Hi all, I am a bit confused when it comes to old inverters or in this case old mppt controllers and new lithium batteries. So my client has a Microcare inverter model 24/5000 so 24v 5kw teamed with a Microcare 100A mppt. Now he's been using old 105ah batteries but now wants to upgrade, he is happy with sticking to lead acid but lithium shouldn't be overlooked. We were looking at the PylonTech UP2500 but when i asked Microcare themselves they said both inverter and mppt needs to go in for upgrading. From what I have been reading is the UP2500 can only work on Voltronic inverters? Though I believe, especially with the US2000/3000 is that the battery has its own charge controller and BMS. So would this not make the UP2500 capable to work with the Microcare charge controller as long as the voltages and amperages  are set right? 

@GrimmyGrimReaper the problem is, the Microcare mppt settings is the problem, it can't adjust really low and the problem with the pylontech is that they charge really low volts and the there isn't really space for error with the unit. @plonkster can correct me but the charge rate of the pylons is 52.5v and max is 53.2 or 35.5 or something in that line, then the BMS cuts out.

Your option is to send the mppt in to MC for the new software that you have more space to adjust the volts and charge or the other option is to the DIY way and get lifepo4 setup from lithiumbaterysa.co.za . 

I'm running there batteries with my MC mppt 60a and got the settings just rite to charge my lifepo4's correct with my BMS. 

16 minutes ago, Gerlach said:

correct me

They want a charge voltage between 52.5V and 53.5V, and at 54V they switch off with no grace period. Due to calibration differences and the tendency of lithium cells to spike upwards above 3.45V per cell, I recommend you stick to the lower end of that scale 🙂

 

I just remembered something. There are adjustable pots on the board for calibrating the voltage measurement. If you don't care about an accurate measurement, you could always adjust that so the charger THINKS it is at 55V but really it is at 52.5V. I mean, this is a really really lousy suggestion, and it will completely screw up the stats of the device... but it will work 😛

Edit: those screws marked 5 and 6. They adjust measurements. I don't know which one is voltage. I suggest not doing this at all if you actually like the MPPT 🙂

Edited March 16, 20205 yr by plonkster

Sorry for the late reply. I understand now. The client wants nothing to do with either sending the unit in nor messing with it, so it'll be good 'ol fashined lead for him. But out of interest sake... The only important thing(s) when charging lithium batteries is the the correct voltages and not exceeding charge/discharge currents? obviously batteries with bms's and controllers