level and don't make measurements right after you add water until you give it some charging to mix it up.

Lead acid state of charge and specific gravity.png
 
Based on the results you posted, none of these batteries are at a full state of charge. Charge until specific geavity comes up to indicated value for "chg state" = 100. If the specific gravity does not come up after a day of charging (good sun), you'll need to run an equalization cycle on the battery. check the specific gravity every few hours or so while charging.
 
Those values indicate a low state of charge. Are those temperature compensated readings? Did you add water right before checking the SG? Also, did you check voltage right after removing from the charger? To be accurate, the voltage needs to be measured about 12 to 24 hours after resting off the charger for 12 to 24 hours. Or you could put a load on the batteries for a short while first to remove the surface charge.

I suspect your batteries are never being getting charged. In your other thread, you say the batteries are getting fully charged, but how were you determining that? To get a 48v bank of lead acid batteries fully charged, you need to be charging at > 57.6v for at least a couple of hours a day.

Definitely get the battery with the dead cell replaced.
 
Those values indicate a low state of charge. Are those temperature compensated readings? Did you add water right before checking the SG? Also, did you check voltage right after removing from the charger? To be accurate, the voltage needs to be measured about 12 to 24 hours after resting off the charger for 12 to 24 hours. Or you could put a load on the batteries for a short while first to remove the surface charge.

I suspect your batteries are never being getting charged. In your other thread, you say the batteries are getting fully charged, but how were you determining that? To get a 48v bank of lead acid batteries fully charged, you need to be charging at > 57.6v for at least a couple of hours a day.
Well, as we can see, he's got a battery with a dead cell. It was probably draining and preventing his other batteries from getting a good charge. Once he gets the battery replaced, does the maintenance needed, tops up everything to full, including electrolytes, and reassembles in series, he'll probably be fine.
 
What is the system voltage? If its not 48 volt how are they wired? They are all low and #2 lower. Bulk charge then absorb for a few hours. Let them sit for a hour if that 1 cell hasn’t came up to near 1.20 it’s probably not going to.
 
Short explanation on lead-acid battery.

Discharge takes sulfuric acid and splits it to sulfur that gets combined with lead and sticks to plates and leaves water behind from H2SO4 acid. This makes electrolyte more watery (lower SG), less acid.

Charging reverses process and return acid to electrolyte and removes sulfate from plates.

Problem is if not kept fully recharged, the lead-sulfate on plate hardens and does not reconvert during charging. SG will not completely rise where it should be.

Controlled overcharge (equalization) will get back semi-hardened sulfate and can chip off hard sulfate so it drops to bottom of cell. At least you get the plate surface fresh lead instead of being blocked by lead sulfate which is insulator. The hard crystals that drop to bottom of cell will take sulfur with it so you will not get full SG back at best charge you can do.

Try some equalization charge. Make sure you replenish water as the vigorous bubbling is electrolysis of water (hydrogen and oxygen gas) that eats up water in electrolyte.
 
Thanks for the replies guys on Monday i am going to make the long drive to battery supplier change the battery with the dead cell, i am also going to talk to them to see if they could run an equalization for me on the other batteries and if not i will do it myself. The battery is from the biggest battery company in Mexico called LTH if any of you are interested. I have my doubts if the people working there even know what an Equalization is because in the last 4 months ive changed 3 batteries there and asked them for any advice and they haven't even told me about a hydrometer or equalization before just to check voltage and water level. When i go in on monday if they dont seem to know what im talking about when i ask them to preform Equalization i will buy a bench top power supply as i think its the only way ill now for sure the batteries are getting 14.4v. How long do you normally bring voltage to 14.4v when doing equalization?
 
Also since this battery trouble began i watching my system more closely and found out that once my inverter reaches float and my load drops due to my fridge turning off (its the only heavy load otherwise i have some LED and a 12w modem) that the inverter starts changing voltage 52-60v sometimes going over 60v triggering the overload protection but as soon as its reset it goes back to changing from 52-60. I noticed it happens until the sun isnt as strong normally 2 hours before dark. Does this sound like a problem related to my batteries or does it sound like an inverter firmware problem? Its the next thing i need to organize once i have my batteries organized because i don't want to connect them to the inverter if its going to keep happening because im sure its not good
 
The manufacture should have documents on the proper voltage and current for each phase of charging. You need to find it and set your charger settings to match those. Batteries should be lasting years not months.
 
The manufacture should have documents on the proper voltage and current for each phase of charging. You need to find it and set your charger settings to match those. Batteries should be lasting years not months.
Yes they should but i live in a developing country in a rural area so the people are not so educated which is why i am turning to DIY.
 
Also since this battery trouble began i watching my system more closely and found out that once my inverter reaches float and my load drops due to my fridge turning off (its the only heavy load otherwise i have some LED and a 12w modem) that the inverter starts changing voltage 52-60v sometimes going over 60v triggering the overload protection but as soon as its reset it goes back to changing from 52-60. I noticed it happens until the sun isnt as strong normally 2 hours before dark. Does this sound like a problem related to my batteries or does it sound like an inverter firmware problem? Its the next thing i need to organize once i have my batteries organized because i don't want to connect them to the inverter if its going to keep happening because im sure its not good
Please post your growatt configuration (i believe that's the inverter/aio you have, correct?). I don't know growatt, but there are plenty here who do. Someone may be able to explain this behavior and suggest changes.
 
Thanks for the replies guys on Monday i am going to make the long drive to battery supplier change the battery with the dead cell, i am also going to talk to them to see if they could run an equalization for me on the other batteries and if not i will do it myself. The battery is from the biggest battery company in Mexico called LTH if any of you are interested. I have my doubts if the people working there even know what an Equalization is because in the last 4 months ive changed 3 batteries there and asked them for any advice and they haven't even told me about a hydrometer or equalization before just to check voltage and water level. When i go in on monday if they dont seem to know what im talking about when i ask them to preform Equalization i will buy a bench top power supply as i think its the only way ill now for sure the batteries are getting 14.4v. How long do you normally bring voltage to 14.4v when doing equalization?
If you do buy a bench top power supply, you will need to create your own leads with ring terminals connecting to the power supply and battery terminals suitable for connecting to your batteries.

Please post pictures of your system. Inverter, batteries, panels, wiring.
 
I found this on the net. If this is your battery these are the charging voltage’s you should be using.
 

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Cool acdoctor, so according to that spec sheet, absorption charge (literally "trickle") should be 14.8v, float should be 13.2v and equaliztion should be 15.5v.

So that means that during regular charging, the batteries should see 59.2v. Is that close to what you see, SolarSamSurfer?
 
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I found this on the net. If this is your battery these are the charging voltage’s you should be using.
Thanks for this info! I was going to ask for this info tomorrow when i go in to change the battery but i guess now i don't have to! What do you think of the batteries based on the info you can see? they cost 250-300 USD each new!
Cool acdoctor, so according to that spec sheet, absorption charge (literally "trickle") should be 14.8v, float should be 13.2v and equaliztion should be 15.5v.

So that means that during regular charging, the batteries should see 59.2v. Is that close to what you see, SolarSamsurfer?
Honestly no I just had my inverter set to the default settings of 58.4v because the engineer who sold me the equipment told me the default settings where fine. Again why im turning to DIY because it seems like the engineers around where i am dont really know what they are talking about. Once i get the batteries ready to go ill change my Config! Also those values are for 25c which i only get for a few hours in the evening, in the day time its never under 30c or 85f and is normally 33c or 91f. How should i adjust the values for a warmer temp

If you do buy a bench top power supply, you will need to create your own leads with ring terminals connecting to the power supply and battery terminals suitable for connecting to your batteries.

Please post pictures of your system. Inverter, batteries, panels, wiring.
Tomorrow when i go to the bigger town where the battery supplier is i will check to see if i can find a shop selling them so i dont have to wait for one to come from the internet. Can you send me a photo of your leads so i can get the pieces tomorrow while im in town! Also is Wanptek a good power supply? They are the only ones that i can find locally on the internet. model NPS 3010w or KPS 3010DF. I think i will hold off posting pictures of my system until i get back from the town tomorrow because its in pieces since I've dissembled the batteries. My batteries are currently wired with 6AWG and the cables dont get warmer then room temp which is normally 33c or 91f. Should i buy 2AWG cable for my batteries? I would like to start shopping for the voltage equalizer you recommended so that it can start is journey to my place. Ive had a look and cant find any locally so is there any brands you can recommend since i have to order from overseas.

Side note will my SG for SOC be differant for me in the tropics? this webpage says its a bit differant but they might not be accounting for temp change in there calculations. The hydrometer i have adjusts for the temp.
 
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Thanks for this info! I was going to ask for this info tomorrow when i go in to change the battery but i guess now i don't have to! What do you think of the batteries based on the info you can see? they cost 250-300 USD each new!

Honestly no I just had my inverter set to the default settings of 58.4v because the engineer who sold me the equipment told me the default settings where fine. Again why im turning to DIY because it seems like the engineers around where i am dont really know what they are talking about. Once i get the batteries ready to go ill change my Config! Also those values are for 25c which i only get for a few hours in the evening, in the day time its never under 30c or 85f and is normally 33c or 91f. How should i adjust the values for a warmer temp
Did the Growatt come with a temperature sensor for the batteries? Most FLA capable chargers do, so they can adjust charging to compensate for battery temperature. I know my EPEVERs did, and my Samlex EVO inverter/charger did (neither of which I use). That sensor will go onto the main negative terminal of the battery and will connect into the receiver port on the growatt, if so equipped. Need someone experienced with the growatts to comment more on this.
Tomorrow when i go to the bigger town where the battery supplier is i will check to see if i can find a shop selling them so i dont have to wait for one to come from the internet. Can you send me a photo of your leads so i can get the pieces tomorrow while im in town! Also is Wanptek a good power supply? They are the only ones that i can find locally on the internet. model NPS 3010w or KPS 3010DF. I think i will hold off posting pictures of my system until i get back from the town tomorrow because its in pieces since I've dissembled the batteries. My batteries are currently wired with 6AWG and the cables dont get warmer then room temp which is normally 33c or 91f. Should i buy 2AWG cable for my batteries?
What is your inverter size again (in watts)? Divide the watts by the battery voltage (48) To get current (in amps) your inverter might use. Based on the battery voltage, amps, and length of the battery cables (roundtrip battery to inverter and back to battery), use a voltage drop calculator to determine what your wire size should be. You want less than a 3% voltage drop. Size the fuse at 1.25 times the amps. There are voltage drop calculator links posted all over this forum. You'll have to do a little leg work there. Maybe I'll add one to my signature at some point.

I would like to start shopping for the voltage equalizer you recommended so that it can start is journey to my place. Ive had a look and cant find any locally so is there any brands you can recommend since i have to order from overseas.
Search around this forum or start a separate thread. I do not have experience with these devices myself, and cannot make a suitable recommendation.

Side note will my SG for SOC be differant for me in the tropics? this webpage says its a bit differant but they might not be accounting for temp change in there calculations. The hydrometer i have adjusts for the temp.
One of mine is Wanptek, and it has worked fine for me. You can find one that Will recommends here: https://www.mobile-solarpower.com/tools.html

That said, if you can get it local and they offer warranty exchanges, then go for it.

As for my leads, I use ring terminals suitable for 1/4" diameter studs (at the power supply) and quick connect heatshrink male molex terminals at the other end. I permanently installed quick connect female shrouded molex terminals on my 24V FLA bank. When I need to, I just make the connections and I am good to go. It may be simpler for you to find suitable clamp-style connectors that will fit your battery terminals.

Here is an example of a ready-built pair: https://www.amazon.com/dp/B0768CW328/ref=cm_sw_r_cp_api_i_31W82H9KVSBQCJNWF1Z1?_encoding=UTF8&psc=1

Side note, when you go to use the power supply, turn it on and set the voltage BEFORE connecting the leads to the battery, otherwise your voltage setting will be incorrect (too high) and you could damage the battery. The PS (short for power supply) should come with an instruction manual. When in doubt, read it.

As for temperature adjusted SG, @RCinFLA can probably answer that better than I can.
 
Side note will my SG for SOC be differant for me in the tropics? this webpage says its a bit differant but they might not be accounting for temp change in there calculations. The hydrometer i have adjusts for the temp.

I think what that web page you linked to about SG differences in the tropics is that in hot climates, battery manufacturers can sometimes use a weaker acid solution to help the batteries live longer, as the chemical reactions in a lead acid battery happen faster in hotter average temperatures. A weaker acid solution is used to help the battery last longer (with the same performance). I had forgotten about that. If you could get a SG specification from the maker of your batteries, that would be very good. If they are designed to have a weaker acid solution, then the charts you read from North America will be a little off and state a higher SG to SOC ratio.

You can get a good idea about what the full charged SG value is with the new battery you will be picking up. If you charge it up with the power supply at 14.8v until it is charging at under 1 amp for an hour and then read the SG, then you'll know what the SG is at full charge.
 
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