Simultaneous Charge/Discharge (pass through?) on all-in-one systems and impact on battery longevity. Considering Bluetti AC200 and EcoFlow Delta

solar_shedquarters

Systems Engineer
Joined
Jul 2, 2020
Messages
6
Hello,

I'm looking to setup an all-in-one system for my shed to power some PCs and air conditioner, but I also want the all-in-one for power outages in the house (we're in California fire country), and camping.

I've got an order in for the Bluetti AC200, but am also considering the Delta Ecoflow.

I am trying to learn if it is "healthy" for the batteries to be simultaneously charged by a solar panel or a gas generator, while also discharging the battery to power things like my air conditioner or refrigerator.

Sometimes, solar (or gas) generation will exceed my output and I'd like to store the extra energy, and other times I'll need to utilize both battery and solar power simultaneously to power everything.

What I'm trying to learn:
1.
Is what I'm describing correctly called "pass through" charging, or an inverter "bypass"?
2. When I look at all-in-one specs, is there a way to determine if a product has pass through charging?
3. If a system does not have pass through charging, how much damage would I be doing to the battery if I do this daily? Instead of daily what if it was just during emergencies/ camping (20 days a year).
4. It seems odd some vendors would design a "solar generator" system to be charged or discharged at separate times-- am I missing something, or is this just an inverter cost cutting issue?
5. Between the EcoFlow Delta and the Bluetti AC200, would one system be better for this? It seems like the Bluetti has better battery cycle stats, but I thought I heard something about the EcoFlow having a bypass. Happy to do my own research, but if somebody knows off hand, I'd appreciate it.

I'm not willing to go for a full DIY system because I want the versatility to take it camping, etc. -- However, if there is some extra gear I could get in addition to the all-in-one to make this work in the shed, I'd be OK with it.

Thanks in advance for the help-
Solar_Shedquarters


Q/A from Bluetti AC200:
1593725812159.png
 
Its not really cost cutting, its just not built to do it that way. Most DIY systems are the same way, they use the battery as a buffer, even if its just for a tiny bit. In truth, if you draw 600 and the panels are 700, you'd be net positive and charge the battery a bit. But if a cloud rolls by and your only producing 500, the unit will suck 100w from the batteries.
Inverter bypass is generally not a term I'd say is used for these portable systems. Its generally when you pass the load off to the grid. In this case, by passing the inverter would get you at best to the solar charge controller, which is DC power anyways.

all the USB charging stuff is probably just a step down transformer to 12V (for 12V accessories) and then 12V to 5Vfor usb.

It can possibly diminish service life, as each time you charge up and dip down its technically a cycle.

That said, small cycles like that aren't the worst thing, but doing it close to 100% SOC may not be healthy for it either.

EV cars use regen braking, its kinda the same thing. Little charges here and there.
 
Last edited:
Its not really cost cutting, its just not built to do it that way. Most DIY systems are the same way, they use the battery as a buffer, even if its just for a tiny bit. In truth, if you draw 600 and the panels are 700, you'd be net positive and charge the battery a bit. But if a cloud rolls by and your only producing 500, the unit will suck 100w from the batteries.
Inverter bypass is generally not a term I'd say is used for these portable systems. Its generally when you pass the load off to the grid. In this case, by passing the inverter would get you at best to the solar charge controller, which is DC power anyways.

all the USB charging stuff is probably just a step down transformer to 12V (for 12V accessories) and then 12V to 5Vfor usb.

It can possibly diminish service life, as each time you charge up and dip down its technically a cycle.

That said, small cycles like that aren't the worst thing, but doing it close to 100% SOC may not be healthy for it either.

EV cars use regen braking, its kinda the same thing. Little charges here and there.
Thanks for taking the time to explain that. I like the hybrid analogy!
 
i was wondering the same thing. I also order one with the idea that on occasion use it to charge my nissan leaf while simultaneously charging from solar.... i would charge it at home before i go camping and then set up the solar panels to charge at 700 watts while drawing roughly 1200 watts to charge the car. i would start the charging from solar form about 90% and charge right down til the ac200 reached 10% and then unplug my car and repeat... i hope it doesn't kill the battery to quickly
 
I like the MPP and Growatt All-in-one for the ability to "pass through". I was wondering if it wouldn't be a better match to use lead acid batteries, as they would be healthier fully charged the vast majority of the time. Or, would it be better to use lifepo4, and set it to charge to something like 60%, and discharge only to 30%? Is there a way to put the batteries in an optimal storage condition, and set the system to only charge/discharge once grid is out?

Also, I think I have heard of some of the portable "solar generators" having the "pass through" ability. Although you can charge the Kodiak while discharging, it doesn't really pass through as was demonstrated in the MPP videos Will has made. If the output of the Kodiak is > than the input, it will eventually be discharged and not work. Are there other "solar generators" that have the ability to charge from grid, while passing electricity through to an appliance, and then switching to batteries when grid is out?
 
The Ecoflow Delta is not a good UPS replacement because its inverter is always on and its battery is always topping off when it's being used in this way, which will degrade its NMC battery pack in the long term. From personal experience I can say that you'll be disappointed with the Delta's battery capacity. It will run a small window AC for maybe a couple of hours and it can run a full-size refrigerator overnight. It's a great unit for what it is but I wish it had an option for an external battery pack. (Connecting two units in series like they recommend doesn't count.)
 
Hello,

I'm looking to setup an all-in-one system for my shed to power some PCs and air conditioner, but I also want the all-in-one for power outages in the house (we're in California fire country), and camping.

I've got an order in for the Bluetti AC200, but am also considering the Delta Ecoflow.

I am trying to learn if it is "healthy" for the batteries to be simultaneously charged by a solar panel or a gas generator, while also discharging the battery to power things like my air conditioner or refrigerator.

Sometimes, solar (or gas) generation will exceed my output and I'd like to store the extra energy, and other times I'll need to utilize both battery and solar power simultaneously to power everything.

What I'm trying to learn:
1.
Is what I'm describing correctly called "pass through" charging, or an inverter "bypass"?
2. When I look at all-in-one specs, is there a way to determine if a product has pass through charging?
3. If a system does not have pass through charging, how much damage would I be doing to the battery if I do this daily? Instead of daily what if it was just during emergencies/ camping (20 days a year).
4. It seems odd some vendors would design a "solar generator" system to be charged or discharged at separate times-- am I missing something, or is this just an inverter cost cutting issue?
5. Between the EcoFlow Delta and the Bluetti AC200, would one system be better for this? It seems like the Bluetti has better battery cycle stats, but I thought I heard something about the EcoFlow having a bypass. Happy to do my own research, but if somebody knows off hand, I'd appreciate it.

I'm not willing to go for a full DIY system because I want the versatility to take it camping, etc. -- However, if there is some extra gear I could get in addition to the all-in-one to make this work in the shed, I'd be OK with it.

Thanks in advance for the help-
Solar_Shedquarters


Q/A from Bluetti AC200:
View attachment 16703
Hey I'm going through this same line of thinking at the moment. What did you find out? What did you go with and were you happy? Still going strong?

I'm looking at the Allpower R4000, The EcoFlow Delta Pro or maybe the Bluetti AC2000L.

Not sure what to land on yet.
 
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