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What's more important to AC200 - current or volts?

Luvnot

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Dec 15, 2019
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I have 4 x 100watt Rich Solar panels on my van roof (22.6 open circuit voltage, 5.4 amps) that will be used to charge a Bluetti AC200.
They are not wired yet because I'm trying to figure out whether to use parallel or series setup. Parallel will provide more consistent charges when the panels are in shade, but all of the sites say use series. Since the van is used on camp trips shade is going to be an issue.

The big question is, what's more important to charge the AC200? Amps or Volts?
PARALLEL: 4 panels x 5.4a = 21.6 amps
vs
SERIES: 4 panels x 22.6v = 90.4 volts
 
You need to read the manual and see what the maximum input voltage is. Exceeding this will let all the smoke out.

In either case, parallel or series, you have the same total power.
 
The big question is, what's more important to charge the AC200? Amps or Volts?
What's more important?
Maybe a fire extinguisher....What model AC200? The one with LiFePO4 battery or the LiPo?
 
The keyword to learn and remember is POWER (Watts) When you put (for example) two panels in parallel the voltage remains the same but the current is doubled. If you put them in series the voltage is doubled but the current remains the same, therefore your output power is the same whether you put them in parallel or series. I run my two panels in parallel to double the current and therefore double the power, but putting them in series would result in the same power. So really it is all about if your Bluetti AC200 can handle the voltage and current combination of either a parallel or series configuration. The benefit of a series configuration is that allows you to use smaller gauge wire to get the same power to your AC200. I learned this the hard way when helping a thesis student with his Solar Project. We measure the current being delivered to the load from the inverter and it was only 4 amps at 120VAC (480 watts) and without thinking I put a 30 Amp shunt between the battery and the inverter and just about fried the shunt because in order to get 480 watts from my battery I needed 40 Amps to the inverter. You need heavier wire in a parallel system than with a series system to get the same power. My specialty is measurement science, not solar systems so I have learned the hard way to keep track of battery power vs AC voltage power and the gauge of wire needed when deciding on a series or parallel configuration. So I guess that if your AC200 can handle either configuration series or parallel you just need to keep track of how many panels you can run in series and stay within the voltage range of your AC200. I personally prefer to stay within the range of the battery voltage requirements by keeping things in parallel but I understand that my charge controller will accept a series configuration...up to a point and that is where I turn into a chicken shit and stick with parallel. Hopefully some of the more experience members here can chime in and set me straight on a few things, I can certainly benefit from it.
 
You need to read the manual and see what the maximum input voltage is. Exceeding this will let all the smoke out.

In either case, parallel or series, you have the same total power.
True, but with a series configuration you can get away with smaller gauge wire from the panels to the AC300. Same power but less current with a series configuration due to the higher voltage. I suspect that the cables supplied with the panels can probably handle the current for either configuration, especially if there are only two panels involved. So then it becomes a matter of personal preference? I don't know.
 
What's more important?
Maybe a fire extinguisher....What model AC200? The one with LiFePO4 battery or the LiPo?
LOL, that was my first purchase when deciding to augment my home with solar power. Lots of folks forget that to get the same amount of power out of battery to supply an inverter with enough power to the load, the battery needs 10 times the amount of current and therefore 10 times more current rated cables. I bought a 4 pack dry chem extinguisher to handle my inevitable screw up.
 
I bought a 4 pack dry chem extinguisher to handle my inevitable screw up.

Possibly more serious.
You really do need to determine what chemistry the battery is made of. Until then assume it is Lithium ion and take extra precautions.

The makers of the Bluetti range of power generators really should display what type of battery is in the units and with appropriate warnings for the demography of people they advertise to!
 
Possibly more serious.
You really do need to determine what chemistry the battery is made of. Until then assume it is Lithium ion and take extra precautions.

The makers of the Bluetti range of power generators really should display what type of battery is in the units and with appropriate warnings for the demography of people they advertise to!
Good Point. I am running AGM batteries at the moment so I think (according to NFPA) the dry chemicals should work. I hear that Lithium Ion Batteries are a bitch to put out. Edit: Whoops, I also have a Lithium Ion portable power but apparently the good old ABC extinguishers will work on them as well. I should probably double check to make sure what I have are actually ABC type. Thanks.
 
Thanks for all the input! I purchased 20ft of 8AWG to run the approximately 15ft to the AC200, so I'm comfortable with the wire gauge.... and I definitely have a fire extinguisher in the van. Fire BAD :LOL:

The unit was purchased during the initial kickstarter program, so whatever the first chemistry is, that's what I got. I had to dig it out of storage, but looking at the label on the back of the unit it says input for PV: 35-150Vdc/12A max... hm.... So that looks like running all 4 panels in parallel would provide too much amperage (4panels x 5.4amps ea = 21.6amps). :(

I'm not sure how the math works for series+parallel. Would that give me 45 volts (series) at 11.6 amps (parallel)? If folks who are more familiar with the math for this configuration could verify the numbers, I'd appreciate the help.

I know most people are happy with series, but the weakness there is partial shading really killing the input. Parallel allows each individual panel to provide as much as it can without interfering with the others, but if the AC200 can't handle the higher amps, then I need to consider series+parallel. Any help with that math would set my mind at ease.
 
Thanks for all the input! I purchased 20ft of 8AWG to run the approximately 15ft to the AC200, so I'm comfortable with the wire gauge.... and I definitely have a fire extinguisher in the van. Fire BAD :LOL:

The unit was purchased during the initial kickstarter program, so whatever the first chemistry is, that's what I got. I had to dig it out of storage, but looking at the label on the back of the unit it says input for PV: 35-150Vdc/12A max... hm.... So that looks like running all 4 panels in parallel would provide too much amperage (4panels x 5.4amps ea = 21.6amps). :(

I'm not sure how the math works for series+parallel. Would that give me 45 volts (series) at 11.6 amps (parallel)? If folks who are more familiar with the math for this configuration could verify the numbers, I'd appreciate the help.

I know most people are happy with series, but the weakness there is partial shading really killing the input. Parallel allows each individual panel to provide as much as it can without interfering with the others, but if the AC200 can't handle the higher amps, then I need to consider series+parallel. Any help with that math would set my mind at ease.
Ah, yes....the higher current would be a problem if the input of the AC300 can't handle it, but...it could also be that it is incapable of drawing more than 12 amps so the solar panels would simply not provide it. The math is easy enough (I think) That 12 AMP max specification might simply mean that you can sock it with the maximum amount of it's voltage rating but it is only going to draw 12 amps to the internal batteries, no matter how much amperage your system is capable of producing. But if I am wrong.....Fire BAD!!! LOL.
 
True, but with a series configuration you can get away with smaller gauge wire from the panels to the AC300. Same power but less current with a series configuration due to the higher voltage. I suspect that the cables supplied with the panels can probably handle the current for either configuration, especially if there are only two panels involved. So then it becomes a matter of personal preference? I don't know.
If the unit accepts the higher voltage, then yes.
If not then you don't have much choice but to get the thicker wire.

Based on above it looks like series is probably fine.

You can resolve some of the shade issues with proper bypass diodes as well.
 
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