Need assistance

 

If you buy a lithium lifepo4 BATTERY say this year, March, how long can you wait to add the second one, or even the third to increase power.

 

Thanks

 

 

7 hours ago, Furlongs said:

Need assistance

 

If you buy a lithium lifepo4 BATTERY say this year, March, how long can you wait to add the second one, or even the third to increase power.

 

Thanks

 

 

The answer is easy, you should wait no longer than what your wallet allows for. 

Or put differently, add a 2nd or 3rd battery as soon  as possible.

Seriously though,  not sure what you are trying to ask

6 minutes ago, I84RiS said:

The answer is easy, you should wait no longer than what your wallet allows for. 

Or put differently, add a 2nd or 3rd battery as soon  as possible.

Seriously though,  not sure what you are trying to ask

Rephrase: can I wait a year before adding second or third?

11 minutes ago, Furlongs said:

Rephrase: can I wait a year before adding second or third?

Yes. Between purchasing my 1st Pylon and my 5th was probably around 2 years. You can add batteries whenever you want (can afford)

2 minutes ago, Furlongs said:

Rephrase: can I wait a year before adding second or third?

In theory yes, you generally will be able to add a new battery to an existing LiFePO4 battery bank at any time.

In reality it is often not that easy as you want to make sure that your different batteries in your bank are consistent in terms of the number of cells in each battery, the cell manufacturer used in each battery as well as the BMS hardware and BMS firmware used in each battery.

Often when purchasing the same battery model from the same manufacturer 12 months apart does not guarantee that the these items are similar or even compatible.

It does not mean that it won't work, but it might require some manual tweaking here and there.

If you want peace of mind in terms of future upgrade path and compatibility amongst different battery generations then Pylontech is the only real choice as they have a solid history of ensuring compatibility between their batteries.

I use 3 batteries from the same manufacturer, all purchased at different dates. Between these 3 batteries the manufacturer changed their cell supplier and changed their BMS supplier. So the 3 batteries look exactly the same but that is where the similarities end. 

They bank does work, but it is not a plug and play solution that can be left to its own. 

2 hours ago, I84RiS said:

In theory yes, you generally will be able to add a new battery to an existing LiFePO4 battery bank at any time.

In reality it is often not that easy as you want to make sure that your different batteries in your bank are consistent in terms of the number of cells in each battery, the cell manufacturer used in each battery as well as the BMS hardware and BMS firmware used in each battery.

Often when purchasing the same battery model from the same manufacturer 12 months apart does not guarantee that the these items are similar or even compatible.

It does not mean that it won't work, but it might require some manual tweaking here and there.

If you want peace of mind in terms of future upgrade path and compatibility amongst different battery generations then Pylontech is the only real choice as they have a solid history of ensuring compatibility between their batteries.

I use 3 batteries from the same manufacturer, all purchased at different dates. Between these 3 batteries the manufacturer changed their cell supplier and changed their BMS supplier. So the 3 batteries look exactly the same but that is where the similarities end. 

They bank does work, but it is not a plug and play solution that can be left to its own. 

Simplified:

 

I bought Esener25.6v this March, I want to add another one but no cash now.

 

Can I add it March next year?

 

What are the do's and don'ts,?

Will it be ok if I wait this period?

 

I am using 3kva Growatt 24v currently with no panels.

Thanks 

 

Short answer yes. Long answer: if the manufacturer changes the cell layout or the BMS or just doesn't exist anymore, you'll be in a difficult spot

Perhaps stupid questions, but....

1). Additionally, should the capacity of new battery also match the existing batteries? For instance if I have 2.x 5.12kWh 100Ah batteries can I add a 200Ah battery or 50Ah battery? Moreover, what about matching C ratings?

2). Can batteries with different state of health be matched? In which case, should the ones with lower SOH rather be slaves?

3). Is it better to make the newest battery the master? (guess question overlaps question 2 a bit).

 

Edited March 4, 20233 yr by jgdt

3 minutes ago, jgdt said:

Perhaps stupid questions, but....

1). Additionally, should the capacity of new battery also match the existing batteries? For instance if I have 2.x 5.12kWh 100Ah batteries can I add a 200Ah battery or 50Ah battery? Moreover, what about matching C ratings?

2). Can batteries with different state of health be matched? In which case, should the ones with lower SOH rather be slaves?

3). Is it better to make the newest battery the master? (guess question overlaps question 2 a bit).

 

Always better to put the newer battery as the main(master) and the others as the secondary. Most battery manufacturers don't allow mixing sizes but I know Pylontech does. So with most batteries you have to get the same size, brand and model

4 hours ago, madness_za said:

or just doesn't exist anymore, you'll be in a difficult spot

Sigh, this is stressing me out. Guess that's why one need to fork out the additional money in the beginning to get a good manufacturer/make/model. Even if the manufacturer is solid, in SA one is still subject to whatever gets imported when and the general availability

I wanted to do this with a SHOTO 5100kwh battery I bought in November

The same importer who sold the first one said “don’t”.  He would not elaborate except to say my warranty would be void

On 2023/03/03 at 2:42 PM, Furlongs said:

how long can you wait to add the second one, or even the third to increase power.

First of all, with additional batteries you do not increase power but energy storage capacity. It's like increasing the fuel tank capacity on your car, it does not increase the power of the engine. The power is limited by your inverter.

Second, do it any time as soon as possible. The more battery capacity the better. But there should be no problem by doing it later.

I added a fourth pack Leoch TB48100 from Averge 6 months after the others. Although the product identification has not changed it appears that there are some internal changes (improvements). The BMS reports 103.8 Ah capacity compared to 100Ah of the others. Then it appears that its internal resistance is significantly lower than on the older ones. I installed it at the end of the row with the longest leads, yet it draws the highest current of them all in charge and on discharge. It appears that they improved the cell manufacturing. But so what? That does not present any problem. Yes, the new one charges faster and reaches full charge earlier than the others, but then the others catch up before the bank reaches bulk charge voltage setting.

How does this equalization work? The SOC is characterized by the battery's internal voltage. As the battery reaches full SOC its internal voltage reaches that specific value. The charge current however is determined by the difference between terminal voltage and internal voltage and the internal resistance (Ohms law). If one battery has higher SOC, its internal voltage is higher than the others, its difference to the terminal voltage smaller, thus the current lower. In extreme situation at full charge the difference goes to zero, thus zero current while the others still charge.

19 hours ago, chrisc said:

 He would not elaborate except to say my warranty would be void

Some supplier use just any pretext to flee guaranty reliability. I suspect the ones that do not know what they are dealing with.

2 hours ago, Beat said:

First of all, with additional batteries you do not increase power but energy storage capacity. It's like increasing the fuel tank capacity on your car, it does not increase the power of the engine. The power is limited by your inverter.

 

That's not correct. For example a pylon US3000C will limit its discharge and charge at 37A. Pretty well every inverter is rated above that. Yes it's correct when, say you have 3 x US3000C and the inverter is 100A and you add a 4th battery.

28 minutes ago, Tinbum said:

That's not correct. For example a pylon US3000C will limit its discharge and charge at 37A. Pretty well every inverter is rated above that.

Well, yes you are right for the cases where the battery is undersized with respect to the inverter. But I assumed that people do match battery and inverter sizes to start with.

Edited March 5, 20233 yr by Beat

5 minutes ago, Beat said:

Well, yes you are right for the cases where the battery is undersized with respect to the inverter. But I assumed that people do match battery and inverter sizes to start with.

No, I think that the package combo deals you see around could be leading to some people buying an under-sized battery because they don't know better. It's easy to slap together a 5kW inverter and a 5kWh 0.5C battery to make the kit more affordable, even if it might not meet the buyer's expectations.