Problem only the professional people in this forum can fix it please help

[paulcheung]

You are welcome, cheers.

[Lacosteiq]

The power company and the electrical professionals using Watts or watt hours to record the consumption and capacity. They don't use amperes these days because the capacity on amperes change when the voltage changes, but the watts or the watt hours don't change, 1000 watt hour is 1000 watt hour doesn't matter how you wire your system, 12 volts or 120 volts. so if you use the watt hours to measure your system you will not confuse by the amperes.

My friend i do not know how to thank you i understand now what that mean i will chose the right type and capacity on my little experience i take from you


My regards for you and your family

[paulcheung]

The power company and the electrical professionals using Watts or watt hours to record the consumption and capacity. They don't use amperes these days because the capacity on amperes change when the voltage changes, but the watts or the watt hours don't change, 1000 watt hour is 1000 watt hour doesn't matter how you wire your system, 12 volts or 120 volts. so if you use the watt hours to measure your system you will not confuse by the amperes.

[paulcheung]

I am not sure what do you mean and what is the question is. but you do know 8 of the 12 volts 250 ah batteries is equal to 16 6 volts 250 ah batteries in capacity.

They make different size and voltage for different purposes, they make larger amperage with lower volt so the weight of one battery can be manage by a single man, they are try to avoid parallel strings so they make different amps hours with different voltage. 2 volts, 4 volts, 6 volts, 8 volts and 12 volts. FLA batteries are 2 volts cells, that is why you don't see 5 volt or seven volts. They reason is for weight management so you don't have to move a 2000 pounds battery.

[Lacosteiq]

What you calculate is partial wrong,

12 volts 250ah x8 is 96 volts 250ah or 48volts 500ah or 24 volts 1000ah or 12volts 2000ah.

6 volts 250ah x16 is 96 volt 250ah or 48volts 500ah or 24 volts 1000ah or 12 volts 2000ah or 6 volts 4000ah.

Your battery options is better you either use option #1, 8 12volts 250ah AGM wired 4 in series and parallel two string make it 48 volts 500ah.

You other option is #3 16 6volts 380ah wired 8 in a series and parallel the two strings make 48 volts 760ah. this will last longer and give you more power in case the grid don't come as planned in two hours.

#2 option will be under power as the batteries are not AGM and it will stress the batteries too much, the charging rate is over C8 rate and the discharge rate is also over the C8 rate.

#4 option is way over kill, at 3000ah you have problem to recharge the battery bank properly. and this option will cost you a lot of $$$$$$.

Cheers

My friend thank you for this explain but what i mean is when i use 12v 250AH *8= 48v 500Ah bank power is 2000amp
And the 6v 250*16= 48v 500AH bank power is 4000
What is the benefit of the total power bank when the hour rate is the same 500AH in 12v and the 6v
Is the 4000Ah = 2000ah

Regards

[paulcheung]

My friend

As you told me i must consider the hour rate on battery ampere size
Just as explain about battery bank capacity i need to know something i was thinking of last night

12v 250ah*8 parallel type = 48v 500AH total ampere in battery bank is 2000ah
6v 250ah *16 parallel type=48v 500Ah total ampere in battery bank is 4000ah

I am so sorry for this question but i have no experience and i do not find any other person help me to understand so i need your help

What you calculate is partial wrong,

12 volts 250ah x8 is 96 volts 250ah or 48volts 500ah or 24 volts 1000ah or 12volts 2000ah.

6 volts 250ah x16 is 96 volt 250ah or 48volts 500ah or 24 volts 1000ah or 12 volts 2000ah or 6 volts 4000ah.

Your battery options is better you either use option #1, 8 12volts 250ah AGM wired 4 in series and parallel two string make it 48 volts 500ah.

You other option is #3 16 6volts 380ah wired 8 in a series and parallel the two strings make 48 volts 760ah. this will last longer and give you more power in case the grid don't come as planned in two hours.

#2 option will be under power as the batteries are not AGM and it will stress the batteries too much, the charging rate is over C8 rate and the discharge rate is also over the C8 rate.

#4 option is way over kill, at 3000ah you have problem to recharge the battery bank properly. and this option will cost you a lot of $$$$$$.

Cheers

[paulcheung]

We are here to learn, so don't worry about too many questions. ask as much as you want just make sure don't make up your mind yet and feel upset when the answer is not what you want to hear.

Back to your situation, you can use the 12 volts 250 amps AGM batteries to make the bank. you will have 48 volts 500 AHS. that will be sufficient for your load of 62 amps. just remember the AGM batteries don't have the thick plates like the larger FLA batteries, so they won't last as long and they cost much more than the regular FLA batteries for the same capacity. Two strings of batteries in parallel is not optimal, but it is workable as you don't have many choices. if the price on 16 of the 380 amps 6 volt battery comparable to the 8 pieces 12 volts 250 amps AGM, you should go with the 16 piece 6 volts 380 amps wired 2 strings as it will last longer in your situation.

I hope this will help.

[Lacosteiq]

My friend

I know you will be boring because i ask too much but our battery option in my country is very very very low i can not find the battery type trojan you advice me now i have four option on my market and my money budget please advice me to chose one and i will take your advice

1- 8/pc 12v 250AH AGM type
2- 16/pc 6v 225AH
3- 8/pc 6v 380Ah
4- 24/pc 2v 3000Ah



As you told me i must consider the hour rate on battery ampere size
Just as explain about battery bank capacity i need to know something i was thinking of last night

12v 250ah*8 parallel type = 48v 500AH total ampere in battery bank is 2000ah
6v 250ah *16 parallel type=48v 500Ah total ampere in battery bank is 4000ah

what is the use of large battery bank if the hour rate is the same in both type and my load is 62 ampere this is i do not find any answer on the internet until now i hope you can explain to me


I am so sorry for this question but i have no experience and i do not find any other person help me to understand so i need your help

To discharge 50 amps in one hour on 250AH batteries, that is 5C discharge rate, it will be too much for the small capacity battery, it won't work, even on the 425 amps batteries you are pushing it. because Peukert's law will make the batteries has much less capacity. Please read this sticky.

http://www.solarpaneltalk.com/showth...teries-and-You

[paulcheung]

To discharge 50 amps in one hour on 250AH batteries, that is 5C discharge rate, it will be too much for the small capacity battery, it won't work, even on the 425 amps batteries you are pushing it. because Peukert's law will make the batteries has much less capacity. Please read this sticky.

http://www.solarpaneltalk.com/showthread.php?11906-Peukert-Law-Batteries-and-You

[Lacosteiq]

My friend

What you think if i use 24/pc 2v 250AH for the battery bank i respect your reply and your advice sir .

I don't know where you go find the calculations, I believe if it take more than 10 hours which should mean from total discharged battery to 100% SOC. that would take a long time.

Remember you only discharge your battery bank to less than 30% DOD. that is a little over 100 AHS, to charge the battery bank to 100% SOC it take some time as the last 15% absorbing charge take time. it usually take 2 to 4 hours for the 380AHS battery when battery in good condition.

In your case, the battery only discharge in the 12 hours period on 24 hours. you discharge 2 hours and charge 2 hours, you put back the amount you take out, the good thing is that the other 12 hours the batteries are not being discharged. you can take time and use that 3 two hour period to charge the battery to a 100% SOC. Because you are fully charge the batteries to 100% SOC each day, you are not likely develop sulfation in these batteries. Just remember if you use the 380 amp hours batteries, they are not the long lasting batteries like the 820 or 925 amp hours batteries, their plate are much thinner so they don't last as long like the thick plate bigger brothers.

[Lacosteiq]

My friend thank you for this information i will built the system with 8/pc 6v 420AH

Regards

I don't know where you go find the calculations, I believe if it take more than 10 hours which should mean from total discharged battery to 100% SOC. that would take a long time.

Remember you only discharge your battery bank to less than 30% DOD. that is a little over 100 AHS, to charge the battery bank to 100% SOC it take some time as the last 15% absorbing charge take time. it usually take 2 to 4 hours for the 380AHS battery when battery in good condition.

In your case, the battery only discharge in the 12 hours period on 24 hours. you discharge 2 hours and charge 2 hours, you put back the amount you take out, the good thing is that the other 12 hours the batteries are not being discharged. you can take time and use that 3 two hour period to charge the battery to a 100% SOC. Because you are fully charge the batteries to 100% SOC each day, you are not likely develop sulfation in these batteries. Just remember if you use the 380 amp hours batteries, they are not the long lasting batteries like the 820 or 925 amp hours batteries, their plate are much thinner so they don't last as long like the thick plate bigger brothers.

[paulcheung]

I don't know where you go find the calculations, I believe if it take more than 10 hours which should mean from total discharged battery to 100% SOC. that would take a long time.

Remember you only discharge your battery bank to less than 30% DOD. that is a little over 100 AHS, to charge the battery bank to 100% SOC it take some time as the last 15% absorbing charge take time. it usually take 2 to 4 hours for the 380AHS battery when battery in good condition.

In your case, the battery only discharge in the 12 hours period on 24 hours. you discharge 2 hours and charge 2 hours, you put back the amount you take out, the good thing is that the other 12 hours the batteries are not being discharged. you can take time and use that 3 two hour period to charge the battery to a 100% SOC. Because you are fully charge the batteries to 100% SOC each day, you are not likely develop sulfation in these batteries. Just remember if you use the 380 amp hours batteries, they are not the long lasting batteries like the 820 or 925 amp hours batteries, their plate are much thinner so they don't last as long like the thick plate bigger brothers.

[Lacosteiq]

Thank you my friend i will do that

Dear friend

If use 8/pc 6v 380AH to the inverter can 60amp charger charge them in two hour every calculator online i check told me it take 12-14 hour for full charge i need your experience to explain that for me .

[Lacosteiq]

Thank you my friend i will do that

The Rolls 6CS25P is good and Trojan IND17-6V also good.
THe FLA batteries still best value for station RE applications.

[paulcheung]

The Rolls 6CS25P is good and Trojan IND17-6V also good.
THe FLA batteries still best value for station RE applications.