Guys, these are th recommended charging voltages of my Quanta and Sinergy 200ah batteries.

Is it advisable to use both a 12v inverter system connected in parallel? The inverter has a charge voltage of about 14.5v

If no, please what are my options?

adrusa:


1. If your current PV setup can adequately charge your lead acid battery, it will be sufficient for lithium of similar capacity. Lithium is in fact a bit more efficient in charging, so it will even take a little less.

2. Lithium will perform better in all ramifications.

Thanks for your response.

Please can the second answer have an empirical example?

odimbannamdi:
Guys, these are th recommended charging voltages of my Quanta and Sinergy 200ah batteries.

Is it advisable to use both a 12v inverter system connected in parallel? The inverter has a charge voltage of about 14.5v

If no, please what are my options?

First and foremost, you can't use the inverter with the quanta as the charging current is too high for it, but it will work perfectly for the synergy.
Based on the above, I have 3 suggestions, first is to swap ur quanta for another battery model with the same chemistry as the synergy as in the same float and absorb ratings. You either sell the quanta and buy what u want or do a direct swap.

Secondly, u could create 2 banks with the inverter charging the synergy while you get a suoer digital battery charger that maxes out at 13.8v float and 13.5v absorb to charge the quanta independently; then use a battery switch to alternate between both, with the quanta always serving as ur back up bank while the synergy acts as the main bank.

Third would be tedious but worth considering, you can get an inverter with adjustable charge and cutoff inputs, using a battery switch alternate between the two and adjust the charge and cutoff as desired depending on the battery u're using.....

Just my 2 kobo..... Cheers

IYGEAL:


Thanks for your response.

Please can the second answer have an empirical example?

Charge and discharge efficiency of lithium is almost perfect; you get what you put in... attached is a full 14.3kwh LFP, notice the accuracy of the charge and discharge figures 20kwh (I did about 6kwh to full on BMV initially) is the difference and that has always been what I get at every cycle. In LA the difference will usually very and can be very significant in some cases

ojeysky:


Charge and discharge efficiency of lithium is almost perfect; you get what you put in... attached is a full 14.3kwh LFP, notice the accuracy of the charge and discharge figures 20kwh (I did about 6kwh to full on BMV initially) is the difference and that has always been what I get at every cycle. In LA the difference will usually very and can be very significant in some cases

Interesting. Thanks a bunch.

A DIY guy is proposing to arrange a 200AH 12v LFP for me. And, considering the prevalent prices, I would say he's doing it on the cheap.

I wasn't sure if my 600W PV would be suitable to charge it until now. My scepticism was due to the massive PV you guys using LFP are amassing for your arrangements here.

I think this is to charge the battery faster and use the PV to power your loads so long as the sun allows?

Your CC appears to draw more power from PV than the capacity of the PV. While charging and simultaneously using my 200AH 12V quanta battery, the CC draws about 300+Watts from the 600W PV early in the morning, and about 150W later in the day, even when the sun would be said to be at peak.

IYGEAL:


Interesting. Thanks a bunch.

A DIY guy is proposing to arrange a 200AH 12v LFP for me. And, considering the prevalent prices, I would say he's doing it on the cheap.

I wasn't sure if my 600W PV would be suitable to charge it until now. My scepticism was due to the massive PV you guys using LFP are amassing for your arrangements here.

I think this is to charge the battery faster and use the PV to power your loads so long as the sun allows?

Your CC appears to draw more power from PV than the capacity of the PV. While charging and simultaneously using my 200AH 12V quanta battery, the CC draws about 300+Watts from the 600W PV early in the morning, and about 150W later in the day, even when the sun would be said to be at peak.

Even 100w will charge it, but what is important is for how long. Since you have 600w PV, let's assume you are able to achieve 400w average harvest. That is 400÷12 which makes it about 33A charge rate @12v. 200÷33 will give you the number of hours it will take before battery gets full from empty.

NB: Those are theatrical calculations charge time can be +/- 60min

ojeysky:


Even 100w will charge it, but what is important is for how long. Since you have 600w PV, let's assume you are able to achieve 400w average harvest. That is 400÷12 which makes it about 33A charge rate @12v. 200÷33 will give you the number of hours it will take before battery gets full from empty.

NB: Those are theatrical calculations charge time can be +/- 60min

Thank you

saint2ace:


First and foremost, you can't use the inverter with the quanta as the charging current is too high for it, but it will work perfectly for the synergy.
Based on the above, I have 3 suggestions, first is to swap ur quanta for another battery model with the same chemistry as the synergy as in the same float and absorb ratings. You either sell the quanta and buy what u want or do a direct swap.

Secondly, u could create 2 banks with the inverter charging the synergy while you get a suoer digital battery charger that maxes out at 13.8v float and 13.5v absorb to charge the quanta independently; then use a battery switch to alternate between both, with the quanta always serving as ur back up bank while the synergy acts as the main bank.

Third would be tedious but worth considering, you can get an inverter with adjustable charge and cutoff inputs, using a battery switch alternate between the two and adjust the charge and cutoff as desired depending on the battery u're using.....

Just my 2 kobo..... Cheers

Boss, you have been most helpful. I really really appreciate.

Looking at the Quanta, it is one brand i wanna keep. Mehn! a lot of work went into creating a Quanta. It is so solid, weighs heavier and finely built. Little wonder a new one costs an arm.

Having said that, i will go with option 2. But i am also thinking of buying and using that dollarnaira's "juju-charger"... ...to charge it instead. What do you think? Does it produce the recommended voltage?

Using the battery switch sounds like a good idea too. I will research on it.

ojeysky:


Charge and discharge efficiency of lithium is almost perfect; you get what you put in... attached is a full 14.3kwh LFP, notice the accuracy of the charge and discharge figures 20kwh (I did about 6kwh to full on BMV initially) is the difference and that has always been what I get at every cycle. In LA the difference will usually very and can be very significant in some cases

Did you actually discharge the 24V system to below 11V?
I thought lifepo4 cell is not expected to go below 2V.

mank1234:


Did you actually discharge the 24V system to below 11V?
I thought lifepo4 cell is not expected to go below 2V.

Naa ignore the min voltage, it occurred when I needed to do some maintenance and disconnected first set of the cells from the BMS(ANT BMS), the BMV was fast to capture the voltage of the remaining cells before I disconnected the rest. Unfortunately there is no way to reset just a data point on BMV without resetting everything so I lived with it. The max voltage is also not what I use normally (I do 27.6v), there was an event to that as well

ojeysky:


Naa ignore the min voltage, it occurred when I needed to do some maintenance and disconnected first set of the cells from the BMS(ANT BMS), the BMV was fast to capture the voltage of the remaining cells before I disconnected the rest. Unfortunately there is no way to reset just a data point on BMV without resetting everything so I live with it. The max voltage is also not what I use normally (I do 27.6v), there a one case event to that as well

OK. I understand now.

odimbannamdi:


Boss, you have been most helpful. I really really appreciate.

Looking at the Quanta, it is one brand i wanna keep. Mehn! a lot of work went into creating a Quanta. It is so solid, weighs heavier and finely built. Little wonder a new one costs an arm.

Having said that, i will go with option 2. But i am also thinking of buying and using that dollarnaira's "juju-charger"... ...to charge it instead. What do you think? Does it produce the recommended voltage?

Using the battery switch sounds like a good idea too. I will research on it.

Good choice my brother, find attached a picture of the switch am talking about from Jumia, u can also source locally, some people also make use of a knife switch but it's advisable you affix an isolator on the positive cables (which also looks like the battery switch) to avoid sparks.

On the issue of the "juju" charger, be aware that the charger outputs voltage in excess of 14.3 - 14.4v on normal battery mode but the good news is it has a dedicated lithium charging switch, so I presume it should be in the range of 13.8v or thereabout, which should work just fine.

So let's see how it works.... .

[b][/b]I have heard so much about quanta batteries. Please how do I differentiate the original ones from the substandard ones?

odimbannamdi:


Boss, you have been most helpful. I really really appreciate.

Looking at the Quanta, it is one brand i wanna keep. Mehn! a lot of work went into creating a Quanta. It is so solid, weighs heavier and finely built. Little wonder a new one costs an arm.

Having said that, i will go with option 2. But i am also thinking of buying and using that dollarnaira's "juju-charger"... ...to charge it instead. What do you think? Does it produce the recommended voltage?

Using the battery switch sounds like a good idea too. I will research on it.

Good day everyone. Please I need Lifepo4 battery SOC chart for 24v just for reference. Mostly what i see online are for lead acid batteries. Kindly share if you have any. Thanks.

IYGEAL:
I want to know something. As I currently use 600W PV to sufficiently charge my 200AH 12V Amaron Quanta battery, would same pv be able to charge 12v 200AH lithium ion phosphate battery?

If not (as I suspect), what pv capacity would be enough to charge the latter?

Also, what would be the difference in performance of both batteries when fully charged and running same load of say, 300W max?

12v 200ah quanta will fail earlier running 300w load, while the lithium will have no negative effect

saint2ace:



Good choice my brother, find attached a picture of the switch am talking about from Jumia, u can also source locally, some people also make use of a knife switch but it's advisable you affix an isolator on the positive cables (which also looks like the battery switch) to avoid sparks.

On the issue of the "juju" charger, be aware that the charger outputs voltage in excess of 14.3 - 14.4v on normal battery mode but the good news is it has a dedicated lithium charging switch, so I presume it should be in the range of 13.8v or thereabout, which should work just fine.

So let's see how it works.... .

Alright. I will do extensive research on the battery switch and its installation.

Regarding the charger, i will connect with dollarnaira to know which of the charging features gives the 13.8v.

ebocoms:
Good day everyone. Please I need Lifepo4 battery SOC chart for 24v just for reference. Mostly what i see online are for lead acid batteries. Kindly share if you have any. Thanks.

Find attached chart for 12v, multiply the voltage by 2 to make 24v. The chart is also why charging lithium at high voltages is not necessary.

Edit: The attached chart is for LFP chemistry

Many thanks

ojeysky:


Find attached chart for 12v, multiply the voltage by 2 to make 24v. The chart is also why charging lithium at high voltages is not necessary

earthrealm:


12v 200ah quanta will fail earlier running 300w load, while the lithium will have no negative effect

Thanks for your response.

I was actually trying to find out the duration (in hours) for which each would likely run the 300W load before dropping to say, 12.2V.

ojeysky:


Find attached chart for 12v, multiply the voltage by 2 to make 24v. The chart is also why charging lithium at high voltages is not necessary

This would be helpful to me as well.

But is this true for all Lithium chemistries or just LFP?

Charging profiles differs across various Lithium chemistries. The chart is applicable to only LiFePO4 chemistry.

ojeysky:


Find attached chart for 12v, multiply the voltage by 2 to make 24v. The chart is also why charging lithium at high voltages is not necessary

adrusa:


Maybe water was getting into the enclosure way more than usual.

Water got in.

dapsyra:
Charging profiles differs across various Lithium chemistries. The chart is applicable to only LiFePO4 chemistry.

IYGEAL:


This would be helpful to me as well.

But is this true for all Lithium chemistries or just LFP?

Absolutely correct, I should have made that distinction, LFP was just what came to mind when the op asked

ojeysky:




Absolutely correct, I should have made that distinction, LFP was just what came to mind when the op asked

Noted. Thanks.

Pertinent to note that voltage is not an accurate representation of state of charge and this is even more the case for most Lithium chemistries especially at partial state of charge.

I witnessed a Felicity Lithium pack go off at 50.2v after two days of low charge. One would have thought at least 30% capacity left at that voltage but the BMS tripped things off.

ojeysky:


Find attached chart for 12v, multiply the voltage by 2 to make 24v. The chart is also why charging lithium at high voltages is not necessary.

Edit: The attached chart is for LFP chemistry

NiyiOmoIyunade:
Pertinent to note that voltage is not an accurate representation of state of charge and this is even more the case for most Lithium chemistries especially at partial state of charge.

I witnessed a Felicity Lithium pack go off at 50.2v after two days of low charge. One would have thought at least 30% capacity left at that voltage but the BMS tripped things off.

That happened due to cell imbalance, one of the cells got to the low cut off voltage of the BMS (usually 2.5v for LFP some set higher but below 3v) for a balanced cell pack, the voltage indeed does the indicate the battery SOC, it's more accurate with no load.