EcoFlow Delta PRO Extra Battery review
My Delta PRO seems to be losing capacity over time, what can I do about it? (30s Recalibration Method)
Most probably your Delta PRO is not loosing capacity over time but instead the algorithm that tries to guess how much watts 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 (in the APP) 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 firmware 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.
_CLOSING THOUGHTS_
I think it is very beneficial to have an extra battery:
- You double or triple the capacity.
- You distribute the charge load onto more than one unit so you could charge at up to 4.500W (AC+SOLAR) without breaking a sweat as each battery would only charge at 4.500W/X so less battery heat and stress.
- You distribute the discharge load onto more than one unit so it could better handle high spiky loads (in my case 4.400W+ initial start) with lower temperatures, less battery heat and stress.
- You distribute the use cycles between the units so if before having an Extra Battery you used 1 cycle/day, now you would use 0.5 cycle/day per battery.
The one big disadvantage is that if your Delta PRO malfunctions, the Extra Battery will become a useless, very big and heavy paper weight until your Delta PRO is fixed.
Even with the few shortcomings like an unwieldly short cable, not being able to use the Extra Battery independently and the possible % imbalance between units (not in my case with factory firmware) I think the Extra Battery is a GREAT addition if you can catch a good offer as it makes it very easy to expand the capacity of a Delta PRO unit in a seamless way (in my case it was simple plug-play-forget). The looks are as sharp and beautiful (to me) as the Delta PRO. I want to congratulate EcoFlow designers and engineers on the inclusion of a spacious compartment, that I use to store all sorts of cables, on top of the Extra battery.
As a closing note, I would like to thank again JON/STABLECAM & HELEN/ECOFLOW for trusting me with the review of the Extra Battery.
Don’t hesitate to ask your questions in the comments section!
I see on your You Tube vid about fan noise that you’ve modified your Delat Pro to drop the noise to 40dB. Can you detail what the mod is? I’ve considered replacing the fans with “Arctic” brand low noise fans but would like to hear your ideas first.
Thanks!
Hi George.
This is what I wrote on YT in respect to the fans:
Hi There,
I wish I had discovered your forum sooner. I purchased the EF DP in September 2022 from Amazon along with a Solar Panel (of which I am yet to use). I had been using the unit to run large appliances during peak times and charge the unit during off peak periods via AC. I use the “Slow/Custom” switch and control the charge voltage in the app. I reside in Australia. The system has 4x 230V 10A sockets along for output. Generally, I am able to operate a dishwasher at 75 degrees C (167F) for 2hrs 10 mins and a 2hr 35 min load of laundry in my front load washing machine using cold water. Then the battery would be be at 1%. I purchased the EF DP Remote Control and immediately was disappointed that the screen kept timing out at 60 secs max despite it being connected to an always on USB-C cable. I had contacted EF Support to address this, they took an exceptionally long time in trying to help resolve the issue. I had to provide video evidence of what had been occurring. They said it was definitely faulty and they would be sending me a replacement. After the replacement had arrived, I had set it up and paired it successfully with my DP and connected it via Ethernet to perform a FW update on it. I immediately noticed that the issue was still present and called them out on it. They said this time it is a limitation of the FW and there is nothing further that they could do. I still have the other EF DP Remote with me and they have not requested it back – What gets me is why get me to go through the hell of trying to demonstrate an issue with their expensive remote control when they were already aware of it?? The eventually emailed me asking if I wanted to keep it or they would refund me for the purchase. I didnt reply as I thought whats the point, I would have to post one back to them and pay for shipping.
I recently purchased the EF DP Extra Battery for the insane price of $4369 AUD and have successfully connected it to my DP. I noticed after I had reached a charge of 100% (which both units were displaying), the app indicated a FW update was available and I updated thinking this is the correct thing to do. I am now sitting on V1.0.1.18 and V3.0.1.11 (WiFi) as displayed on the app.
My first operation was to run a full load of laundry in my clothes dryer with X-Boost turned on, running a Dyson Purifier Fan and a Dehumidifier at the same time and I had observed the Extra Battery was matching the output of the DP of 2500W+ at one time.
A week on using the EB I am not satisfied. The Extra Battery when in operation with the DP running the same load as before does not match any longer. The EB seems to max out at 1100W input to the DP and doesn’t assist the DP when its almost out of juice. I feel load balancing is a problem as it clearly cannot achieve this. I’ve also found that despite the EB having a higher charge remaining the DP continues to output a charge to “top-it-up” where as it should be doing the opposite and providing a charge to the DP.
I am currently charging my DP from 43% to 100% at 2000W (the max output from my outlet is 2300W, but sometimes trips the breaker). Whilst charging it is outputting 794w to the EB at the same time and both capacities are almost identical.
I only wish the EB would function as it was marketed to me as. I am somewhat happy with the EF DP however these FW issues are bugging me. I wish there was a was to reset back to stock FW. I have my unit connected to the internet and use it via Bluetooth when the internet goes down.
Appreciate your thoughts?
Thanks for reading.
– Daniel
Hi Daniel!
The EB & DP wil never be identical because of how voltage/charge transfer works.
When charging, the DP has a higher internal (battery pack) voltage than the EB so the EB can charge from the DP and the opposite is true when discharging; the EB will have a higher internal (battery pack) voltage than the DP so the DP can take energy from the EB.
What I’ve observerd is that the BMS (Battery Management System) will try to keep both battery packs (DP/EB) within 0.10V of each other
What you see on the LCD as % of charge is basically a (best case) guess when the battery (DP or EB) have had a full charge + state reset (State of Charge); the computer that manages the battery has an internal table of data that correleates voltage, temperature, cycles to an approximate, user facing percent of charge that will get out of sync (looses precision) the more you use the DP but the full battery capacity is stil there just not reported correctly to the user.
This past week, I’ve observerd an issue with my EB where after charging to 100% from solar, when disconnecting from solar, it would not share the load with the DP so the DP drained 20% while the EB didn’t budge (0 watts).
The only way to kick it out of it’s slumber was to drastically increase the drain on the system (DP+EB) from 200W to around 1.500W which finally woke up the EB and started draining 3:1 vs the DP to try and catch up (took a long time to almost catch up).
TLDR: It’s a BETA product that needs some nursing where you’ll have to jump in when an issue arises to fix it and go back to normal. The disparity between what is reported (%) and reality can become big with time/cycles and the only way to fix it is to reset the counter (check my articles for the 15 seconds procedure to reset it).
As for the REMOTE, it was an issue with early FW because it wasn’t coded properly so they finally took the time to implement it and then used the DP to reprogram the REMOTE so it wouldn’t turn OFF at 60 seconds __BUT__ you NEED to have the remote connected via ETHERNET/NETWORK cable when doing the FW upgrade and when using the device or it will revert to 60 seconds.
I have my remote via ethernet cable and it is on for 16+ hours a day since the last 9 months or so.
Hope this helps!
Take care.