Problem with Solar Generator

Marc Kurth

Going 24v makes sense.

Have you run a true capacity test on your batteries lately? 

I would expect your particular battery bank when fully charged, to hold something like 12.1v to 12.3v running under a 150 amp load.
AT a 50% state of charge, a 150 amp load should pull you down to about 11.8v to 11.9v. 

I am wondering if higher resistance connections are a problem in your system.

I would start by removing the threaded-in SAE size post adapters from the batteries. Those are designed for automotive cable ends. You should be connected directly using the the same 8mm stainless bolt supplied, to land your cables right on the terminals.

When you unscrew the automobile post adapters, you will see that you will be getting about 3-5 times the surface contact area for your lug-to-battery connections.

lc0338

Marc Kurth said:

Going 24v makes sense.

Have you run a true capacity test on your batteries lately? 

I would expect your particular battery bank when fully charged, to hold something like 12.1v to 12.3v running under a 150 amp load.
AT a 50% state of charge, a 150 amp load should pull you down to about 11.8v to 11.9v. 

I am wondering if higher resistance connections are a problem in your system.

I would start by removing the threaded-in SAE size post adapters from the batteries. Those are designed for automotive cable ends. You should be connected directly using the the same 8mm stainless bolt supplied, to land your cables right on the terminals.

When you unscrew the automobile post adapters, you will see that you will be getting about 3-5 times the surface contact area for your lug-to-battery connections.

Have not ran a capacity test. would not know where to start. One of the things noted in these threads is that the + and - cables running to the inverter were not diagonal from the battery bank. I questioned the guy that set-up my system and he didn't think it was a problem but when I install the new inverter I will correct that situation which will take that little bit of resistance out of the system. I plan on using the same cables (as in the picture in earlier post) but will keep the auto connection cable ends in mind. I really don't expect any issues once I convert to 24 volt and get a good inverter.

Marc Kurth

Putting it as a question:  Why are you using the automotive posts on the batteries right now? 

You should just unscrew the brass "SAE automotive" adapter posts from the batteries. You don't want them there, they are working against you.

Once you have removed them, just attach your existing cable right to the battery, in the same threaded socket that the adapter post was screwed in. You will immediately that this gives you a much larger metal-to-metal contact area.

The female thread in the battery housing is 8mm. The thread where you are currently connected on top of the brass post is 8mm. 
Use the same bolt, the same cable, same location - just take the extra piece out for a better connection.

That brass post adapter comes with the batteries for people that are using automotive type cables.
You are not using automotive cable ends and don't want them on there without a good reason.

lc0338

Marc Kurth said:

Putting it as a question:  Why are you using the automotive posts on the batteries right now? 

You should just unscrew the brass "SAE automotive" adapter posts from the batteries. You don't want them there, they are working against you.

Once you have removed them, just attach your existing cable right to the battery, in the same threaded socket that the adapter post was screwed in. You will immediately that this gives you a much larger metal-to-metal contact area.

The female thread in the battery housing is 8mm. The thread where you are currently connected on top of the brass post is 8mm. 
Use the same bolt, the same cable, same location - just take the extra piece out for a better connection.

That brass post adapter comes with the batteries for people that are using automotive type cables.
You are not using automotive cable ends and don't want them on there without a good reason.

Using it that way because that's the way it was when I picked it up. I had purchased all the solar parts except the batteries. I live in Oklahoma and had a guy in Springfield Missouri fabricate the unit from my design and he installed all the parts and purchased the batteries at the last moment. I will investigate to see if the tapers will come off when I have the new inverter installed. If the adapters are removed it looks like a shorter bolt would be required but will see.

Marc Kurth

OK, that makes sense now!

I can assure you that the brass automotive post adapters are removable. They have their own 8mm stud on the bottom. They are removable specifically for the reason discussed. (I have put a LOT of Fullriver batteries on industrial/commercial/mobile systems)

The hardware looks stock, just as Fullriver normally ships. The stainless bolt on top is not as long as the post adapter - it only goes down about half way. So your bolt will not change. The batteries were designed with the same bolts/threads for interchangeability with and without the SAE post adapter.

Edit to add picture - I took this for you to see what I mean. This is a larger battery, but the concept is the same:

lc0338

Thanks Marc, I had no idea. Honestly though, the guy that put my solar system together was more on the solar grid end of things so I guess he had never worked with too many battery systems. I sure have found out a lot about my unit through this forum. Alway's good to find ways to make improvements

lc0338

Raj174 said:

Here's a better price, new, free shipping, and a Google trusted store.

https://www.universalmania.com/products/xantrex-freedom-sw3024-inverter-charger-3000w-24v?variant=26324533511&gclid=CNjQ6vDe0s4CFQkMaQodZkYCSA

This is the spec doc on the unit.

http://www.xantrex.com/documents/Inverter-Chargers/Freedom-SW-24V/DS20160505_FreedomSW24V.pdf

That must have been a one day sale. it is back to $1822 now. but still free shipping

lc0338

Hey Guy's,

Have a dumb question. When you order the xantrex freedom sw3024 is it necessary to order the control panel separate or is it possible to adjust the charge rate downward (from 75amp to 55amp) without it? It looks like the control panel is another $175 or so

Raj174

lc0338 said:

Raj174 said:

Here's a better price, new, free shipping, and a Google trusted store.

https://www.universalmania.com/products/xantrex-freedom-sw3024-inverter-charger-3000w-24v?variant=26324533511&gclid=CNjQ6vDe0s4CFQkMaQodZkYCSA

This is the spec doc on the unit.

http://www.xantrex.com/documents/Inverter-Chargers/Freedom-SW-24V/DS20160505_FreedomSW24V.pdf

That must have been a one day sale. it is back to $1822 now. but still free shipping

Just checked it out, and it's still 1726.27

Raj174

lc0338 said:

Hey Guy's,

Have a dumb question. When you order the xantrex freedom sw3024 is it necessary to order the control panel separate or is it possible to adjust the charge rate downward (from 75amp to 55amp) without it? It looks like the control panel is another $175 or so

I think this info is available at www.xantrex.com

vtmaps

lc0338 said:

When you order the xantrex freedom sw3024 is it necessary to order the control panel separate or is it possible to adjust the charge rate downward (from 75amp to 55amp) without it? It looks like the control panel is another $175 or so

All of the major inverter/charger manufacturers (Outback, Magnum, Schneider, etc) sell the controls separate.  And it's a very good thing!

I have my inverter in the garage, but my controls are in the house.  If controls were built-in to my inverter, I would have had to buy 2 sets of controls (the built-in and the remote).  Also, many folks stack several inverters to make split phase or three phase power... if each of the inverters had built-in controls, they would have had to buy several sets of controls.

You do need to control your inverter.  Buy the controls.  Exception, maybe... There is a trend toward network (computer) control of electronics.  I'm not too familiar with Schneider, but maybe you can control it with a laptop computer.

--vtMaps

Dave Angelini

lc0338 said:

Raj174 said:

Here's a better price, new, free shipping, and a Google trusted store.

https://www.universalmania.com/products/xantrex-freedom-sw3024-inverter-charger-3000w-24v?variant=26324533511&gclid=CNjQ6vDe0s4CFQkMaQodZkYCSA

This is the spec doc on the unit.

http://www.xantrex.com/documents/Inverter-Chargers/Freedom-SW-24V/DS20160505_FreedomSW24V.pdf

That must have been a one day sale. it is back to $1822 now. but still free shipping

From the store here you can get a

Schneider Electric Conext SW 4024 3,500 Watts, 24VDC Inverter/Charger for Split-phase 120/240 VAC

$1,495.00

Or the 2524 for $1250

lc0338

vtmaps said:

lc0338 said:

When you order the xantrex freedom sw3024 is it necessary to order the control panel separate or is it possible to adjust the charge rate downward (from 75amp to 55amp) without it? It looks like the control panel is another $175 or so

All of the major inverter/charger manufacturers (Outback, Magnum, Schneider, etc) sell the controls separate.  And it's a very good thing!

I have my inverter in the garage, but my controls are in the house.  If controls were built-in to my inverter, I would have had to buy 2 sets of controls (the built-in and the remote).  Also, many folks stack several inverters to make split phase or three phase power... if each of the inverters had built-in controls, they would have had to buy several sets of controls.

You do need to control your inverter.  Buy the controls.  Exception, maybe... There is a trend toward network (computer) control of electronics.  I'm not too familiar with Schneider, but maybe you can control it with a laptop computer.

--vtMaps

vtMaps, that makes sense. Thanks!!!

It looks like when advertising the inverter/charger it would be made a little more evident that the control panel needs to be ordered, if first time use, and give a part number. I could have overlooked it though.

lc0338

Well, Thanks to all for the input. I pulled the trigger and placed an order. Got an email a few minutes later from my credit card provider if I recognized these purchases. I had bought some gas earlier for my diesel truck so it was 50+ dollars and placed the order for the inverter/charger for $1930 and then there was one other transaction (at walmart) that was declined.... it turns out my wife went to walmart after work and tried to check out a little while after I placed the large inverter order and they declined HER card. I guess I will be spending the night in the dog house. I was going to keep this purchase quiet  

Xantrex 25' Network Cable for SCP Remote Panel × 1  - $29.68

Xantrex Xanbus System Control Panel (SCP) for Freedom SW2012 3012 × 1 - $174.45

Xantrex Freedom SW3024 Inverter Charger - 3000W - 24V × 1 -$1,726.27

shipping free
from universal mania

DRickey

Xantrex makes an SW 2024 (2000W continuous, I think 3000 peak), it's only about $300 cheaper but it will fill your needs. The big problem with the 12V system at those outputs is that 125 amps is a lot for that weight of batteries, and requires 2/0 cables to not have an issue with transmission losses even across comparatively short runs.

It's the kettle that's really the issue. Maybe look for one that runs at a lower wattage? 900 or so would be easy to work around. Might make more sense than trying to beef up a system that is otherwise working for you.

Edit: And then I read to the bottom and see you already pulled the trigger. Well, it should work fine for you, let us know.

lc0338

DRickey said:

Xantrex makes an SW 2024 (2000W continuous, I think 3000 peak), it's only about $300 cheaper but it will fill your needs. The big problem with the 12V system at those outputs is that 125 amps is a lot for that weight of batteries, and requires 2/0 cables to not have an issue with transmission losses even across comparatively short runs.

It's the kettle that's really the issue. Maybe look for one that runs at a lower wattage? 900 or so would be easy to work around. Might make more sense than trying to beef up a system that is otherwise working for you.

Edit: And then I read to the bottom and see you already pulled the trigger. Well, it should work fine for you, let us know.

Yeah, there was a lot of posts to read through on this thread and I have been wandering like a lost soul tying to make up my mind... stay 12 volt or jump to 24v... buy an inverter/charger or stay with separate systems Inverter and separate charger.... It made my head hurt. I kinda believe if I had had a good 2000 watt inverter like a xantrex or another with similar higher quality with a little higher temperature window (140 instead of 104 deg F) to begin with, I would probably would not have had an  issue to begin with. Since I was going to have to spend some money (to replace that samlex 2000)  I thought it best to up the voltage and kill 2 birds with one stone. Only thing I'm wondering now since my panels will need to be changed to series.... if any partial shade will knock my electric generation down enough to be noticeable.

Raj174

Any shading at all on a series string can cause a considerable drop in PV output. 

DRickey

You'll probably take less of a hit running them in parallel at a less than ideal voltage for the MPPT controller than in series for only two panels. I ran my pair of 235W both ways, with similar mobility making it difficult to control shading, and found that overall, I was better with parallel.

The MPPT is going to be stepping it down either way, it's just not quite as efficient with a single panel's worth of voltage. And in the long run, you'll probably make up in the inverter side what you're losing on the charging.

lc0338

DRickey said:

You'll probably take less of a hit running them in parallel at a less than ideal voltage for the MPPT controller than in series for only two panels. I ran my pair of 235W both ways, with similar mobility making it difficult to control shading, and found that overall, I was better with parallel.

The MPPT is going to be stepping it down either way, it's just not quite as efficient with a single panel's worth of voltage. And in the long run, you'll probably make up in the inverter side what you're losing on the charging.

Can we have a little more discussion here. I thought I had 12 volt panels and by going to a 24 volt battery bank I would "have to" have them hooked in series? Here is the info on my panels. I have 2ea. I want to make sure I don't screw up and damage something.

Raj174

What you have are called grid tie panels, and you definitely need 2 in series to charge a 24 volt battery with a MPPT controller.

DRickey

I'm not sure what the issue is, other than that at a Vmp of 30.9 he's right on the margins for equalizing batteries. But he can plugin and equalize with the charger/inverter every few months to fill that gap, which is better than having his charging drop through the floor because a whip antenna or power line is shading a panel.

Raj174

Try it both ways, it's just a wiring configuration change. If the parallel config doesn't work for you, reconfigure.

lc0338

on fullriver agm battery website it states that if batteries are properly charged they do not require equalization: here is a statement i copied and pasted:

Refresh Charge
If Fullriver batteries are properly charged they should never require an equalizing charge. If they were not properly charged and there is a decrease in capacity, recharge the batteries and make sure they complete the entire charge cycle. If the batteries are stored for extended periods of time, recharge them as follows:

DRickey

Yeah, as I understand it AGM batteries don't need equalizing, in some cases it can actually damage them. In liquid-electrolyte cells it is used to stir the electrolyte and remove impurities from the plates.

BB.

AGMs, while they are not supposed to need equalization--Some  "equalization" can be done by extended charging times at normal absorb voltage.

Here it is--A "conditioning" charge for Concorde:
http://www.concordebattery.com/Chairman_Technical_Manual.pdf

Note that other brands of AGM batteries may not tolerate this high of charging/recovery voltage.

-Bill

vtmaps

BB. said:

AGMs, while they are not supposed to need equalization--Some  "equalization" can be done by extended charging times at normal absorb voltage.  Here it is--A "conditioning" charge for Concorde:

But the 2.6 VPC that Concorde recommends for conditioning is higher than normal absorb voltage.

By the way, the popular Iota battery chargers are sometimes used (on the grid) to hold batteries at float voltage.  When used that way, they do an automatic weekly "equalization".   The "equalization" is really just a normal absorb cycle at absorb voltage.  Its purpose is to break up the stratification that occurs during float in flooded cells.

--vtMaps

BB.

AGM batteries can/do get unbalanced over time (much less than flooded cell batteries). And doing longer than normal absorb charging once every 6-12 months has been a recommendation (by at least some folks) for a number of years now.

The AGM conditioning to "recover capacity" with higher than normal (absorb) voltage is (as far as I know) for Concorde batteries only.

-Bill

Marc Kurth

@BB: I completely agree on both points, Bill.

Doing an occasional extended absorb run, really helps bring the cells back in line with each other. I am also convinced that getting a 10-12 hour float charge occasionally, really helps the process.

I have recovered a huge amount of storage capacity, from abused Concorde batteries via equalization at 2.6v per cell for 8 hours, per their recommendation.

One recommended method to help recover from extended deep discharge sounds extreme, but has worked well to breathe new life into batteries that appeared ready for recycling:

Charge at a constant current of 5% of the the C20 rating, until voltage rises to 2.6v per cell. Then continue at the same current for another 4 hours, which may require as high as 3.0v per cell. Terminate and wait for cool down if battery exceeds 130 F. This process should only be performed starting from a fully discharged condition.

All AGM batteries are not the same.

Marc

lc0338

Well, have received the xantrex 3000 watt 24 volt inverter charger. Hoping to get it installed within the next few days. I'll get a picture once everything is installed. Going to have to do some re-arranging inside the cabinet due to the larger size inverter.

lc0338

just a quick question for those familiar with the xantrex 3024 inverter charger.

in my solar generator I have a battery disconnect switch to turn on/off the inverter. It does not look like this new inverter charger will allow that. Is buying the remote the only option to turn on/off other than the remote. I would like to turn it on/off without taking  the front door off. I plan to call xantrex cust support but they are on pacific time and its early here and also sometimes the wait time is long. Thanks for any quick response.