Charging from multiple sources

snoobler

Solar Honey Badger
One can have as many independent charging sources running concurrently as they like provided they are programmed properly for the voltage of one's battery bank.

Examples (some or all at once, even multiples of a single type, different brands, etc.):
  1. Solar PV via MPPT
  2. Solar PV via PWM
  3. AC-DC input via MPPT (using a AC to DC power supply feeding an MPPT solar controller with voltage/current consistent with a solar panel)
  4. Wind with suitable controller
  5. Grid/Generator AC via inverter/charger
  6. Grid/Generator AC via RV AC-DC converter
  7. Hydro with suitable controller
  8. Anything else someone might use to charge an off-grid energy storage system.
This is true for any battery chemistry.

Again, important that all chargers are appropriately configured to handle the battery bank with suitable absorption and float voltages.

Also very important that the sum of all charge currents do not exceed the recommended max charge current of the battery bank.


Note:
Multiple chargers only offer benefit when the battery is below the absorption voltage. Once the absorption voltage is hit, it is now a voltage limited charge and thus current will be lower than the sum of all sources. The battery bank will only accept as much current as it needs to maintain the absorption voltage. As the battery bank fills, current is reduced and chargers can no longer deliver current at the absorption voltage. They will drop out and go to float. Typically, the highest current charging source will always be the last source charging while all others are at 0A and likely in float mode.

Comments and corrections are welcome.
 
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C Subleski

New Member
How can I charge my Lithium battery using the cigarette charger in my vehicle?

I have an MPP Solar all in one unit with 600 watts of solar panels and a 24v lithium battery....but often when traveling on cloudy days my battery is not fully charged when I arrive at my destination 10 hours later and the sun is already down for the night.
 

rhino

Solar Addict
As a side note, I had a wind turbine charge controller and an Outback MX60 solar charge controller both charging same battery bank over the same 2/0 copper cables. This combination caused interference/noise with one of the controllers and had to run a separate cable to the battery for the wind turbine charge controller. So there can be some edge cases with getting multiple sources to all work with same bank :)
 

Freep

Solar Addict
How can I charge my Lithium battery using the cigarette charger in my vehicle?

I have an MPP Solar all in one unit with 600 watts of solar panels and a 24v lithium battery....but often when traveling on cloudy days my battery is not fully charged when I arrive at my destination 10 hours later and the sun is already down for the night.
Sounds like you need a DC-DC charger so your battery is charged up while you drive.
 

Dr Mark

Solar Enthusiast
I have my Growatt all in one set 28v bulk charge and 27.3v float charge but when its done charging my battery (from grid) the battery is around 26.6v. Does this seem right? I would think the battery would be above 27v at least. This is my first attempt at solar so I am unaware of what bulk and float are supposed to produce for the actual battery voltage when charging is complete. I do not have solar panels set up yet.
 

snoobler

Solar Honey Badger
Growatts are goofy. The bulk/absorption are for the solar charger only.

They don't have a bulk/absorption/float phases when charging from grid/genny - basically just terminates at the target voltage.


Utility/Generator Charger tips:
The generator charger is a different beast to the solar charger. (Does not utilize the Bulk and Float Charge settings)
It works on a float valve type principle. (triggers when battery voltage drops below that on setting 12 – set the voltage higher than current battery voltage to start charging right away)
Stops charging from Generator when setting 13′ s voltage is reached
Will not start charging the battery again until it drops below battery voltage – in setting 12.
Setting 01 set to SBU to activate setting 12 and 13.
Setting 02, is the Max charging current from Solar + Utility/Generator
Setting 11, is the Maximum Generator/Utility charging current @ your battery voltage (not at 120V)
Setting 14, make sure this setting includes the option to charge from utility/generator (see manual)
Note, setting Setting 11 too high for your generator may cause your generator to falter at startup, and cause the Inverter Charger to lose synchronization with the Generator (58 to 63Hz), if in doubt start small, and work your way up.


So you'll need to check setting 1, 2, 11, and 14. Set Setting 12 to whatever you want your minimum voltage to be - 24V for LFP or 24.2 for FLA/AGM/GEL. Setting 13 should probably be about 28V or whatever your battery's absorption voltage is. With LFP, that will get you to a very high state of charge, but with FLA/AGM/GEL, you'll only get to about 80% SoC.
 
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Dr Mark

Solar Enthusiast
Thanks for all the info. Reading it the user manual does not always stick. I realized that I had set 13 to 25V and was only focusing on the solar charger settings. I did not make the connection that there's an AC charger and the MPPT solar charger. I guess they both can charge at same time. I am going to AC charge again with the #13 at 28V. My battery is LFP and can be charged to 29 according to Evo. I seems that most of the capacity is between 25 and 27. I think you can tell by how fast the voltage drops if the load stays level. Ian helped with this with an email. He has responded to all my dumb questions. I made the attached file to remember the settings.
 

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Diysolar123

Solar Addict
How can I charge my Lithium battery using the cigarette charger in my vehicle?

I have an MPP Solar all in one unit with 600 watts of solar panels and a 24v lithium battery....but often when traveling on cloudy days my battery is not fully charged when I arrive at my destination 10 hours later and the sun is already down for the night.

first there is limit to how much power you can pull from a cigarette lighter outlet, make sure to check that.
If its a low power actual cigarette lighter output power will be limited. Some newer vehicles call them power outlets and they can actually put out some decent power; check first to avoid blown fuses and/or smoking wires.

as to charging things, you want what is called a buck/boost converter.
Buck converters take a high DC voltage and convert it into something at a lower voltage.
Boost converters take a low DC voltage and convert into a high voltage.

a buck/book convert can take in anything and produce anything within its maximum voltage and power limits, very handy!!
You can just buy board level devices, or
get it all in a nice package with something like an ISDT Q8 max which can take as input anything from 10v to 34v and produce an output voltage from 1 to 34v. You can give the Q8 12 volts and output 24, OR, give it 24 and produce 12, it is handy but pricey ($60-$80 depending on model).
Keep in mind your input power limits so you know how much current you can safely pull from the vehicle interface.
 

Ninjan8

New Member
How can I charge my Lithium battery using the cigarette charger in my vehicle?

I have an MPP Solar all in one unit with 600 watts of solar panels and a 24v lithium battery....but often when traveling on cloudy days my battery is not fully charged when I arrive at my destination 10 hours later and the sun is already down for the night.
Look at the Victron Orion Tr 12/24
 

OnTheRoadAgain

Solar Addict
One can have as many independent charging sources running concurrently as they like provided they are programmed properly for the voltage of one's battery bank.

Examples (some or all at once, even multiples of a single type, different brands, etc.):
  1. Solar PV via MPPT
  2. Solar PV via PWM
  3. AC-DC input via MPPT (using a AC to DC power supply feeding an MPPT solar controller with voltage/current consistent with a solar panel)
  4. Wind with suitable controller
  5. Grid/Generator AC via inverter/charger
  6. Grid/Generator AC via RV AC-DC converter
  7. Hydro with suitable controller
  8. Anything else someone might use to charge an off-grid energy storage system.
This is true for any battery chemistry.

Again, important that all chargers are appropriately configured to handle the battery bank with suitable absorption and float voltages.

Also very important that the sum of all charge currents do not exceed the recommended max charge current of the battery bank.


Note:
Multiple chargers only offer benefit when the battery is below the absorption voltage. Once the absorption voltage is hit, it is now a voltage limited charge and thus current will be lower than the sum of all sources. The battery bank will only accept as much current as it needs to maintain the absorption voltage. As the battery bank fills, current is reduced and chargers can no longer deliver current at the absorption voltage. They will drop out and go to float. Typically, the highest current charging source will always be the last source charging while all others are at 0A and likely in float mode.

Comments and corrections are welcome.

Correct me if I'm wrong, but I believe Kirchhoffs Law governs this electrical property.

I was reading up on that recently.
 

Charlie Woods

Solar Enthusiast
I am currently looking for a "Tri-Charge" solution for my Ham Radio go kit.

This would be a charge controller which can take electricity from:

* Solar Panels
* A/C 120v
* 12-volt DC-DC from a vehicle

...and reside inside my Go Box to charge a 20 amp hour LifePo4 battery there.

I don't believe such a thing exists.
 

rhino

Solar Addict
I am currently looking for a "Tri-Charge" solution for my Ham Radio go kit.

This would be a charge controller which can take electricity from:

* Solar Panels
* A/C 120v
* 12-volt DC-DC from a vehicle

...and reside inside my Go Box to charge a 20 amp hour LifePo4 battery there.

I don't believe such a thing exists.
It does exist! :) Jackery.com
 

Charlie Woods

Solar Enthusiast
It does exist! :) Jackery.com
Almost. :)

I do have one of these Nature's Generator brand "solar generators" which accepts input from Solar, Wind, and 120v AC.

I might be able to run 12 volts to my truck into the "wind" input terminals. More research is required.

I will probably swap the guts in this thing to run LifePo4 after the AGM battery it came with dies because I really like the wheeled-with-handle format for tent camping.
 

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