The upgradable system problem

[12VoltInstalls]

You can't go to 1200W until you add a second battery.

Unless the SCC/AIO allows for configuring a lower charge rate which I think the 230V MPP Solar and Growatt units do.
At peak sun irradiation NO you will not get the full advantages of high watt solar arrays, but you will get usable increased output early and later in the daylight period.

 

[rmaddy]

Unless the SCC/AIO allows for configuring a lower charge rate which I think the 230V MPP Solar and Growatt units do.
At peak sun irradiation NO you will not get the full advantages of high watt solar arrays, but you will get usable increased output early and later in the daylight period.

Very true. I didn't intend to state that you were physically limited to 600W/1200W. In my head I was thinking of usable watts actually coming in but I didn't make that clear.

 

[Begginer7]

As long as they're not going to get below freezing, the Chins/Ampertime/Zooms are a great bang for the buck. They save money by going with a plastic case instead of steel and not having as fancy a BMS with low temp cutoff, which seems to be about a $300 feature for some reason.

Ampertime gave me a quote for 12V 100ah 637.99€ 24V 100Ah: 1559.99€, as they are shipping from within the EU there should not be large additiinal taxes, however SOK 12v 100ah is 630 €, seems SOK is cheaper and better.

 

[12VoltInstalls]

And two is EU$1260 for 100Ah 24V
That’s pretty easy to decide!

 

[Rednecktek]

Ampertime gave me a quote for 12V 100ah 637.99€ 24V 100Ah: 1559.99€, as they are shipping from within the EU there should not be large additiinal taxes, however SOK 12v 100ah is 630 €, seems SOK is cheaper and better.

Wow! That's more than double what we pay in the states! Yeah, at that markup the SOK are a much better option. I was expecting the prices of the 12v 100Ah and 24v 100Ah would be comparable.

 

[HighTechLab]

So does that mean that if we discharge and charge once a day then Ampertime will last 1500/365= 4.1 years while sok 2500/365= 6.8 years,? maybe this is the reason for the guarantee difference?

SOK has 2500 ADDITIONAL cycles, so you would get 6.8 years MORE, so total over 10 years. This is why they have a much longer warranty (7 year from factory)

 

[Begginer7]

Today my expectation of building an upgradable system suffered a wake up call of sorts, a local expert told me that adding batteries to an existing batery bank after 6 months will cause the older batteries to behave like a resistance and pose a fire hazard, is this correct?

 

[sunshine_eggo]

Today my expectation of building an upgradable system suffered a wake up call of sorts, a local expert told me that adding batteries to an existing batery bank after 6 months will cause the older batteries to behave like a resistance and pose a fire hazard, is this correct?

Wow.

Please ask him how adding to batteries that are 5 months 28 days old are fine, but when adding to batteries that are 6 months and 1 day old it's suddenly a fire hazard.

They are an alarmist a$$. The use of "expert" in their description is totally misplaced.

Is it ideal? No. Is it a fire hazard? Only if something is already HORRIBLY wrong with the 6 month old batteries, and they're going to be a fire hazard even if you don't add more batteries.

The newer batteries will tend to take slightly more than their fair share of load/charging due to their lower internal resistance, thus you're actually reducing the stress on the older batteries.

It is important that you engage in best practices when wiring your bank together. Ref Victron Wiring Unlimited.

There is a greater concern if adding in SERIES. It is very important that series elements be as close to identical as possible.

In any case, if you use a clamp ammeter to confirm that all batteries in a bank are operating within their specifications, there is essentially nothing to worry about.

 

[12VoltInstalls]

adding batteries to an existing batery bank after 6 months will cause the older batteries to behave like a resistance and pose a fire hazard, is this correct?

Good thing my batteries didn’t get that memo.
Counting a couple that got stolen I’ve added newer batteries three times. Today when the SCC went into float 13.8V, my batteries were still 14.2 from a couple hours earlier.

Don’t sweat the mindless people

 

[WYtreasure]

Today my expectation of building an upgradable system suffered a wake up call of sorts, a local expert told me that adding batteries to an existing batery bank after 6 months will cause the older batteries to behave like a resistance and pose a fire hazard, is this correct?

Sounds like your "expert" likes the "sensational" to make a point. I have seen here on the forum that adding batteries some time in the future is not a good idea. I believe a workaround is if the newly added batteries are powered by a separate SCC, I could be wrong.

 

[Begginer7]

Good thing my batteries didn’t get that memo.
Counting a couple that got stolen I’ve added newer batteries three times. Today when the SCC went into float 13.8V, my batteries were still 14.2 from a couple hours earlier.

Don’t sweat the mindless people

What is your setup? In series or parallel?

 

[12VoltInstalls]

What is your setup? In series or parallel?

I have two banks of four with balanced/equal cable lengths Four in parallel then paralleled together at a terminal stud before being cabled inside to busbars.

Good thing my batteries didn’t get that memo.
Counting a couple that got stolen I’ve added newer batteries three times

In all fairness to you, adding new batteries to older batteries and/or mixing batteries of different ages is NOT best practice. This can weaken or shorten the life of the new batteries, or even damage them severely if the batteries have greatly reduced

I’ve done it with my eyes open in my situation.

The six months was what bothered my head and made me post.

 

[Begginer7]

Today a vendor of AiO inverters told me that I can add modular Scc afterwards to increase my Solar array and batery bank, is this correct?

 

[sunshine_eggo]

Multiple MPPT is not uncommon. Many do it to achieve the needed charging amps, for redundancy, or for using different panels that won't play well on the same MPPT.

It's just like adding another charger to a battery.

 

[Rednecktek]

Today a vendor of AiO inverters told me that I can add modular Scc afterwards to increase my Solar array and batery bank, is this correct?

Yup, there's a whole sticky about Charging from Multiple Sources, it's not uncommon at all. Especially when you're putting in LARGE arrays and can't find a 300a rated MPPT controller.

 

[Begginer7]

Multiple MPPT is not uncommon. Many do it to achieve the needed charging amps, for redundancy, or for using different panels that won't play well on the same MPPT.

It's just like adding another charger to a battery.

So it does not matter that the first Scc is one that is incorporated in the all in one inverter? I could get first a Growatt inverter with the Scc and afterwards I could add an Epever Scc?

 

[sunshine_eggo]

So it does not matter that the first Scc is one that is incorporated in the all in one inverter?

It does not.

I could get first a Growatt inverter with the Scc and afterwards I could add an Epever Scc?

Yes.

 

[sunshine_eggo]

Yup, there's a whole sticky about Charging from Multiple Sources, it's not uncommon at all. Especially when you're putting in LARGE arrays and can't find a 300a rated MPPT controller.

Charging from multiple sources

One can have as many independent charging sources running concurrently as they like provided they are programmed properly for the voltage of one's battery bank. Examples (some or all at once, even multiples of a single type, different brands, etc.): Solar PV via MPPT Solar PV via PWM AC-DC...

diysolarforum.com

 

[Begginer7]

It does not.



Yes.

This is such a relief, its the ideal setup then because the AIO inverters come with large inverters but small Sccs, for example 24V. 3k inverter with 60A Scc, you are restricted to about 1500W of Solar array, but with such an array is difficult to use the 3000w potential of the inverter.

 

[WYtreasure]

This is such a relief, its the ideal setup then because the AIO inverters come with large inverters but small Sccs, for example 24V. 3k inverter with 60A Scc, you are restricted to about 1500W of Solar array, but with such an array is difficult to use the 3000w potential of the inverter.

So Beginner7, it's pretty cool how you can hang out here and learn about "almost everything under the SUN". Don't you agree?