Portable Power Stations

Spizz said:
Ugreen is quality stuff. I’ve got a 65W USB-C/A travel charger that I swear by.
Click to expand...

Have one too but needed to get a McDodo 120W as 65W was not cutting it.

Actually sorry that is Unitek, have a 65W GaN Unitek for about a year for travel. Very nice.
 
Bundu said:
yes, I will definitely let you guys know if I experience problems with it.
I will be running heavier load tests and report back.
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Today I put a 3 bar heater on the UPS. Each bar is around 740W.
I disconnected the UPS from the wall plug and gradually switched each element in, to give total load of 2216W.
The UPS took it without a problem.
I then switched the wall plug and after about 5sec, the UPS tripped its Input, but the output stayed ON.
I switched one of the heater elements OFF, so the load was 1480W.
The UPS reset the wall plug Input automatically and was now charging again.
So all worked as expected, seeing the manual states that in pass-through mode, the output should not exceed 2000W.

I also measured the Output L/N, L/E and N/E - Voltages were 230, 120 and 110V
 
I have a question for the boffins here.....

The Geewiz UPS has an MPPT input for solar panels with the following spec 11.5-50V, 20A, 500W max.

What would happen if I connected a 24V 100Ah Lifepo4 battery to that input?
Would the UPS go up in smoke? Would it charge as if a solar panel was connected?

@wingnut771 @leon.davibe @Zuner and others
 
Bundu said:
I have a question for the boffins here.....

The Geewiz UPS has an MPPT input for solar panels with the following spec 11.5-50V, 20A, 500W max.

What would happen if I connected a 24V 100Ah Lifepo4 battery to that input?
Would the UPS go up in smoke? Would it charge as if a solar panel was connected?

@wingnut771 @leon.davibe @Zuner and others
Click to expand...
I think it would work or at least worth a squirt. Would be interesting to see what the MPPT does with 100A.

Link to this UPS?
 
Bundu said:
I have a question for the boffins here.....

The Geewiz UPS has an MPPT input for solar panels with the following spec 11.5-50V, 20A, 500W max.

What would happen if I connected a 24V 100Ah Lifepo4 battery to that input?
Would the UPS go up in smoke? Would it charge as if a solar panel was connected?

@wingnut771 @leon.davibe @Zuner and others
Click to expand...
Whish i was a boffin :)

I would reckon the item will charge as if a solar panel is connected the max amps of what the charge controller can handle

If trying it for the first time i would use a breaker to be able to cut the connection quick

i would think using a buck converter that can limit the current to not exceed the max amps specified. May also be a nice insurance


If the 24v battery bms has a adjustable max current draw setting it would be nice to set it to fall within the specs so that bms would switch off over current if the amps are exceeded

The problem for me is that the 24v100a will be able to supply 2400w before tripping

Normally it is ok to overspec the solar but ,No idea what it will do if you give it access to 2400w

Know i read on a different forum someone recommending a 20% oversize on an axpert mppt

My gut feel is to not try this without being able to limit the current
 
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leon.davibe said:
Whish i was a boffin :)

I would reckon the item will charge as if a solar panel is connected the max amps of what the charge controller can handle

If trying it for the first time i would use a breaker to be able to cut the connection quick

i would think using a buck converter that can limit the current to not exceed the max amps specified. May also be a nice insurance


If the 24v battery bms has a adjustable max current draw setting it would be nice to set it to fall within the specs so that bms would switch off over current if the amps are exceeded

The problem for me is that the 24v100a will be able to supply 2400w before tripping

Normally it is ok to overspec the solar but ,No idea what it will do if you give it access to 2400w

Know i read on a different forum someone recommending a 20% oversize on an axpert mppt

My gut feel is to not try this without being able to limit the current
Click to expand...
I'm more curious why you would use an R8000 battery instead of a R3000 PV panel.
 
leon.davibe said:
Whish i was a boffin :)

I would reckon the item will charge as if a solar panel is connected the max amps of what the charge controller can handle

If trying it for the first time i would use a breaker to be able to cut the connection quick

i would think using a buck converter that can limit the current to not exceed the max amps specified. May also be a nice insurance


If the 24v battery bms has a adjustable max current draw setting it would be nice to set it to fall within the specs so that bms would switch off over current if the amps are exceeded

The problem for me is that the 24v100a will be able to supply 2400w before tripping

Normally it is ok to overspec the solar but ,No idea what it will do if you give it access to 2400w

Know i read on a different forum someone recommending a 20% oversize on an axpert mppt

My gut feel is to not try this without being able to limit the current

Edit thinking about it a bit
A pwm charge controller essentially connects the solar to the battery for short stints the panel voltage gets dragged down to battery voltage not a big deal with panel but with a battery

it would be like jump starting a car with a 24 truck battery

So lots of current
With that big a difference in voltage lots of potential

May have been different with an mppt as it converts ie mppt solar charge controller is a massive buck converter essentially

But pwm NO
Click to expand...
Too many ifs and buts.
 
wingnut771 said:
I'm more curious why you would use an R8000 battery instead of a R3000 PV panel.
Click to expand...
As with many plans maybe just a question of having it already

I know when i had 2panels ie too low to start up my mppt i connected 2panels in series for 80voc and connected it direct to battery and just switch on the breaker when battery wasn't full or when load shedding again i had to be the charge controller too :)
 
Bundu said:
I have a question for the boffins here.....

The Geewiz UPS has an MPPT input for solar panels with the following spec 11.5-50V, 20A, 500W max.

What would happen if I connected a 24V 100Ah Lifepo4 battery to that input?
Would the UPS go up in smoke? Would it charge as if a solar panel was connected?

@wingnut771 @leon.davibe @Zuner and others
Click to expand...
50v voc strikes me as PWM not mppt, very sure it is mppt not pwm?

If pwm i would definitely not do it

As pwm just connects the panel to the battery in stints

So with that big a difference in voltage lots of amps is gonna flow

I would make double sure that it is mppt
 
leon.davibe said:
50v voc strikes me as PWM not mppt, very sure it is mppt not pwm?

If pwm i would definitely not do it

As pwm just connects the panel to the battery in stints

So with that big a difference in voltage lots of amps is gonna flow

I would make double sure that it is mppt
Click to expand...
Ah, so if it was a 12V battery then it's okay?
 
wingnut771 said:
I'm more curious why you would use an R8000 battery instead of a R3000 PV panel.
Click to expand...
if one lives in a flat where you can't use a PV panel, but have the capacity of a spare battery that you already own
 
leon.davibe said:
50v voc strikes me as PWM not mppt, very sure it is mppt not pwm?

If pwm i would definitely not do it

As pwm just connects the panel to the battery in stints

So with that big a difference in voltage lots of amps is gonna flow

I would make double sure that it is mppt
Click to expand...
the user manual says mppt, but who knows? That's why I'm scared to fnck the UPS up :(
 
Bundu said:
if one lives in a flat where you can't use a PV panel, but have the capacity of a spare battery that you already own
Click to expand...
then you just parallel that battery with the other battery and double your storage.
 
wingnut771 said:
Ah, so if it was a 12V battery then it's okay?
Click to expand...
that's what I was also wondering about. The UPS uses that same input for car charger, but car lighters are normally fused at 10A, so maybe I should try it with a 10A fuse?
 
Bundu said:
that's what I was also wondering about. The UPS uses that same input for car charger, but car lighters are normally fused at 10A, so maybe I should try it with a 10A fuse?
Click to expand...
If you use the car charger port then I see no issue. How will you charge the donor battery? Why not get a PV panel and sell the battery?
 
wingnut771 said:
Ah, so if it was a 12V battery then it's okay
Click to expand...
Not sure depends on SOC difference i would think


As they say if big difference in voltage you may see lots of amps for a short period of time

If the batteries are close enough it may have a current flow below the charge controller max
 
leon.davibe said:
Not sure depends on SOC difference i would think


As they say if big difference in voltage you may see lots of amps for a short period of time

If the batteries are close enough it may have a current flow below the charge controller max
Click to expand...
We have an LFP charging another LFP. Refer to offgridgarage for tests of what happens when attaching batteries with opposing SOCs.

I would be weary with a 24V LFP feeding a 12V LFP.
 
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