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frontpage Posted by MinhTrinh • Apr 10, 2025
frontpage Posted by MinhTrinh • Apr 10, 2025

EF ECOFLOW DELTA 2 Max Power Station Extra Battery

+ Free Shipping

$759

$1,399

45% off
Amazon
31 Comments 27,001 Views
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Deal Details
EcoFlow Inc. via Amazon has EF ECOFLOW DELTA 2 Max Power Station Extra Battery (‎EFD350) on sale for $799 - $39.95 (apply promo code 25Y5OFFMH1 at checkout) = $759.05. Shipping is free.

Thanks to Community Member MinhTrinh for finding this deal.

Features:
  • Increase the capacity of DELTA 2 Max with an extra 2048Wh.
  • 2-6kWh expandable capacity to fit your energy storage needs.
  • Ideal for home backup, RVing, outdoors or even everyday use.
  • Get 10 years of daily use until hitting 80% of its original capacity. That's down to its LFP battery chemistry giving you 3000+ cycles.

Editor's Notes

Written by ValPal2011 | Staff
  • Our research indicates that this offer is $90.10 lower (11% savings) than the next best available price from a reputable merchant with prices starting from $849.15.
  • Don't have Amazon Prime? Students can get a free 6-Month Amazon Prime trial with free 2-day shipping, unlimited video streaming & more.
  • If you're not a student, there's also a free 1-Month Amazon Prime trial available.

Original Post

Written by MinhTrinh
Product Info
Community Notes
About the Poster
Deal Details
Product Info
Community Notes
About the Poster
EcoFlow Inc. via Amazon has EF ECOFLOW DELTA 2 Max Power Station Extra Battery (‎EFD350) on sale for $799 - $39.95 (apply promo code 25Y5OFFMH1 at checkout) = $759.05. Shipping is free.

Thanks to Community Member MinhTrinh for finding this deal.

Features:
  • Increase the capacity of DELTA 2 Max with an extra 2048Wh.
  • 2-6kWh expandable capacity to fit your energy storage needs.
  • Ideal for home backup, RVing, outdoors or even everyday use.
  • Get 10 years of daily use until hitting 80% of its original capacity. That's down to its LFP battery chemistry giving you 3000+ cycles.

Editor's Notes

Written by ValPal2011 | Staff
  • Our research indicates that this offer is $90.10 lower (11% savings) than the next best available price from a reputable merchant with prices starting from $849.15.
  • Don't have Amazon Prime? Students can get a free 6-Month Amazon Prime trial with free 2-day shipping, unlimited video streaming & more.
  • If you're not a student, there's also a free 1-Month Amazon Prime trial available.

Original Post

Written by MinhTrinh

Community Voting

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Get Deal at Amazon

Price Intelligence

Model: EF ECOFLOW DELTA 2 Max Power Station Extra Battery, 2048Wh LiFePO4 (LFP) Battery, Compatible with DELTA 2&DELTA Max 2000&DELTA 2 Max Outdoor Generators

Deal History 

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Post Date Sold By Sale Price Activity
07/15/24Amazon$999
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Top Comments

This is just the extra battery. Not the power station. Its much cheaper to just buy a 100ah lifepo4 for like $100 and plug it into the solar port. You can buy as many as you want. Each 12v 100ah battery is 1280wh. Charge them either with the alternator charger or get a car or lifepo4 charger seperately. The alternator charger is $220 on ebay right now refurbished... you plug in your delta 2 into ac, the delta 2 takes 1000w and the alternator can take 800w, or adjust it however you want. the same with plugging it into a generator. which is what I will be doing during a blackout. charge the ecoflow during the day from a generator and using the alternator charger to charge up my 12v lifepo4 packs.

31 Comments

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Apr 11, 2025
1,164 Posts
Joined Dec 2013
Apr 11, 2025
killercut
Apr 11, 2025
1,164 Posts
Quote from DocuMaker :
i think $759 is not a good price for only a small 2kwh add-on battery. sorry, but i thumbs downed this deal. you can almost buy an entire brand new delta 2 max for this price, and with this you are only getting a simple dumb battery. if you buy a delta 2 max, you are not only getting 2 kwh of battery storage, but also the inverter, solar charge controller, and all the rest of the gizmos.

home depot is selling the delta pro ultra 6.144 kwh batteries for $1599. (even less if you use a home depot coupon, like $15 off $100, or $75 off $500, etc.) that battery has three times the capacity as this one (6kwh vs. 2kwh), but three of these at $759 totals $2277, vs. $1599 for the same capacity of the delta pro ultra battery. of course, i realize that the delta pro ultra battery does not work with the delta 2 max, but the battery is still overpriced for the capacity you get.

which is why killercut was suggesting you can buy non-ecoflow batteries to expand the capacity of your delta 2 max. for $759, you can almost buy a 48 volt server rack battery, which is 5.12 kwh, vs. this one, which is only a measly 2 kwh.

so, you are paying nearly 2 1/2 times the price per watt, compared to a budget brand server rack battery, just to add a couple kwh of battery storage.

i get that it is nice to have the matching ecoflow branded expansion battery, and it seamlessly integrates and communicates with the ecoflow power stations, but imo, it's still not worth it for this price.

if it were me (i realize everyone is different and may not agree), but i would rather take the $759 and buy a bluetti elite 200 v2, which i think is an overall better power station than the delta 2 max. you still get your 2 kwh of battery capacity, but you also get an extremely efficient (and quiet) 2600-2800+ watt inverter, in a nice compact form factor, that can allow you to take in up to 1000w more solar.

i just don't think this deal is all that great. a good deal on this battery would be more like 500 or 600 tops.

Forget the bluetti, go for the delta 3 pro if you need more power. Refurbished for $2000 on ebay or get the 2 pack from costco and return rebuy when the price drops again. It has 240v which makes it a lot more useful. Also has higher voltage solar input so you can connect some serious solar arrays.
Apr 11, 2025
348 Posts
Joined Jan 2015
Apr 11, 2025
ShiftinAt8600
Apr 11, 2025
348 Posts
Chase 5% Amazon back makes this a good deal. In for one, thanks OP.
Apr 11, 2025
90 Posts
Joined Jul 2016
Apr 11, 2025
3051
Apr 11, 2025
90 Posts
Quote from DocuMaker :
you said: "Its much cheaper to just buy a 100ah lifepo4 for like $100 and plug it into the solar port."the alternator charger does not plug into the solar port. it plugs into the expansion battery port. so, i was talking about for those who do not have an alternator charger, which costs $200-$300, and just want to use an inexpensive o-ring to xt60i cable for around $10-$15 plugged into the pv port. at 12v they will only be able to feed the solar input ~200 watts using one of those cables. not everyone wants to spend a few hundred on an alternator charger. some might want to use a 15 dollar cable to feed the power station up to 500 watts from an external battery (at higher voltages).obviously if you have an alternator charger, you can feed the power station up to 800 watts from a 12v or 24v battery or reverse charge and charge the external battery using the power station. i was using my alternator charger today, so i am familiar with how it functions.
So when you have the alternator charger hooked up, and your vehicle running, do you have nearly unlimited run time with the ecoflow delta? I'm looking to run a heat press from my truck during craft shows. The ecoflow can get the heat press started and up to temp, but it nearly fully drains it. The heat press usage drops significantly once it's up to temp since it only has to maintain and kicks on and off rather than staying on solid. I'm trying to avoid a traditional generator due to the noise, and I don't want another thing to have to maintain and carry gas cans for.
Pro
Apr 11, 2025
13,658 Posts
Joined Aug 2004
Apr 11, 2025
avalon
Pro
Apr 11, 2025
13,658 Posts
is there a special inverter that can be bought to act like a UPS with your own battery?

ie. it charges battery 24/7 off A/C and has a pass-through A/C outlet

but then switches to battery when loss of A/C detected and keeps A/C outlet going

?
Apr 11, 2025
1,472 Posts
Joined Jan 2009
Apr 11, 2025
DocuMaker
Apr 11, 2025
1,472 Posts
Quote from 3051 :
So when you have the alternator charger hooked up, and your vehicle running, do you have nearly unlimited run time with the ecoflow delta? I'm looking to run a heat press from my truck during craft shows. The ecoflow can get the heat press started and up to temp, but it nearly fully drains it. The heat press usage drops significantly once it's up to temp since it only has to maintain and kicks on and off rather than staying on solid. I'm trying to avoid a traditional generator due to the noise, and I don't want another thing to have to maintain and carry gas cans for.
with the alternator charger plugged into your compatible ecoflow delta power station, and your vehicle running, you should be able to indefinitely keep the power station going, as long as it doesn't overheat. i don't know how large your alternator is, and how much strain it can take while the truck is idling, but in the ecoflow app you can set the wattage in 50 watt increments from 100-800w, so you can set it to charge at 800, 750, 700, 650, etc. at whatever amount your alternator can safely output without causing it long term damage. trucks usually have beefy alternators.

with the alternator charger, you don't even necessarily have to have your truck idling using the vehicle's battery. you could just throw any spare 12v or 24v lifepo4 battery in the truck with you, and keep your power station charged up from the external battery, using the alternator charger or simply an o-ring to xt60i cable like this one:

https://www.amazon.com/dp/B0DT6ZPWFS

like i stated earlier, if it's a 12v battery, with this cable you are only going to be able to feed the power station a constant 180 watts or so (12 volts times 15 A max input on the ecoflow is 180). but since the delta 2 max has two dc/solar inputs, you could use two cables hooked up to the same 12v battery and double that to around 360+ watts input into the power station.

just make sure the spare lifepo4 battery is charged full before the show, and throw it in the truck with you. that's all you need to keep your ecoflow going without the noise of idling the truck or a generator.

it would be helpful to use a watt meter, like a kill-a-watt, to measure exactly how much energy the heat press uses for the duration of a show, and size your external battery (plus the 2kwh you get with the delta 2 max) accordingly.

if your delta 2 max runs the heat press for most of the show, and dies near the end, then you will only need a small inexpensive lifepo4 battery to keep it going until the end.

but yes, if you want indefinite run time, and your heat press uses less than a constant 800w, you should be able to keep the delta 2 max running indefinitely with the truck idling, as long as it doesn't overheat, and your truck alternator has no problem supplying the 800 watts at idle. i would imagine you would only have to idle the truck part of the time, to keep the power station charged up, but not the whole time.
Apr 11, 2025
532 Posts
Joined Nov 2005
Apr 11, 2025
391412
Apr 11, 2025
532 Posts
Please put 2048KW in the title
Apr 11, 2025
1,472 Posts
Joined Jan 2009
Apr 11, 2025
DocuMaker
Apr 11, 2025
1,472 Posts
Quote from avalon :
is there a special inverter that can be bought to act like a UPS with your own battery?

ie. it charges battery 24/7 off A/C and has a pass-through A/C outlet

but then switches to battery when loss of A/C detected and keeps A/C outlet going

?
i have never personally used one this way, so i don't claim to know from personal experience, but there are inverter-chargers with ups mode functionality built-in. the inverter-charger can charge your external batteries from grid-power (ac), and be configured to automatically switch over to drawing from the external battery or batteries of your choice, when a loss of grid-power is detected. people have been known to use victron inverter-chargers, like the multiplus, this way, as a ups, with their own batteries. but those are expensive and usually hung on the wall. i don't know if you were looking for something in a smaller form-factor and more inexpensive.

anyway, a small and inexpensive ecoflow river 3 plus can be used as a ups, and it can be fed a consistent 220w into the solar input, from an external battery or battery bank.

https://www.youtube.com/watch?v=aXQEMOYPgqw

if you require something larger and more powerful, just get a larger power station, like the delta 3 plus, use it as a ups, and keep it charged up and fed via the solar input from an external battery.

obviously you will have to come up with a way to keep the external batteries which are feeding your power station charged. you could charge them with solar, or with a standard battery charger plugged into the wall or power station, or use ecoflow's alternator charger.

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Apr 11, 2025
1,159 Posts
Joined Jul 2009
Apr 11, 2025
ViciousXUSMC
Apr 11, 2025
1,159 Posts
Once we get a good deal on the Max 2 by itself I might bite, best is a bit over $1000 with the alternator charger that I do not need, so waiting on better.
Apr 11, 2025
1,307 Posts
Joined Sep 2007
Apr 11, 2025
hallowmann
Apr 11, 2025
1,307 Posts
Quote from DocuMaker :
you said: "Its much cheaper to just buy a 100ah lifepo4 for like $100 and plug it into the solar port."the alternator charger does not plug into the solar port. it plugs into the expansion battery port. so, i was talking about for those who do not have an alternator charger, which costs $200-$300, and just want to use an inexpensive o-ring to xt60i cable for around $10-$15 plugged into the pv port. at 12v they will only be able to feed the solar input ~200 watts using one of those cables. not everyone wants to spend a few hundred on an alternator charger. some might want to use a 15 dollar cable to feed the power station up to 500 watts from an external battery (at higher voltages).obviously if you have an alternator charger, you can feed the power station up to 800 watts from a 12v or 24v battery or reverse charge and charge the external battery using the power station. i was using my alternator charger today, so i am familiar with how it functions.
Wait, so just to clarify, as I haven't even opened my alternator charger:
-Can I reverse charge a LiFePO4 battery with the alternator charger and charge it from the Delta 2 Max power station?
-Say I have a fridge/freezer attached to a DeltaMAX2+DeltaMAX2 expansion batt, can I then connect an additional LiFePO4 batt via the alternator charger to expand capacity to the extra expansion battery port?
Apr 11, 2025
36 Posts
Joined Nov 2021
Apr 11, 2025
MerryMusic9251
Apr 11, 2025
36 Posts
Super dumb question but how are you all charging these? Having someone install solar or is there a way I can do it much cheaper than these people who come in and want to charge $20k?
Apr 11, 2025
13 Posts
Joined Sep 2024
Apr 11, 2025
FeistyVest2189
Apr 11, 2025
13 Posts
Quote from Spartan805 :
Pin this!I thought it was a whole unit as well.
The crazy thing is I got a whole unit w 1028 (ish) Ah for 371 last year. Saw if for a couple bucks less not long ago.
Apr 11, 2025
90 Posts
Joined Jul 2016
Apr 11, 2025
3051
Apr 11, 2025
90 Posts
Quote from DocuMaker :
with the alternator charger plugged into your compatible ecoflow delta power station, and your vehicle running, you should be able to indefinitely keep the power station going, as long as it doesn't overheat. i don't know how large your alternator is, and how much strain it can take while the truck is idling, but in the ecoflow app you can set the wattage in 50 watt increments from 100-800w, so you can set it to charge at 800, 750, 700, 650, etc. at whatever amount your alternator can safely output without causing it long term damage. trucks usually have beefy alternators. with the alternator charger, you don't even necessarily have to have your truck idling using the vehicle's battery. you could just throw any spare 12v or 24v lifepo4 battery in the truck with you, and keep your power station charged up from the external battery, using the alternator charger or simply an o-ring to xt60i cable like this one:https://www.amazon.com/dp/B0DT6ZPWFSlike i stated earlier, if it's a 12v battery, with this cable you are only going to be able to feed the power station a constant 180 watts or so (12 volts times 15 A max input on the ecoflow is 180). but since the delta 2 max has two dc/solar inputs, you could use two cables hooked up to the same 12v battery and double that to around 360+ watts input into the power station. just make sure the spare lifepo4 battery is charged full before the show, and throw it in the truck with you. that's all you need to keep your ecoflow going without the noise of idling the truck or a generator. it would be helpful to use a watt meter, like a kill-a-watt, to measure exactly how much energy the heat press uses for the duration of a show, and size your external battery (plus the 2kwh you get with the delta 2 max) accordingly.if your delta 2 max runs the heat press for most of the show, and dies near the end, then you will only need a small inexpensive lifepo4 battery to keep it going until the end.but yes, if you want indefinite run time, and your heat press uses less than a constant 800w, you should be able to keep the delta 2 max running indefinitely with the truck idling, as long as it doesn't overheat, and your truck alternator has no problem supplying the 800 watts at idle. i would imagine you would only have to idle the truck part of the time, to keep the power station charged up, but not the whole time.
Thanks for the info. My truck has a 220 amp alternator so it's more than enough.
The delta 2 isn't enough to run the heat press for the whole show, it's literally only enough to bring the heat press up to temp, which is about 10-15 minutes and then it's dead, so I'll definitely need more than just another small battery. My only hope is the alternator charger, but then I may run into heat issues. I'll probably put a fan on it to help.
I ordered a refurbished alternator charger from the ecoflow eBay store this morning.
Apr 11, 2025
294 Posts
Joined Sep 2007
Apr 11, 2025
nononanette
Apr 11, 2025
294 Posts
I am in but I bought via Wellbots $779 OTD. Includes taxes and free shipping. With CHECKOUT20 code. AND 2% cb from Wellbots to spend at wellbots at a later date.
Apr 12, 2025
288 Posts
Joined May 2023
Apr 12, 2025
FairWinter2721
Apr 12, 2025
288 Posts
this is just an "Extra Battery." the Delta 2 Max can accomodate up to 2 extra batteries. HOWEVER, i recently purchased a Delta 2 Max refurb for $699 and opted to spend the money on a second rather than an extra battery. it cost less and adds way more capability. ur use case may vary, But i don't think this is the best deal. ALSO: be aware that EF makes several variants of the Delta Max. Not all have LFP batteries. Confirm battery type before purchase.

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Pro
Apr 12, 2025
8,627 Posts
Joined Nov 2006
Apr 12, 2025
infin8007
Pro
Apr 12, 2025
8,627 Posts
I want to buy a powerstation... to primarily be used for the typical blackout minimalist needs.

but i own a chevy volt and a 1500 watt inverter so i think i'll be covered...

well that saved me a few thousand i think lol
1
Apr 16, 2025
33 Posts
Joined Feb 2015
Apr 16, 2025
JasonG6464
Apr 16, 2025
33 Posts
Does anyone know if this would work as an expansion on the Delta 2 (not max)? Thanks!

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