Bielie

Old foto of current system. Before battery charger was installed.

Thank you, really appreciate the feedback. Struggling to find some good advice and the little knowledge I got is more dangerous than anything else. The "experts" that installed the current system in early 2014 was clearly not that. Approached someone now in the Mpumalanga-Badplaas area to have a look and got a quote for exactly the same batteries we can get from First National for R140k, for R190k. R50k on top. No suggestions for alternatives or even questions. So the only interest is to make a quick buck. Can up it to 5 pylontechs and it will still be way below the R140k (inc VAT) that the lead acid replacement is going to cost. I will have to go and measure the exact usage again. Not permanent on the farm. Roughly something like this (wattage is a guess in some instances): 24x7: 2 green energy refrigerators (+-150w each?), security camera system (+-10w) with a vhf radio system (+-1w in standby?), electric farm fence system (+-30W), alarm system + modem (+-2w) At night about 8 x 15W security flood lights activated by a day night switch. In the house at night for about 3 hours: Led down lights 3W X 15 , sometimes use of 2 x Laptops, sometimes charging 2 x Cellphones Might be missing something. Completely off-grid, no Eskom but there is a diesel generator with a battery charger as backup. Not sure if this will still work ok if we replace the lead-acid batteries with Pylontechs. I think the battery charger is connected via the inverter to charge the batteries but might be completely wrong. Yes correct that is the Inverter options. Its an old generation inverter catering for lead-acid. Will this really be a problem? I see you mentioned "BMS will only let battery discharge down to 80%", so I assume they will just switch off. Will this be bad for the batteries or Inverter? Absorbing and Float voltage can be set in the Outback Flexmax 80 charge controller and the equalization can be disabled. But a bit apprehensive that it will not work, or we write the batteries off in a year or so. Maybe an option considering the R140k (inc VAT). From browsing on the forum, I saw an option from @Jaco de Jongh that looks like a good one, but not sure if I underestimate the cost or maybe missing something additional that will cost a lot, or maybe got the capacity requirements completely wrong: EasySolar 48/5000/70-100 - 230V-MPPT 150/100 With CGX With 5 x US3000 Pylontechs Not sure if there is a secondhand market for the current Omnipower inverter and Flexmax charge controller. We got about 6 years out of the lead-acids with the last year or so struggling along with not a lot of amp hours left. So we expect the same if we replace with lead-acid again, so anything at more or less the same price, that provides equal or better than that will be a bonus. Current batteries need a lot of maintenance, battery water, equalizing, etc. and as mentioned we are not always fulltime on the farm. The only good thing about the lead acid 2V batteries is that nobody will even try to steal them, and that they got this huge amp hour rating. With the lead-acid we also did not want to use things like the occasional micro-wave for 10 min, or occasional quick hairdryer or using the printer. Seems the Pylontechs will be more forgiving for things like that?

Thanks. The Flexmax 80 charge controller got settings for absorb and float voltage. I see recommended values of absorption voltage of 52.5V and float at 51.8V for the Pylontech batteries in a another topic on the forum, and should be able to set that on the FM80. 50% DOD on the lead acid batteries MTE 21S only give about 2500 cycles (+- 7 years on paper). Only got about 5 years out of the previous set with 40% DOD. https://www.battery.co.za/wp-content/uploads/2017/06/M_Solar_Dec_2016_.pdf Pylontech claims 10 year warranty and giving 6000 cycles @ 80% DOD, so tempted to go with that.

Hi All, I would really appreciate some advice please. Currently got a 48V off-grid solar installation on a farm with: Omnipower HT-B-S8000-48 8KW Pure Sine Wave Inverter Outback FLEXmax 80 Charge Controller 24 x 2V First National solar lead-acid batteries (+-1100Ah at C10) 12 x JA Solar 335W panels (+-4KW) Problem is that the lead-acid batteries has reached its end of life and we need to replace them. Option is to replace with the same 24 x 2V First National solar lead-acid batteries (+-1020Ah at C5). Looking at R120k which seems to be very expensive. Seems the better option is to look at maybe a bank of 4xPylontech US3000 (3.5KWh) Problem is the Inverter and charge controller we have is probably more suited for lead acid type batteries. So we need to understand if the inverter and charge controller will be compatible with the Pylontech batteries, and if we will get the same capacity. I also do not know how to compare the options as far as amp hours / capacity is concerned. Is it correct to say the 2V First National solar lead-acid batteries is +-13kwh based on 25% discharge (1100 * 0.25 * 48) compared to 4 Pylontech US3000 +- 14Kwh (not sure what is the relevance or comparative C rating on Pylontech)