iSunergy MPPT charge controller

[n4mwd]

I bought an iSunergy MPPT solar charge controller off Amazon. So far I am not happy with it due to the lack of documentation.

As such, I need help figuring out the settings. The manual simply gives huge ranges and you are supposed to guess at a good setting. The factory said they don't give out the exact settings.

The following are what I can actually change on the controller:

Under Over discharge Voltage
Under-R Over discharge return
OVD Over Charge Voltage
OVD-R Over charge return
Float Float charge voltage
BCV Boost charge
ECV Equalizing Chage Voltage

Does "return" mean "reconnect" here????

The manual actually lists the following fields in its broad range sample settings, but with no place to put them in the actual unit:
Charge Limit Voltage
Boost Charge Return

I am in the process of building a 48V portable solar generator system. My panels and batteries have not come yet, so I am testing on a 12V flooded lead acid system that I have. The final battery bank will be 16s Lifepo4 80 Ah cells if it ever gets here.

Anybody have an idea how to set the parameters on this thing for 16s Lifepo4 as well as 12V flooded lead acid? I'd like to get it working on FLA first because they are harder to destroy than LFP batteries. That and I don't really trust it just yet.

 

[gnubie]

I'll take a guess that:

- over discharge return refers to the voltage the charger has to raise the battery to in trickle charge mode before it will recommence normal charging processes to avoid damaging the battery.

- over charge return refers to the voltage the battery has to fall to before the charger will recommence normal charging processes to avoid damaging the battery

 

[n4mwd]

- over discharge return refers to the voltage the charger has to raise the battery to in trickle charge mode before it will recommence normal charging processes to avoid damaging the battery.

- over charge return refers to the voltage the battery has to fall to before the charger will recommence normal charging processes to avoid damaging the battery

The "damaging the battery" is the part I'm worried about. The Float and Equalizing Voltage settings might be appropriate for FLA, but might damage a LFP battery.

I am looking at the Victron 75/10 that I pulled out of there to test this controller and this controller actually does have better specs if they are real.

 

[gnubie]

Your BMS will prevent under / over voltage on the LFP so it's not as critical for that part, but you don't want the BMS to step in and disconnect so you'd set your overcharge voltage to just under your BMS high voltage cut off. The charger should never get to BMS cut off voltage, this is just a safety net incase it approaches it.

Over discharge return, if it's what I suspect it is, should be set quite low as if your BMS disconnects due to low voltage cut off you want the charger to be able to spring back into life and wake the BMS again. You may find the residual voltage on the battery terminals falls to under 8V with almost no current (microamps) if the BMS disconnects. The over-discharge return voltage would be set below what ever voltage is present when the BMS disconnects.

Equalise should be turned off or at least set to float for lifepo4. IMO float should be set to 13.5 (12V battery) and absorption to 14.2V. If you can set tail current or max absorption time you should do that too to ensure the lifepo4 is not overcharged.

 

[n4mwd]

Your BMS will prevent under / over voltage on the LFP so it's not as critical for that part, but you don't want the BMS to step in and disconnect so you'd set your overcharge voltage to just under your BMS high voltage cut off. The charger should never get to BMS cut off voltage, this is just a safety net incase it approaches it.

Over discharge return, if it's what I suspect it is, should be set quite low as if your BMS disconnects due to low voltage cut off you want the charger to be able to spring back into life and wake the BMS again. You may find the residual voltage on the battery terminals falls to under 8V with almost no current (microamps) if the BMS disconnects. The over-discharge return voltage would be set below what ever voltage is present when the BMS disconnects.

Equalise should be turned off or at least set to float for lifepo4. IMO float should be set to 13.5 (12V battery) and absorption to 14.2V. If you can set tail current or max absorption time you should do that too to ensure the lifepo4 is not overcharged.

I am planning on going without a BMS with the 48V LFP solar generator. The reason is that the charge controller should protect from over voltages and the inverter should protect against under voltages. I do have a 16s inductive balancer, but it does not have any protection circuitry. I may have to get one anyway, but that was the plan.

There is no setting to limit the time in equalization or turn it off. I'll try setting it and float to 13.5V. There is no absorbtion setting. I guess that must be equivalent to Boost Charge Voltage.