Built A tiny home, but it has solar issues

[chrisski]

The top two wires are empty.

The bottom red and black shoulf go through the wall to the respective batttery + and - terminals. This reads voltage.

The Middle two get routed to the shunt. THe blue wire gets connected to the part of the shunt that is closest to the battery. The yellow wire gets connected to the opposite terminal of the shunt. This reads amps.

With no loads on, the battery monitor should be pretty close to what the solar panel is putting out for charging amps. If the SOC is staying at 100% all the time, may be that the amp cables (blue and yellow) are backwards. Needs a negative amps to go below 100%. Kind of hard o tell from the pic, but appears yellow and blue may be reversed at the shunt. If this is true, charging with the solar panel will read a negative amperage.

You will need to adjust the monitor to the correct size in AH for the battery you have for the SOC tone accurate.

[The_realTW]

The top two wires are empty.

The bottom red and black shoulf go through the wall to the respective batttery + and - terminals. This reads voltage.

The Middle two get routed to the shunt. THe blue wire gets connected to the part of the shunt that is closest to the battery. The yellow wire gets connected to the opposite terminal of the shunt. This reads amps.

With no loads on, the battery monitor should be pretty close to what the solar panel is putting out for charging amps. If the SOC is staying at 100% all the time, may be that the amp cables (blue and yellow) are backwards. Needs a negative amps to go below 100%. Kind of hard o tell from the pic, but appears yellow and blue may be reversed at the shunt. If this is true, charging with the solar panel will read a negative amperage.

IMG_8180.JPG

Ok I reversed the wires, here is the readout now, I am currently backfeeding the generator through the converter, the inverter and solar system side are powered down.

You will need to adjust the monitor to the correct size in AH for the battery you have for the SOC tone accurate.

IMG_8181.JPG

No clue how to do that as this thing does not seem to be programmable

SOC is unchanged.

I can try to shut the backfeed down in a couple hours and see if SOC moves

[Bala]

I WANT TO BE CLEAR I MEANT NO OFFENSE, EVERYONE is welcome and needed here. I did not mean for my post to sound short. Your "Different perspective" is completely welcome.

No offense taken, but you didnt reply to my question, I will ask another,


You say your batteries are good, what test have you done to determine that they are good?

[The_realTW]

Posting this to Kill two birds with one stone

chrisski: no change on SOC level throughout the night or today

Bala: in answer to your question: the batteries were purchased in September 2020 brand new , even though it seems unlikely, they had to charge between the install (sept 2020) and me fixing the current issue (putting on the - lead back to the shunt from the SOC) even if very slowly. There is absolutely no way that I would have had ANY POWER at all if the batteries were not giving it.

also they were fully discharged and then charged back up at a Lincoln Interstate batteries outlet, and declared healthy. This took place two weeks ago.

everyone: the main issue was never whether the batteries were working or the panels, although I will admit that these other issues had us all looking for culprits. It comes back to the fact that this SCC, panel count, and battery count is just insufficient for the use cycle I wish to get from it.

last night I was at 29% battery (after a cloudy day) and I put the generator on and turned on the backfeed through the converter, I did this at 10pm- and at 1am I shut the generator down with the SOC on the SCC reading 13.4 volts and 99% charged. I went to bed soon after so obviously it didn’t stay that way, but those three hours seemed to help through the night, no more alarms.

obviously I want the whole night to pass with stored energy but these batteries (or the amount) just can’t do that. I always found that bizarre as it’s just the stupid fridge that is on when I’m in bed, anyway I digress.

the main point is I am going to design a system that has more PV Absorption, more stored capacity, and a faster SCC, also I want to set something up that will allow the panels to be manipulated during the day. I’m looking at tracking systems but they are very heavy (maybe I can build a turret lol) but I am also looking at adjustable rails that can be moved throughout the day, although ideally I could get enough to lay them flat and just get my power that way.

this is obviously a developing situation and more will unfold as we progress,

ok that’s all for now, and chrisski, I’m still convinced that “monitor” is either not setup right or just won’t give me the info I need!

[Bala]

Posting this to Kill two birds with one stone


last night I was at 29% battery (after a cloudy day) and I put the generator on and turned on the backfeed through the converter, I did this at 10pm- and at 1am I shut the generator down with the SOC on the SCC reading 13.4 volts and 99% charged. I went to bed soon after so obviously it didn’t stay that way, but those three hours seemed to help through the night, no more alarms.

obviously I want the whole night to pass with stored energy but these batteries (or the amount) just can’t do that. I always found that bizarre as it’s just the stupid fridge that is on when I’m in bed, anyway I digress.

ok that’s all for now, and chrisski, I’m still convinced that “monitor” is either not setup right or just won’t give me the info I need!

After a charge with your battery V @ 13.4 they are not at 99% charged so cant get you through the night, so you are correct your meter is not set up right.

Basically they will have now been grossly undercharged since the charge and test 2 weeks ago. If you do not get them charged back up properly they will be dead sooner rather than later.

Your only option to have a hope of saving these batteries at the moment is to use a generator to charge and a hydrometer to test SOC.

[The_realTW]

After a charge with your battery V @ 13.4 they are not at 99% charged so cant get you through the night, so you are correct your meter is not set up right.

Basically they will have now been grossly undercharged since the charge and test 2 weeks ago. If you do not get them charged back up properly they will be dead sooner rather than later.

Your only option to have a hope of saving these batteries at the moment is to use a generator to charge and a hydrometer to test SOC.

They did good last night, no alarms at all..

As for the meter I doubt there is anything that can fix that, its a 15 dollar cheapy

I charge them every night for three hours with the backfeed, if they die they die, I will be replacing them entirely anyway.

I only have the tiny home until Saturday, when it goes back in storage. I do not own a hydrometer. The SOC is probably accurate on the SCC panel, but I am unsure if it is on the meter itself.

[chrisski]

I use a hydrometer from an auto parts store.

Not the cheap one with three little floating pellets, but the one with a glass floaty. It may cost $8 to $12. No need for a temperature compensating $25 one if you can add or subtract based off temps.

Getting SOC from voltage is not always accurate; they need to sit idle a while, but the hydrometer won’t lie and will tell you which cells in both your batteries are good or bad.

[The_realTW]

I use a hydrometer from an auto parts store.

Not the cheap one with three little floating pellets, but the one with a glass floaty. It may cost $8 to $12. No need for a temperature compensating $25 one if you can add or subtract based off temps.

Getting SOC from voltage is not always accurate; they need to sit idle a while, but the hydrometer won’t lie and will tell you which cells in both your batteries are good or bad.

Interesting, and your recommending I purchase one of these even though I fully intend to switch over to Lithium?

[The_realTW]

Would something like this work? I looked at the Victron monitor but it was close to 200 bucks! That is a bit pricey

https://www.amazon.com/Capacity-Percent-Battery-Monitor-0-120-0V/dp/B01FXQUMCG/ref=sr_1_19?dchild=1&keywords=solar+battery+monitor&qid=1620185753&sr=8-19

[chrisski]

Before going to lithium’s there’s some steps to keep flooded lead acid batteries longer, like going to equalization mode an hour at a time until the cells are balanced. My cells were slightly out of balance when measured with a hydrometer, but after equalizing for only on hour, the specific gravity in each cell remained the same.

For a a good write up on equalization, check in the stickies in the battery section.

I think you have flooded lead acid batteries, and if so, an equalization could help.

Looking at the link you posted, that monitor may work. It looks like it is designed to hook into a shunt, and you already have one connected. One of the reviews talk about the instructions list the incorrect steps to cal the monitor. It’s a shame the monitor you have now comes without instructions. There’s gotta be a way to cal the one you have, but without instructions, there may as well not be.

[The_realTW]

Before going to lithium’s there’s some steps to keep flooded lead acid batteries longer, like going to equalization mode an hour at a time until the cells are balanced. My cells were slightly out of balance when measured with a hydrometer, but after equalizing for only on hour, the specific gravity in each cell remained the same.

For a a good write up on equalization, check in the stickies in the battery section.

I think you have flooded lead acid batteries, and if so, an equalization could help.

Looking at the link you posted, that monitor may work. It looks like it is designed to hook into a shunt, and you already have one connected. One of the reviews talk about the instructions list the incorrect steps to cal the monitor. It’s a shame the monitor you have now comes without instructions. There’s gotta be a way to cal the one you have, but without instructions, there may as well not be.

The move to Lithium is more of the fact I want those batteries lighter, inside and not on the tongue, and even though they cost an arm and a leg you cannot argue (And believe me I have been trying to) the long term benefits of the technology of the LIPO4, I realize it will mean some serious cash, and probably redoing the entire system, but lets face it this system never worked properly.

As for equalization I saw something in the SCC about doing that once every 30 days, however I did not see a way to manually initiate it

that monitor may have something out there, ill do some digging

[The_realTW]

Chrisski,

I believe this is our guy, going to try it now!

http://www.lyonscomputer.com.au/Electronic-Devices/Battery-Meters/PZEM-015-Multifuctional-Battery-Meter/PZEM-015-Multifuctional-Battery-Meter.html

[The_realTW]

Ok I think I have it setup, problem is the shunt that came with this monitor (which I never saw lol) was rated at 200A, the system is 420 AH, so I am presuming the shunt must be rated for at least the same as the fuse, which is 500A as well.

I think its as good as its going to get, this monitor is not setup for this system (just another reason why it is all getting changed out), OH BTW I set the Amps for 50A (Options were 50-100-200-300) and now the amps charging on the SCC and the monitor are close to synced, but they are still off.

SOC is better though

IMG_8216.JPG

[The_realTW]

Oh btw ( would have edited the previous post to add this but we all know what happens when we do that) the SCC DOES NOT allow the equalization to change, that I can see. So I am not sure how that would work!

[Mike90250]

if I understand, you are putting Li batteries on the trailer tongue ? That leaves them vulnerable to frost. Frosty Li batteries CANNOT be charged without destroying them. You BMS may have a temperature cut off at 33F, most do not.

Li batteries do not ever get Equalized. They get balanced, which is a long, slow, gentle process 1x a year.