I too need help with loss of battery storage.

LndSchneid

Thanks again so much, Bill.  Kevin will once again be apprised and I will convey.
Linda

LndSchneid

Bill,
The 1500 inverter is showing 55% here at 7:30 pm, with the piano heater unplugged for hours.  It's still light outside.  Normally it's been showing 70% or mid to high 60s with the piano heater plugged in with the 3000 inverter. The alarm even just rang when my chest freezer kicked on.
Linda

BB.

Sounds like the battery bank is under charged.

Do you have a decent DMM (measure 12.xx voltage range?) and a hydrometer to measure specific gravity of your batteries?

Short term answer is to figure out battery bank present state of charge, and to get it quickly recharged to >90% state of charge... Take SG readings of all cell (and voltage of each battery)--Batteries and cells labeled (A1-3, B1-3, for first string, etc.).

Next, you probably need to get a genset and AC battery charger that can get at least 5% rate of charge:

• 0.05 rate of charge minimum  * 1,950 AH battery bank = 97.5 Amp rate of charge

You have a relativley large AH battery bank, and it needs a good size battery charger to charge correctly

• 97.5 amps * 14.5 amps * 1/0.80 est. charger eff * 1/0.80 max loading on genset = 2,209 Watt draw on genset (very rough estimates)

If your present solar array is outputting 400 Watts:

• 400 Watts * 1/14.5 volts charging = 27.6 amps

It would appear that your have issues with the solar charging--I would be expecting (on a cool/clear day) something on the order of:

• 800 Watt * 0.77 panel+controller derating * 1/14.5 volts charging = 42.5 amps (solar noon, may hit a few times a month)

And you said you have seen 100 to 400 watts on the controller.... You may still have system configuration issues (too small of cable from controller to battery bank, one or more solar panels not making good electrical connections, failing battery bank, etc.).

We need details from independent devices (Digital Volt Meter, Current Clamp meter--if you have one, hydrometer) to start to figure out what is going on.

And it will start with basics. Send us the voltage across each battery (i.e., A battery 6.00 volts early morngin, 7.30 volts charging, 6.4 volts evening with loads off).

Similar with each battery cell specific gravity measurements... For example, log the SG of each cell in the morning (just tell u when you took readings). A-1 1.160 SG, A-2 1.230 SG A-3 1.125 SG, etc...

Have you even check the electrolyte level in each battery (assuming flooded cell). Typically, they need to be refilled with Distilled Water every 1-3 months (don't fill to tip-top--just 1/2 to 3/4 filled or they will spill over when hot and charging).

I fear, at this time, your battery bank is on the ragged edge of having major problems (purely guess work here). At this point, to "save" your battery bank you need to A) know what its current condition is, like state of charge, each battery voltage, specific gravity for each cell, etc. and assuming the battery is undercharged, get it on a known good charger and get them back towards 100% state of charge (and more measurements to figure out where to go next).

C) also need you to measure your AC loads with a Kill-a-Watt type meter and/or with a DC Current Clamp meter (you can also measure the current from each solar string, charge controller panel input and charge controller output). And use the voltmeter leads to measure voltages everywhere in the system (on the solar charge controller input and output, battery bus, AC inverter DC input bus under load, etc.).

Yes, you are talking about buying some test gear ($100 - $200 or so test gear). Possibly a genset and AC battery charger (if you don't have the right gear yet), and start debugging the system.

And, frankly, if all was working 100% with what you have, the 800 Watt array is still way too small for your present battery bank. And at 100-400 Watts (around solar noon?) is not helping at all.

-Bill

BB.

Linda,

I would also add--If you have a friend or neighbor that knows a bit about car or boat electrical systems, they could help you with this too... Your handyman may not have the "free time" to do AM/NOON/PM system measurements and logging.

And we can help you interpret what is going on.

-Bill

LndSchneid

Bill,
Thank you again.  I feel I rapidly need to get more panels.  I am somewhat isolated and will not be able to get additional help to do any testing.

LndSchneid

So I just orderered 11 more 100 watt panels.  Here in 4 days.

BB.

Did you order a 2nd charge controller too?

And, on another note, can you get utility power to your place for a reasonable price. Going off grid and being your own utilty can be a difficult road to follow even in the best of conditions.

Even if it costs you $10,000+ to bring in power lines, it is probably a better "long term" investment than off grid solar power.

-Bill

LndSchneid

I have a second charge controller.  Will see if we can get it all set up correctly.  

LndSchneid

Hi Bill,

The new panels have arrived, not enough cables yet though, but what we have hooked up is already showing a radical improvement.  Once we have the new panels, second controller and second inverter connected, do we hae a separate battery section for each of the two set-ups, or do we channel both sets into the batteries as one?  Thank you.

Linda

BB.

Afternoon Linda,

You should have a central point or "bus bar" where all your dc connections are made.

Each positive wire comes off the bus and through a nearby & properly rated fuse/breaker (breakers protect the wiring from overheating).

Each controller should have its own wiring from the battery bus to each controller (home run or star wiring... All wiring starts at the dc bus).

The charge controllers generally are more accurate when done this way.

Note, always turn on the dc battery power to controller first, then turn on/connect the solar array.

It is possible to confuse or even damage a solar charge controller if the array {under sun} is connected first, then the battery.

Bill

LndSchneid

Thank you once again, Bill.  I will pass this on to my helper and keep you posted.

Linda

KenMorgan

Bill is a super great and patient Person, but you really, really need to check your SOC using a hygrometer, and if needed get a genset and charge them up. Have Kevin (or yourself) run a equalization charge.  you might need to do this a couple of times to get the batteries back up to their full capacity.  just the time that this thread has been running June 8th until the above post June 17th, is enough time to do serious damage to them. 

LndSchneid

Appreciate that very much Ken.  Bill is awesome too.  My neighbor who has the hygrometer to test the gravity just came back from being out of town so we're going to use that to test the batteries asap. In the meantime we now have two controllers, two inverters, adequate cabling according to the controllers, and 18 of the 20 panels set up.  I am at least able to run the humidity/heat bar under my grand piano 24/7, but despite surplus all day, there is still a significant drop come evening.  Battery check asap.  Thanks again.

BB.

Linda,

You may also be able to "play" with the piano heat bar... I would suggest that you turn it on when the room's temperature is rising, and turn it off when it is dropping... You just want the piano "warmer" than the rest of the room (i.e., turn it off at night and back on in the morning).

Generally condensation is more of an issue with the piano and a warming/humid room.

Other thinks that can help--If most of your nighttime loads are the piano heater (and say a couple LED lights to move around at night), a small AC inverter (100-300 Watts, depending on the heater and other loads) could be your 24x7 inverter... And the larger inverter is just used (for example morning/evening) when you have other loads (smaller inverters tend to waste less power than large inverters with small loads).

-Bill

LndSchneid

Thank you Bill.  Wouldn't I want the piano heater on at night and off during the day?  

BB.

It does depend on your house and its conditions...

You want to keep the piano "warmer" than its surroundings. A warming room (late morning thru evening) means the piano is colder than its surroundings--So it tends to collect moisture. A cooling room (night) means the room is cooler than the piano. (assuming your north coast weather is similar to where I grew up on the coast south of San Francisco).

Regarding mold... You want to not let the relative humidity rise above 60% humidity for 3 days... Mold needs >3 days >60% relative humidity to grow. If you get below 60% during any of that 3 day period, the spores go back into "hibernation".

I try to keep the RH below 60% all the time (when it goes >60% at all, I look for ways to reduce it--Typically open windows--if dry outside--heat room, or run dehumidifier. Also, look for reasons for high humidity--Gas stove with no ventilation, never opening windows for ventilation (moisture from people breathing, showers, wet dog, poorly ventilated crawl space, leaking pipes, dripping faucets, poor weather striping, house plants, etc.). If you live in a "coastal rainforest"--That is hard to "fix" without expending energy (electricity).

For really wet times, a dehumidifier (takes around 100 Watts just "running" the compressor perhaps at a 50% or less duty cycle), is really hard to beat (solar power--that is always an issue).

Generally, piano's don't like thermal cycles (can knock them out of tune pretty quickly). An insulated room with "controlled humidity" and no direct sun on piano is a start).

-Bill

LndSchneid

Thanks Bill. A lot of the desirable conditions are already in place for the piano.  It's good to have them spelled out.

Linda

LndSchneid

Bill and Ken,
When the controller showed both 60% this a.m. and then later at 100% charge, the battery fluid was at 1.27 in each battery cell both times..  Tested with a Robinar refractometer.  Tomorrow we can test with hygrometer.

Any input?

BB.

Sounds a little odd... Your 100% sg should run around 1.265 to 1.280 depending on initial fill, condition of battery, and temperature.

Hydrometer--Did you check calibration?

When charging, how much current and for how long (guesstimate).

Checking/logging the battery voltage (early morning, mid afternoon) of each battery can be a quick check too (battery voltage is roughly proportional to sg.).

And you are looking for batteries that are "different" from the rest of the group (significantly higher or lower voltage).

-Bill

LndSchneid

Hi Bill,

I'm not sure I totally understand what you're asking for, although Kevin is trying to help me understand. The maximum charge rate set by the controller is 13.2 volts.  It usually charges at 100% from 10 in the morning until 4 or 5 in the afternoon, with a small occasional change, during these sunny days.  Surplus runs 2-6 hours (full afternoon sun).

Linda

LndSchneid

Additional:  best charge is set at 13.2
Low is 12.6
Equalization is at 14.8; equalization time is 120 minutes every 30 days.
Charge disconnect is 16 volts
Low voltage disconnect at 11.1

BB.

You have L16 batteries which are generally 6 volt batteries. Two in series gives you a 12 volt battery string. The battery voltage can range from 11.50 volts (50% state of charge or less) to 14.75 volts or so (under charge--Controller charging setpoint). Or ~13.6-13.8 volts (afternoon, battery charged, charger getting sun on float setting).

Ideally, each battery should be 1/2 of the 12 volt battery bus voltage (i.e., 13.8 volts battery bus / 2 = 6.9 volts for each battery). You have a "matched" set of batteries and all of them should be very close to the same voltage. If you have one battery with high or low voltage, that many times indicates a problem.

Assuming you have flooded cell lead acid batteries, the charge controller set point should be around 14.75 volts for "absorb". 13.2 volt "absorb setting" is way too low. Voltages are at "room temperature" of ~77F... Very cold or very hot batteries will have different voltages.

Ideally, you should be seeing ~14.75 volts on the battery bus for 2-6 hours.

-Bill

BB.

EQ probably should be set to 14.9 to 15.1 volts (start with 14.9).

11.1 volts for LVD is a bit on the low side... But it may not make any difference if the LVD setting is on the solar charge controller.

Generally LVD is not used on solar charge controllers if you have an AC inverter (the inverter's LVD is usually set at 10.5--which is a "really dead" set of 12 volt batteries).

-Bill

LndSchneid

Okay.  Now we have to figure out how to override that automatic setting.  Hang tight.  Thanks again, ever so much.

LndSchneid

Hi Bill,
Here is Day 1 of my 2-day log.  I guess we are not limited to voltage after all.


6:37 a.m.  12.2 volts.  Controller says 57%
7:20.          12.3.                     59%
8:35.          12.3.                     61%
9:24.          12.7.                     77%
10:23.        13.6.                    100%
11:26.        14.1.                    100%
12:27.        14.7.                    100%
1:43 p.m.   14.7.                    100% + surplus
2:28.           14.6.                    100% + surplus
3:23.           14.6.                    100% + surplus
4:39.           13.9.                    100% + surplus
6:00.           13.7.                    100% + surplus
7:27.           12.6.                    71%
8:29.           12.5.                    69%

Start of Day 2

6:00 a.m.   12.3.                   53%


Thanks.
Linda
P.S.  I want to send you a sweet treat for all of your thoughtful help.  Is there any way to privately send me an address?

BB.

Linda,

Don't worry... We are here to help others (like those before that have helped us).

Your system seems to be charging correctly. Still would be nice to know how much energy you use overnight vs AH capacity of the battery bank... I wonder if the batteries are having problems (sulfating=lost capacity) or if you are simply using a lot of electricity at night.

The charge controller xxx% capacity estimate seems to be bit off around 100% (100% to 77% over a 1 hour period; your batteries are >90% SoC at ~1:43pm--which is an expected result based on charging voltage and time), but does give an "OK" estimate at lower SoC values(???).

-Bill

LndSchneid

Yes, that has been the challenge all along.  Why does it drop so rapidly within one hou  That has been consistent -- pre-additional new panels et al, pre-piano heater, and there is no more or less power being used than the rest of the day.  A dilemma.

BB.

Dropping from ~12.7 (resting voltage of fully charged batteries) to 12.6 volts is (roughly) only a 10% drop or a drop from ~100% to 90% SoC... (or more realistically from 90% "full charge" to 80% full charge).

Note achieving >90% full charge every day is just fine. Charging to 100% SoC every day, very hard on lead acid batteries.

-Bill

LndSchneid

So I need to run an appliance it appears.

BB.

Well, not really. You are still on the "ragged" edge of keeping up with your loads. You want the charge controller to hold ~14.7 volts for 2-6 hours... And you are holding for ~4 hours... Which is OK, but we are in the sunny weather season right now.

Having a more accurate estimate on energy usage (xx Amps current * 12 volt battery bus * X hours per day/night) would be helpful too...

In any case, you seem to be doing OK today. Getting a feeling about how the batteries and solar system perform when all is well, will let you see and catch problems when you see things not performing well.

-Bill