June 8, 20224 yr The system is now running for 2 months now I'm so impressed with the money I already save on my utility bill,though I have a question,according to the specs for my 2 x Narada 48vdc 200ah Lithium lifepo4 10kw batteries, it must give me 10-12 hours power not sure it will manage that.I keep my baterys between 46v and 49v with the inverter settings.With a load usage of (1.28kwh to 1.57kwh) my baterys give me 4 Hours service before it have to use utility to charge for 20 min again from 46v to 49v to start with another 4 hours service again.Want to know if this is great or is the baterys bad if I don't get the 10 hours with the 2 baterys if I have loadsheding.Ore must I reduse my load usage more to obtain batery time.Thanx
June 9, 20224 yr Google to find the voltage range and set the inverter to that or post a picture of the specs. Just off the cuff 4 hours at a 1.5kw load is FAR too low for a 20kwh bank. 10 is more what you should be getting.
June 9, 20224 yr 8 hours ago, Wurm said: I keep my baterys between 46v and 49v with the inverter settings. https://mpinarada.com/48v-li-ion-lfp-10ah-to-200ah/ I looks like this is a 16S LiFePO4 battery (could not find it in the specs so I calculated it from the 40.5V low battery disconnect 2.5V per cell) The specsheet shows that you should charge to 54.5V which is probably in the high 90s percent (and the 0% point in 40.5V), so I would say you should not go lower than 46V, personally I would go for 48V minimum (3V * 16 cells as there is very little power left below that point) You are probably using the lower 0-40% of your battery which is not good for the longevity of the battery.
June 10, 20224 yr Author On 2022/06/09 at 7:58 AM, iiznh said: https://mpinarada.com/48v-li-ion-lfp-10ah-to-200ah/ I looks like this is a 16S LiFePO4 battery (could not find it in the specs so I calculated it from the 40.5V low battery disconnect 2.5V per cell) The specsheet shows that you should charge to 54.5V which is probably in the high 90s percent (and the 0% point in 40.5V), so I would say you should not go lower than 46V, personally I would go for 48V minimum (3V * 16 cells as there is very little power left below that point) You are probably using the lower 0-40% of your battery which is not good for the longevity of the battery. Hi iiznh I had set at first the minimum at 46v and max at 51v for switching between batery and utility but find that it took longer utility usage to get batery charged to the 51v mark to change back to batery,increasing my utility bill.The charging amps is set from 60- 80 the maximum setting my idle charge rate is 54v and the low cut off is 44v.Acording my inverter manual the settings is: 12=46v 13=54v 26=56.4v 27=54v 29=44v My settings at first for my baterys: 12=46v 13=51v 26=52.5v 27=53.6v 29=44v My settings at this moment: 12=46v 13=49v 26=54v 27=54v 29=44v I also notice my full batery indicater never go higher than the 50%-75% mark showing that batery is fully charged but voltage had shown 54v in some situations.Thanx
June 10, 20224 yr 34 minutes ago, Wurm said: I also notice my full batery indicater never go higher than the 50%-75% mark showing that batery is fully charged but voltage had shown 54v in some situations.Thanx Please read up a bit on LiFePO4 batteries, you are actively shortening the cycle life of your batteries. You should at least charge them to 54.4. Voltage is a very poor indicator to determine the state of charge. A LiFePO4 cell that reaches 3.45 - 3.5V is fully charged (*16 for a whole battery)... if you disconnect it it will settle on 54.0V (fully charged). If this was my solar rig I would charge up to 56V and float on 54V to get the cells a chance to balance. A balanced pack will have less chance of shutting down due to one cell being fully discharged. Depending on the BMS in your setup it might never get to the point where it top balances the cells. You might be confusing Lithiuim-ion (Li Cobalt Nickel) wich is recommended to be charged to 90% with LiFeSO4 which should be charged to 100% to ensure top balancing
June 14, 20224 yr Author Hi iiznh I checked my batery status it is 15sell.At first i try the 48v and 56v suggestions but it seems that after the baterys get to 51.5 v it takes forever to change further I set the the settings to: 12-46v 13-51v 26-56.4v 27-54v 29-44v The sells now run between 3.4v and 3.06v / Sell an give me now about 10 hours of discharge at 1.5kwh
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