Help updating old system

[nostaW]

Hello,

I bought an off grid home about a year ago and am interested in updating and upgrading the current system, which is 10 - 12 years old. I am new to solar, so not sure what all my equipment even is. But as I understand it...
*My current set up*
6 - evergreen solar 210w panels
6 - LG 300w panels
16 - 468ah 6v rolls s605 batteries
1- xentrex charge controller
1- midnite classic charge controller
- MagnaSine inverter?
- midnite control panel? MNDC250

Not exactly sure what the MagnaS unit is or the midnite control panel? One I assume is an Inverter and the other maybe battery monitoring system?

Either way, the main short coming I've learned with this set up, is that my batteries seem to drain quite fast. I suspect they may be at the end of their life being 10+ year old lead acid batteries. Also I feel like my PV set up is a little under sized.

*The upgrade*
So I'm considering upgrading from lead acid to lifepo4 eg4 server rack batteries And adding some new panels to my PV array.
However, can I simply remove my old lead acid batteries and install the new eg4 batteries with minimal to no changes? Or do I need a total system rework?

Also to add more PV panels will I need more charge controllers? More inverter? How do I figure this out?

If it helps, I figured my house on a heavy usage day will consume around 34kwh

Thanks in advance for any help!

 

[googdot]

The Midnite Control Panel is the white box in the bottom right of your picture. It is simply a DC breaker box and meant to keep things tidy and accessible.

Product - MidNite Solar

MidNite Solar Product Page.

www.midnitesolar.com

 

[MisterSandals]

Not exactly sure what the MagnaS unit is

It takes DC power from the batteries (and solar if your Xantrex and Midnite SCCs are producing) and converts it to household current. If you have a model number (something like PAE4048), its easy to see if it outputs 120V or 240V. It feeds the breaker panel just below it).

I am guessing your batteries are 6V each and wired in series for 48V battery bank. If there are any amp hour numbers on the red batteries, we can figure out your battery size (will be that Ah rating at 48V) in watt hours (Ah x V).

Looks like there is a switch for generator or utility input in lower left. The MagnaSine can accept power from either one, but not both.

6 panels provide power to the Xantrex solar charge controller and 6 panels to the Midnite solar charge controller.

Nice setup. If your batteries are storing and providing enough power, its current enough and high quality kit.

What are you seeing or wanting that you want to upgrade?

 

[42OhmsPA]

That's a solid setup with tier 1 components.
If your comfortable wiring the lead acid batteries in series you should consider making your own lifepo4 packs... You could save a pile of cash.
You should be able to easily change your current charge profiles to be better suited for lifepo4.
If you provide the models of your charge controllers we can help best layout your solar strings.
I'd consider selling the 210w panels and adding new panels in there place.

 

[nostaW]

It takes DC power from the batteries (and solar if your Xantrex and Midnite SCCs are producing) and converts it to household current. If you have a model number (something like PAE4048), its easy to see if it outputs 120V or 240V. It feeds the breaker panel just below it).

I am guessing your batteries are 6V each and wired in series for 48V battery bank. If there are any amp hour numbers on the red batteries, we can figure out your battery size (will be that Ah rating at 48V) in watt hours (Ah x V).

Looks like there is a switch for generator or utility input in lower left. The MagnaSine can accept power from either one, but not both.

6 panels provide power to the Xantrex solar charge controller and 6 panels to the Midnite solar charge controller.

Nice setup. If your batteries are storing and providing enough power, its current enough and high quality kit.

What are you seeing or wanting that you want to upgrade?

It takes DC power from the batteries (and solar if your Xantrex and Midnite SCCs are producing) and converts it to household current. If you have a model number (something like PAE4048), its easy to see if it outputs 120V or 240V. It feeds the breaker panel just below it).

I am guessing your batteries are 6V each and wired in series for 48V battery bank. If there are any amp hour numbers on the red batteries, we can figure out your battery size (will be that Ah rating at 48V) in watt hours (Ah x V).

Looks like there is a switch for generator or utility input in lower left. The MagnaSine can accept power from either one, but not both.

6 panels provide power to the Xantrex solar charge controller and 6 panels to the Midnite solar charge controller.

Nice setup. If your batteries are storing and providing enough power, its current enough and high quality kit.

What are you seeing or wanting that you want to upgrade?

Yes, system is 48v, batteries are 6v and I believe 468ah.

The switch is a mystery to me really. I bought the house with the system installed. Hence my limited knowledge. I do however run a honda 7500eu generator when needed. There is a plug In outside for it.

My concern is that these batteries are discharging faster than I'd expect, or not charging fully. Even if I use very little power, on a day without sun, the batteries will run down below 48v in a few hours.

Another observation I've made is on sunny days, when the panels are producing a strong charge. There is a bubbling/hissing sound that comes from the batteries. Is that normal?

 

[MisterSandals]

Another observation I've made is on sunny days, when the panels are producing a strong charge. There is a bubbling/hissing sound that comes from the batteries. Is that normal?

Have you checked the fluid levels lately?

Do any of the batteries get warm when you notice this?

 

[schmism]

what maintenance do you do on your FLA? They need weekly water checks, and like monthly SG checks/corrections.

The sizeing is typical of systems from 10 years ago when panel costs were like $3/watt when today its .50/w You have ONLY have 3000 panel watts which likely pulls in less than 2500 in the summer.

Its likely that your power needs (wants) are significantly larger than the ~12kw/day your current system can provide.

Additional panels and a newer (or addtional) SCC that supports higher string voltages would be were I start.

 

[nostaW]

Have you checked the fluid levels lately?

Do any of the batteries get warm when you notice this?

I check the fluid regularly and keep them all topped off.

I haven't really paid attention to see if the batteries get warm when I hear the noise. What could that mean if they are?

 

[nostaW]

what maintenance do you do on your FLA? They need weekly water checks, and like monthly SG checks/corrections.

The sizeing is typical of systems from 10 years ago when panel costs were like $3/watt when today its .50/w You have ONLY have 3000 panel watts which likely pulls in less than 2500 in the summer.

Its likely that your power needs (wants) are significantly larger than the ~12kw/day your current system can provide.

Additional panels and a newer (or addtional) SCC that supports higher string voltages would be were I start.

I do check the water in the batteries every couple weeks and top them off as needed. As far as SG corrections? I don't know what that means.

I do agree that additional panels would be a good addition to my setup. I've been looking at buying some Canadian solar 400w panels to get my PV power around 10kw

 

[Mattb4]

Not a fan of using grease to protect terminals especially in the large amounts shown in your photo. It can hide a poor connection and even contribute towards one if it gets between lug and post. There are various sprays and dielectric greases that can be used if corrosion is a on going issue. Most FLA terminal corrosion will be due to a cracked seal between case and post. Fixed place installations without the vibration of a car or boat are less likely to suffer leakage problems.

As to your supply needs. If your loading requirements dictate 34kWh/day than obviously your supply must produce it. Note: batteries are not a power supply. So how much PV does it take? Let's guess you days insolation is 4-5 hours. 34kWh/5h=6.8kW or 6800w worth of panels. but that is only a good number during a good sunny day and at the right season. You will have to allow for not good days and less production in Winter.

I do not know if your batteries are good or bad. It is entirely possible that you are drawing from them at a much higher rate than the system was designed to accommodate.

My suggestion is to first figure out how much loads you have and than work towards what you need to supply them.

 

[MisterSandals]

I suspect they may be at the end of their life being 10+ year old lead acid batteries.

After 10+ years they are likely getting sleepy.

When your batteries are low, if you can measure the resting voltage (not charging or discharging), check the voltage of each battery. If you have some that are significantly below 6V (also likely to be getting warm when you hear boiling/gurgling), those are the worst and likely ready to be retired. Since all your batteries are in series, there is no option to add a couple new ones to an old bank.

 

[nostaW]

After 10+ years they are likely getting sleepy.

When your batteries are low, if you can measure the resting voltage (not charging or discharging), check the voltage of each battery. If you have some that are significantly below 6V (also likely to be getting warm when you hear boiling/gurgling), those are the worst and likely ready to be retired. Since all your batteries are in series, there is no option to add a couple new ones to an old bank.

I did have someone test my batteries shortly after I bought the place in December. All my batteries tested just above 6v. He also tested the individual cells, and wrote down some other numbers that I dont understand. I'll attach the sheet with numbers he wrote down.

 

[cdherman]

Also, for the OP, your old panels are a) degraded and b) older tech. If you have limitless roof space, then you *could* add panels as you suggest. But if you are contemplating really covering your 34 kwh load, you are going to be upgrading a lot of things. Might be best to replace the old panels for ones that take less space and can integrate better with the expansion panels.

I am a solar old timer, but also out of practice so my knowledge is at times questionable. But I am proud my now 14 year old system has seen essentially zero down time. Grid tie is more stable though, so no fair comparison.

Also -- can you share just where that 34 kwh is going? You might be due a new AC or perhaps you should consider geo or 2nd gen heat pump. Just that 34 a is a lot. Looks like the original owners got by on less or ran the generator a lot........

 

[JunglePower]

Yes, system is 48v, batteries are 6v and I believe 468ah.

The switch is a mystery to me really. I bought the house with the system installed. Hence my limited knowledge. I do however run a honda 7500eu generator when needed. There is a plug In outside for it.

My concern is that these batteries are discharging faster than I'd expect, or not charging fully. Even if I use very little power, on a day without sun, the batteries will run down below 48v in a few hours.

Another observation I've made is on sunny days, when the panels are producing a strong charge. There is a bubbling/hissing sound that comes from the batteries. Is that normal?

Your system is similar to what was in the house I bought, including the Rolls batteries (they and all the other components were over 20yo).
After dealing with the batteries for almost a year, SG, constant dist water, cleaning equalizing, I gave them to a friend and put in 8 BB1002s and things improved.
I then added four "modern" 400w PEIMAR panels and another Morningstar controller just for them. Unbelievable difference, out performing the ancient 18 100w poly Kyocera panels by triple output. Haven't run the genny since the upgrade, even with two, three days of clouds and rain.

 

[nostaW]

Also, for the OP, your old panels are a) degraded and b) older tech. If you have limitless roof space, then you *could* add panels as you suggest. But if you are contemplating really covering your 34 kwh load, you are going to be upgrading a lot of things. Might be best to replace the old panels for ones that take less space and can integrate better with the expansion panels.

I am a solar old timer, but also out of practice so my knowledge is at times questionable. But I am proud my now 14 year old system has seen essentially zero down time. Grid tie is more stable though, so no fair comparison.

Also -- can you share just where that 34 kwh is going? You might be due a new AC or perhaps you should consider geo or 2nd gen heat pump. Just that 34 a is a lot. Looks like the original owners got by on less or ran the generator a lot........

34kwh is kind of a guess. I did fill out a load analysis worksheet, but I'm not 100% sure what the load is for all my utilities and devices in the house. So I went with a high estimate. However I do live in MN, so the 34kwh is assuming running two boilers (one for house, one for garage) and the circulation pumps (5 in total) for my radiant heat during winter. Summer months I use far less power and rarely have to run the generator, but during the winter months I have to run my generator every day.

 

[nostaW]

So, from all of your replies, It sounds like I should start by adding panels to my system and keep everything else the way it is.

It seems it's not worth spending the extra money to swap out the FLA batteries for Lifepo4 just yet.

Thanks for all your responses! I'm sure I'll have more questions in the future.

 

[cdherman]

34kwh is kind of a guess. I did fill out a load analysis worksheet, but I'm not 100% sure what the load is for all my utilities and devices in the house. So I went with a high estimate. However I do live in MN, so the 34kwh is assuming running two boilers (one for house, one for garage) and the circulation pumps (5 in total) for my radiant heat during winter. Summer months I use far less power and rarely have to run the generator, but during the winter months I have to run my generator every day.

What kind of circulators do you have? Look intro grundfos Alpha if you don't have them already. Modern variable speed circulators can take far less power. The hydronic world is also talking more about how to get by with less pumps, but 5 doesn't sound so egregious. But your main pumps that run all the time should possibly be upgraded.

 

[saggys]

I would also test the specific gravity of all your batteries, this will let you know if you are getting the full charge they need.

Nice solid "old school" set up you have there.

I am currently upgrading my "old school " set up also, but my panels were even older than yours, all 12 volt battery panels.