EcoFlow Delta PRO 6+ months review

_Q & A_

This section will be constantly updated with answers to questions and doubts you may have related to the Delta PRO. If your question is not answered here, ask it in the comments section below and I’ll do my best to answer it here.

My Delta PRO seems to be losing capacity over time, what can I do about it?

Most probably your Delta PRO is not loosing capacity over time but instead the algorithm that tries to guess how much capacity is left in the battery is wrong because of a drift over time as it is not precise and the LFP chemistry has a very flat Voltage discharge curve that makes it very hard to guesstimate correctly.
During the first week of receiving my Delta PRO, I developed a method that resets the estimate so it reports correctly the capacity. My method only takes around 30 seconds to do and doesn’t needlessly stress the battery (by draining it to 0%!!) but you have to follow it exactly as stated below.

• Monitor your Delta PRO when it is about to reach 100% and be ready.
• The instant you see that the Delta PRO has reached 100% and has stopped charging (no more blue spinning wheel), disconnect all charge sources (disconnect mppt/ac).
• After disconnecting all charging sources, press & hold the POWER (golden/yellow round) button for 15 seconds. If you’ve done it right, after less than 1 second of pressing the button, you will briefly see “OFF” on the LCD “OUTPUT”. Please be advised that by turning OFF the Delta PRO, the inverter/DC/USB will turn OFF too.
• Wait 3 seconds and press again the POWER button for 1 second to turn the Delta PRO on again.
• One way to confirm the success of the reset procedure is to check if the WIFI icon is missing just after turning on the Delta PRO (if you have your unit connected to the internet). After a few seconds you will see the WIFI icon come back again.
• Check that the unit now reports around 10D13H of available capacity which translates to about 3.648W of available (user accessible) capacity.
• Don’t (be greedy and) try to extra-charge your Delta PRO as you may risk getting an “overcharge” error code and the unit turning off (remote chance but could happen). Only connect charge source when you’re already discharging your Delta PRO, not before.

This procedure works with ALL FW versions from 0.1.0.0 up to latest available. I’ve been observing that after a few daily resets I don’t have to do it as often to the point where now I might do it every two weeks.

My Delta PRO is still loosing capacity and sometimes turns off before reaching 1% available capacity!

If you are absolutely sure that you’ve correctly done the previous reset procedure and it didn’t help at all then you might have a battery cell that is out of balance so you will need to force the BMS to do a hard recalibration of the battery pack. Please follow the procedure exactly as stated.

• Charge your battery to 100% as you usually do.
• Once the Delta PRO reaches 100% and the blue circle stops spinning, disconnect all charging sources and start discharging it. Try to stay at or below 0.5C (<1.800W).
• Once the Delta PRO reaches around 20% remaining charge, reduce discharge rate to below 200W (100W optimal) and keep it stable (no fluctuations whatsoever!). Be advised that it might take a long time to reach 1% so be patient.
• Once the Delta PRO reaches 1% actively monitor it until it turns OFF.
• Once the Delta PRO has turned OFF, wait 5 minutes, turn it ON again and let it recharge at a rate that is < 900W. At 900W it should take less than 5 hours to top up. Do not use the Delta PRO while it is charging (no AC/DC/USB output at all).
• Once the Delta PRO reaches 100% and the blue spinning circle stops, you can use it as you always do.
• Test that the Delta PRO is back to normal/expected capacity.

If you have followed the procedure and you still have the same issue then I would advise you to contact Ecoflow Support and clearly state your problem and all the steps you have followed to remedie the issue before contacting them. Hopefully this will accelerate their response/next steps.

I’ve heard that I need to keep the Delta PRO between 20%-80%. What’s the proper battery care for the Delta PRO?

From my personal experience and after 9 months of 24/7 usage I can tell you that you don’t need to micro-manage the Delta PRO.
First of all, the Delta PRO uses LFP (Lithium-Ferro-Phosphate4) battery cells that are a lot better at taking abuse (thousands of cycles) than common LI (Lithium-Ion, hundreds of cycles) cells. The clever engineers at Ecoflow reserved around 3% of extra battery for internal functions & protection (which is the logical thing to do) so even if you run your battery flat (0%) in reality it still has around 3% of battery that is only accessible to internal electronics so the battery is still protected. There’s only one case where you could damage your battery if you run it to 0% and then let it sit at that 0% for an extended period of time as there’s always internal discharge to keep the BMS and other electronics on & managing the Delta PRO even if it appears OFF to you. Once you reach 0% shut-off I advise you to recharge the Delta PRO as soon as possible so as to avoid this situations.

I use my Delta PROs 24/7 without any (app) artificial limitations (so 0%-100%). My typical daily cycle is 50% back to 100% (until battery charge is 0W) and then back down to 50% until the cycle is repeated again the next day. As I get into the winter season the 50% will surely drop even further as my panels are not optimally placed due to location constraints. After 9 months of 24/7 use with 100% charge, the internal capacity of the Delta PROs hasn’t changed at all so you shouldn’t worry too much about having to micro manage it.
Always keep in mind that the batteries decay even when not used or abused as they have a natural decay factor which is the unescapable CHRONOS so I wouldn’t stress over “nursing” Delta PRO’s LFP battery. This is the first battery that I don’t actively micro-manage and just use it.

What you really need to take care of is TEMPERATURE as it is the number 1 battery killer. Even though the Delta PRO’s BMS takes into account the battery temperature when charging/discharging (temperature along with battery chemistry is some of the most important parameters that the BMS needs to manage the cells) you should actively avoid high temperatures when operating the Delta PRO or storing it. The Delta PRO has 4 loud fans but they are useless even when at full blast if the intake temperature is high as the only thing that has active cooling is the electronics and NOT the battery and if your intake temperature is xxC, the electronics will never be below xxC and the battery will be higher than that.

Also do NOT block the intake/exhaust vents of the Delta PRO as that will dramatically increase the electronics temperature which will increase the battery’s temperature. Always provide adequate space for intake (right side of the Delta PRO when looking at the LCD) and exhaust and if you need to put an Extra Battery close to the Delta PRO, always put it on the LEFT side of the Delta PRO (exhaust side).

If you still are not convinced and want to put a limitation then I’d advise going with 10%-95% but know that in emergency situation you can use 100% to 0%.

I want to store my Delta PRO and only use it for emergency situation. What’s the maximum recommended storage charge?

Remember high temperature is the number 1 battery killer so always keep that in mind and store the Delta PRO in a cool environment with low humidity. Also make absolutely sure that you turn OFF the Delta PRO by keeping the power button pressed for 5 seconds and that you see the LCD flash OFF for a second before turning off.

I would store the delta PRO with 95% max charge to have it ready for an emergency (although in my specific case I use it 24/7/365). Of course it would be wise to turn on & use (discharge/charge) the Delta PRO every 3 months just to move some electrons around and make sure that everything is ok.

If you want to store the Delta PRO long term then the best option would be to store it at around 50% capacity and make sure to truly turn it OFF (see above).

Is it OK if I put my Delta PROs in a small/utility/boiler room to dampen the infernal noise?

NO. Delta PRO’s number one enemy is HEAT (temperature) so if you put it in a closed space with no active ventilation you will soon find out that the room’s temperature will start to climb rather quickly (depends on external ambient temperature and cubic meters). I would also advise against a room where there’s water/vapor/potential for water leaks as liquids and electronics don’t mix well.
For sure it would have been VERY nice if Ecoflow would address & fix the infernal fan noise of the Delta PRO as I think it affects user experience in a very negative way. Those who have it in their garage would think that this is irrelevant and nitpicking but what if you have to run your Delta PRO in a camping setup or a room with people inside or some other setup where noise is important…?

If you absolutely have to put your Delta PRO in a small closed utility room, do make sure that the room has some active ventilation, that you don’t obstruct intake/exhaust fans and leave enough clearance around the Delta PRO.

Cloud Server is down and my APP doesn’t connect via Bluetooth to my Delta PRO; what can I do?

Early on, Ecoflow decided to give maximum priority to their cloud servers for data harvesting and hamper as much as possible the local (Bluetooth) connection to the Delta PRO so the user would always prefer to use “ONLINE” instead of offline.
I reported that long time ago but they didn’t listen (well they politely said it was a great suggestion and then nothing happened lol xD) so I had to find a way to connect to my Delta PROs in an easy way via BT without having to jump through hoops.
The app will go out of it’s way to connect via the internet, be it on wifi or mobile connection and will absolutely not want to connect to the Delta PRO via BT.

The only way to connect to the Delta PRO via BT is to BLOCK all other means of connection so it gives up and tries BT as a last resort.
To do that you need to disable WIFI & 3G/4G (ALL DATA) and relaunch the APP for it to connect via BT. Once you confirm the APP is connected via BT, you can enable WIFI/3G/4G and go on as usual but DO NOT CLOSE/KILL the APP or else you will have to repeat this procedure again.
NO you don’t need to pair it again nor press the IOT button or anything like that if you haven’t deleted the BT pairing on your phone.

In my case, I have a firewall on my JB iPhone that filters out all comms so I can easily force the Ecoflow APP to connect only through BT while the phone is connected to WIFI and business is as usual but for that you need a Jailbroken iPhone and some tech knowledge.
If you have an Android phone then I guess it might be easier (?) to have/install a firewall and replicate my setup.

PS: Even if you connect by BT to the DeltaPRO you will notice a certain lag when sending commands as the DeltaPRO will INVARIABLY connect to the CLOUD to process the command and get back a response before actually doing anything. I’m sure it is to keep everything in sync (all possible endpoints). The only way to avoid this delay is to cut the Delta PRO’s access to the internet but that would negate the “IOT” functionality (remote monitoring & control).

PS2: All this has been confirmed for all Firmwares up to 1.0.0.85 (After all the big problems, I refuse to update)..