EPEVER Tracer AN Series damaged with LiFePO4 if not using dry contact connection to inverter?

[Norwasian]

I'm finalizing my design, and already have two EPEVER Tracer 8420AN units planned to handle one string of panels each in conjunction with an LVTOPSUN inverter on a third string of panels with all three connected to a 51.2V, 280Ah LiFePO4 powerwall battery. As I'm studying the manual for the EPEVER units, I see this:

When the lithium battery and the inverter are used together, connect the
controller's (Load) dry contact to the inverter's start-stop dry contact. Otherwise,
the controller may be damaged

[EPEVER MPPT Solar Charge Controller User Manual, p. 13]

I don't even understand this. I thought the dry contact was for starting a generator. Why would it be connected to the inverter? And why would the Tracer be damaged if this connection does not exist? And if this is the case, how could anyone connect two Tracer units to one inverter in this manner? And, finally, what cable(s) would be used for this connection?

Is this for real?

 

[Norwasian]

Do any of you use a Tracer AN with a LiFePO4 battery? If so, are you using this dry contact connection?

 

[Norwasian]

The EPEVER manual is difficult to understand. I think @Browneye might know the answers I need, but I as I continue to study, I just have more questions.

1) Will the unit actually be damaged with a LiFePO4 battery? If so why and/or under what conditions?
2) What happens if running two EPEVER Tracer 8420AN charge controllers side-by-side without using the PAL-ADP-50AN Parallel Adapter? Will something break?
3) Where do I connect the inverter negative? to the Tracer's LOAD connector, or to the battery?

I hope someone can help to clarify before I do it all wrong and ruin something.

 

[mikefitz]

Will the unit actually be damaged with a LiFePO4 battery?

Perhaps if the BMS shuts down the battery. Experience indicates this rarely occurs. Other controllers, Victron for example operate happily under BMS shutdown.

happens if running two EPEVER Tracer 8420AN charge controllers side-by-side without using the PAL-ADP-50AN Parallel Adapter? Will something break

Don't think so. Most systems using multiple independent chargers don't have issues.

Where do I connect the inverter negative?

The inverter positive and negative to the battery.

don't even understand this

I don't either.
Perhaps the Epever load control can be used to disable the inverter at a low battery voltage, if the inverter has suitable control Inputs.
The worry that Epever may be concerned about, is low volt BMS battery shutdown. If the inverter can be disabled by the controller at a higher voltage that the BMS protection voltage, then there would always be a charge path to the battery.

 

[Norwasian]

Thank you for responding.

Perhaps the Epever load control can be used to disable the inverter at a low battery voltage, if the inverter has suitable control Inputs.
The worry that Epever may be concerned about, is low volt BMS battery shutdown. If the inverter can be disabled by the controller at a higher voltage that the BMS protection voltage, then there would always be a charge path to the battery.

But this would seem to address damage to the battery, not to the controller. The documentation says somewhere, IIRC, that the controller won't be damaged by being hooked up to the PV panels without the battery; however, the battery should be connected first so that it can establish the correct voltage for output (and I'm thinking that if the settings already specified the battery voltage, even this should be unnecessary).

Page 2 of the manual covers what is not warranted:

Disclaimers
The warranty does not apply to the following conditions:

• Damage caused by improper use or inappropriate environment (such as the humid, salt spray,
• corrosion, greasy, flammable, explosive, dust accumulative, or other severe environments).
• The actual current/voltage/power exceeds the limit value of the controller.
• Damage caused by working temperature exceeding the rated range.
• Arc, fire, explosion, and other accidents caused by failure to follow the controller stickers or manual
• instructions.
• Unauthorized dismantling or attempted repair.
• Damage caused by force majeure.
• Damage occurred during transportation or handling.

There is no mention of battery disconnect whatsoever.

Perhaps if the BMS shuts down the battery. Experience indicates this rarely occurs. Other controllers, Victron for example operate happily under BMS shutdown.

The inverter should have its own low-voltage cutoff, with no need for the controller to tell it anything.

 

[Browneye]

The EPEVER manual is difficult to understand. I think @Browneye might know the answers I need, but I as I continue to study, I just have more questions.

Written by Chinese engineers. Sometimes does not translate to English very well.
I don’t have all the answers, but I can tell you what I’ve experienced with my EPEver controllers.

1) Will the unit actually be damaged with a LiFePO4 battery? If so why and/or under what conditions?

The controller needs a power source to operate, so it needs to be powered on first before connecting a PV array.
The battery voltage must match the operating spec of the controller. You can’t connect a 12V controller to a 48V battery, for example. Battery chemistry is irrelevant.

2) What happens if running two EPEVER Tracer 8420AN charge controllers side-by-side without using the PAL-ADP-50AN Parallel Adapter? Will something break?

Not familiar with a parallel adapter. But generally two controllers can exist together on a circuit, however you need to adjust to account for the raised system voltage when one is charging. I have two and they don’t play well together - the bigger one thinks the battery is full when the smaller one is charging, and slows charge current. Battery voltage tends to rise above its resting state when charging, and drops below when discharging.

3) Where do I connect the inverter negative? to the Tracer's LOAD connector, or to the battery?

Inverter should be as close to your battery as possible for current draw. Its neg connects to a ground bus or the battery with sufficient wire size to accommodate the current it draws.

I hope someone can help to clarify before I do it all wrong and ruin something.

Still not clear on what you’re afraid you’re doing wrong.

And yes, a dry contact closure is simply a switch to turn something on or off. Some controller have this feature for ‘if/then’ conditions to do something like start a generator or switch something off.

 

[Checkthisout]

I have the 100 amp model.

I had a bad bms that shut down battery voltage many times and no damage to the controller occurred.

Yes it's operating with a lipo4 battery.

Did you already have the controllers? If not, just get the Victron ones instead. Their prices are comparable to the Epevers now.

 

[Browneye]

I keep threatening to replace my epevers with victron stuff. More reliable and robust, better documentation, superior engineering.

 

[Norwasian]

I have the 100 amp model.

I had a bad bms that shut down battery voltage many times and no damage to the controller occurred.

Yes it's operating with a lipo4 battery.

Did you already have the controllers? If not, just get the Victron ones instead. Their prices are comparable to the Epevers now.

Yes, I already have the controllers. They were the best quality, as far as I am aware, that I could find in my location for a charge controller. At least, they were about the only name brand with good online reviews in English. In Thailand, Victron is nowhere on the market, and having had a recent experience with purchasing an electronic item off of eBay, I know better than to test customs again on something like this. (It was a nightmare, with fines, etc. for not having asked permission to "import" beforehand, etc.--on a ~ $200 second-hand and "for parts" item.)

 

[Checkthisout]

Yes, I already have the controllers. They were the best quality, as far as I am aware, that I could find in my location for a charge controller. At least, they were about the only name brand with good online reviews in English. In Thailand, Victron is nowhere on the market, and having had a recent experience with purchasing an electronic item off of eBay, I know better than to test customs again on something like this. (It was a nightmare, with fines, etc. for not having asked permission to "import" beforehand, etc.--on a ~ $200 second-hand and "for parts" item.)

No problem then. The Epever's aren't terrible controllers or anything. Parallel communication isn't necessary, it's just nice to have.

 

[Browneye]

Yes, just hook them up with proper wire and fusing and see how it goes. They'll either charge or they won't. LOL

 

[Arttu100]

I have a Epever Tracer 10420AN solar controller and 4pcs Epoch B12100B 12V 100A Lifepo4 batteries in parallel (12V). Batteries have thermal cells. How do I get the battery heating to work correctly with the controller in freezing weather? The heating always stops at the very beginning, when the controller believes that the batteries are overcharged.

 

[Arttu100]

I have a Trace 10420AN solar controller and 4 Epoch B12100B 12V 100A batteries in parallel (12V). Batteries have thermal cells. How do I get the battery heating to work correctly with the controller in freezing weather? The heating always stops at the very beginning, when the controller believes that the batteries are overcharged.