Charging from multiple sources

[Goboatingnow]

In general you can happily parallel charge sources assuming each charger has settings appropriate to the battery being charged.

 

[Capt Bruce]

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.

Have you considered, using some of your vehicles alternators current to charge? (assuming it is not electric)

 

[samv76]

any advice on a solar + wind charger that can handle Li-ion chemistry? Im still fairly new to this but most of what i read is that those mppt chargers come with charging caracteristics for LifePo4 battery chemistry. So i guess i would need a charger where i can manually specify the charging caracteristics for my battery pack.

 

[Nadad]

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.

Best Price 24V Growatt SPF 3000TL LVM – 3kW 120Vac Stackable Inverter 2kW MPPT Charge Controller Split Phase 120V/240V capable with two or more units – Special – Watts247 Wholesale

watts247.com

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.

Good day please, are there charge controllers that charge with generator/public utility power supply?

 

[GooseF16]

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.

DC to DC charger direct to the battery . or if the voltage enable is low enough, you can plug the cig lighter into the second MPPT port directly.. or a DC Boost power supply. A cig lighter is good only for 100 to 200 watts though without blowing. I have read where some people use a DC to Boost 12 to 24 or 48v and plugged that into the solar input of their Delta Pro for example..

 

[Hedges]

Good day please, are there charge controllers that charge with generator/public utility power supply?

Battery chargers. Most are meant for temporary use recharging automotive or forklift batteries, so difficult to get the right voltage and regulation.

There are inverter/chargers. Some stop inverting and pass through grid to loads while also charging battery (common mobile units for RV). Some are grid interactive, synchronize inverter to grid and draw just some power from grid. Some have built in battery chargers powered from grid, and output is always from inverter.

It may be possible to feed utility grid into "PV" input of some charge controllers. That would be an electrical design project - probably isolation transformer, rectifier, and need to limit inrush current charging capacitors.

A better way to do that could be an AC to DC power supply (or 48V battery charger) connected to the input of a charge controller which has suitable profile. Probably not "PV" input, but one that has "turbine" input settings. Outback and Midnight have such SCC.

 

[Nadad]

Battery chargers. Most are meant for temporary use recharging automotive or forklift batteries, so difficult to get the right voltage and regulation.

There are inverter/chargers. Some stop inverting and pass through grid to loads while also charging battery (common mobile units for RV). Some are grid interactive, synchronize inverter to grid and draw just some power from grid. Some have built in battery chargers powered from grid, and output is always from inverter.

It may be possible to feed utility grid into "PV" input of some charge controllers. That would be an electrical design project - probably isolation transformer, rectifier, and need to limit inrush current charging capacitors.

A better way to do that could be an AC to DC power supply (or 48V battery charger) connected to the input of a charge controller which has suitable profile. Probably not "PV" input, but one that has "turbine" input settings. Outback and Midnight have such SCC.

Battery chargers. Most are meant for temporary use recharging automotive or forklift batteries, so difficult to get the right voltage and regulation.

There are inverter/chargers. Some stop inverting and pass through grid to loads while also charging battery (common mobile units for RV). Some are grid interactive, synchronize inverter to grid and draw just some power from grid. Some have built in battery chargers powered from grid, and output is always from inverter.

It may be possible to feed utility grid into "PV" input of some charge controllers. That would be an electrical design project - probably isolation transformer, rectifier, and need to limit inrush current charging capacitors.

A better way to do that could be an AC to DC power supply (or 48V battery charger) connected to the input of a charge controller which has suitable profile. Probably not "PV" input, but one that has "turbine" input settings. Outback and Midnight have such SCC.

thanks for the response. though my post was in error as I meant the normal battery charger as you indicated the first paragraph of the response. However, I will need some guidance on the possibility of equalizing a 12v 220ah flooded tubular battery with a 600w array and a 60amp charge controller.

 

[Nadad]

Here are the S.G values of the said battery:
Cells;
1) 1.245
2) 1.275
3) 1.275
4) 1.270
5) 1.260
6) 1.250

 

[Hedges]

2640 Wh battery, 600W would be 0.223C and 50A.

For normal charging, FLA might want 0.12C (check the manual).
I think orienting PV panels multiple directions could reduce peak current an sustain 0.12C for more hours.
SCC hopefully can be configured for a target maximum current, e.g. 26A if 0.12C is desired.
Some can use a shunt to regulate battery current while supplying additional current for loads like inverter.

The question is what voltage and current should be used for equalization. Sunny Island has default 2.50V/cell, adjustable 2.3V to 2.7V and default 10 hour cycle (page 169). See if you can find a manual for your battery. I don't know how much current is required.

https://files.sma.de/downloads/SI4548-6048-US-BE-en-21W.pdf

For old, tired AGM batteries (which aren't normally supposed to be equalized, but what do I have to lose?) I follow parameters in the following manual. First charging at 14.5V, then equalizing at 15.5V (a bit higher than the 15.0V default for FLA). I think it draws about 1.0 A for a 100 Ah battery.

http://sunxtender.com/pdfs/Sun_Xtender_Battery_Technical_Manual.pdf

 

[ljwobker]

So this thread is great, thanks. My question is what happens if/when you have multiple chargers that are set for different battery types or profiles? One of the chargers I have the manual for has two "AGM" battery settings, "AGM1" is 14.1/13.4v, and "AGM2" is 14.6/13.7v.

If I were to wire up two of these chargers with different settings to the same battery (or the same group of parallel batteries...) what would actually happen? (and to be clear I realize it's dumb, I'm trying to understand how it works...)

I read above where the chargers can't act as a current sink, which (sort of) makes sense to me, but I'm also looking at my picture here and what I see is a pair of battery chargers wired together to each other, which seems kinda like a bad idea?

Assuming these chargers basically "ignore each other" -- I **think** that what will happen here is just a function of the four different voltages, right?

1. less than 13.4v, behavior 1
2. between 13.4 and 13.7v, behavior 2
3. from 13.7 to 14.1v, behavior 3
4. from 14.1 - 14.6v, behavior 4
5. above 14.6 behavior 5 (I'm pretty sure I know this one: nothing happens!)

or... maybe not?

 

[jakew009]

So this thread is great, thanks. My question is what happens if/when you have multiple chargers that are set for different battery types or profiles? One of the chargers I have the manual for has two "AGM" battery settings, "AGM1" is 14.1/13.4v, and "AGM2" is 14.6/13.7v.

If I were to wire up two of these chargers with different settings to the same battery (or the same group of parallel batteries...) what would actually happen? (and to be clear I realize it's dumb, I'm trying to understand how it works...)

I read above where the chargers can't act as a current sink, which (sort of) makes sense to me, but I'm also looking at my picture here and what I see is a pair of battery chargers wired together to each other, which seems kinda like a bad idea?

Assuming these chargers basically "ignore each other" -- I **think** that what will happen here is just a function of the four different voltages, right?

1. less than 13.4v, behavior 1
2. between 13.4 and 13.7v, behavior 2
3. from 13.7 to 14.1v, behavior 3
4. from 14.1 - 14.6v, behavior 4
5. above 14.6 behavior 5 (I'm pretty sure I know this one: nothing happens!)

or... maybe not?View attachment 127019

Having them set at different voltages doesn’t do anything bad. It just means that one charger will eventually be sat there doing nothing whilst the other charger finishes charging.

Whilst both charges are current limited, it literally makes no difference at all.

 

[Nadad]

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.

Good day, please I need help. I have a 30amp. Pwm Charger (not charge controller). How can i bypass the pwm mode to enable me equalize my lead acid batteries?

 

[Rednecktek]

Good day, please I need help. I have a 30amp. Pwm Charger (not charge controller). How can i bypass the pwm mode to enable me equalize my lead acid batteries?

If the unit doesn't have a pre-programmed equalization program, there's no way to do it. A PWM charger can still equalize, it just needs to know how to do it in the firmware.

 

[curiouscarbon]

Good day, please I need help. I have a 30amp. Pwm Charger (not charge controller). How can i bypass the pwm mode to enable me equalize my lead acid batteries?

Sorry to inform you, but @snoobler is no longer on this forum. Thank you

 

[Aly_Oops]

If using Victron system, it has a setting in DVCC that would share voltage, temperature, manage battery charge voltage, set max charge current, etc. It will control the battery but allow any extra current to be used by other loads, like ac. Work great. I would think there are other system, but I am not aware of any at this time. ( I never looked, lock on to Victron right away). I am using LifePo4 which has bms, so more options. I would think AGM would all be the same setup required.

I only have 2 AGM for my diesel truck and only a victron solar unit with 200 watt panel. Keep it top up when parked for period of time.

 

[sunshine_eggo]

If using Victron system, it has a setting in DVCC that would share voltage, temperature, manage battery charge voltage, set max charge current, etc. It will control the battery but allow any extra current to be used by other loads, like ac. Work great. I would think there are other system, but I am not aware of any at this time. ( I never looked, lock on to Victron right away). I am using LifePo4 which has bms, so more options. I would think AGM would all be the same setup required.

and FLA and GEL.

I initially used DVCC on my FLA bank. 4S2P Trojan T-1275. They were limited to .13C charge or 39A. Array was capable of > 50A, so I used DVCC to limit current to the FLA but had the extra for loads.

DVCC also allows my Batrium to prohibit charging of the Lithium bank between 1 and 7°C through BMS control It permits PV power, but restricts battery current to 0A. Below 1°, Batrium triggers critical fault and disabled MPPT completely.

 

[JeepHammer]

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.

That's as accurate and succinct as an amateur/layman can get without a ton of $30 words and a master's degree.

Over the past 10 years with Lithium batteries I've had to educate myself with 'C Rate' (Coulomb Law Rates).

It's about Time & Amps dumped (into or out of)

Basically, if you have a 100 Ah battery, and you charge or discharge it at 1C, that's charging or discharging 100 Amps per Hour.

Most of the Lithium I've had can dump amps faster than they charge, sometimes 4X or 5X faster.

If you have 100 Ah battery and you charge at 50 Amps, it's going to take 2 hours (hypothetically), and that's a 1/2 C Rate.

Ideally, I try to keep charge/discharge to 0.2 C ... I like BIG battery banks off grid, and charging at .2 C means full charge in 5 hours of peak sun.

 

[tlc]

.

 

[JeepHammer]

So this thread is great, thanks. My question is what happens if/when you have multiple chargers that are set for different battery types or profiles? One of the chargers I have the manual for has two "AGM" battery settings, "AGM1" is 14.1/13.4v, and "AGM2" is 14.6/13.7v.

If I were to wire up two of these chargers with different settings to the same battery (or the same group of parallel batteries...) what would actually happen? (and to be clear I realize it's dumb, I'm trying to understand how it works...)

I read above where the chargers can't act as a current sink, which (sort of) makes sense to me, but I'm also looking at my picture here and what I see is a pair of battery chargers wired together to each other, which seems kinda like a bad idea?

Assuming these chargers basically "ignore each other" -- I **think** that what will happen here is just a function of the four different voltages, right?

1. less than 13.4v, behavior 1
2. between 13.4 and 13.7v, behavior 2
3. from 13.7 to 14.1v, behavior 3
4. from 14.1 - 14.6v, behavior 4
5. above 14.6 behavior 5 (I'm pretty sure I know this one: nothing happens!)

or... maybe not?View attachment 127019

The only issue I see (from experience) is one charger with lower top voltage cut out.

This isn't particularly a bad thing.

When I use more than one charger on a battery, the load (charging battery) will demand amps, pulling voltage down, everything runs along swimmingly.

As the battery demands less, voltage rises to above the upper threshold of one charger, and it shuts down, exactly what it should do.

Usually the battery is well within the Amp load of the second charger and just final top off charging anyway, so no big deal.

Where I sometimes get into trouble...

Not checking EXACTLY where the cut off voltage is. I like a little differential so they 'Cascade', or shut down in sequence as the battery reaches top charge.

Having EVERYTHING blink On/Off if they are all the same is an issue when they all have exactly the same cut off voltage...

That's a lot of cycling surge load on my system... Little steps between the shutdown voltage keeps that from happeneing.

 

[TimE]

We charge our marine lithium bank in the following way;
Solar via a single Victron MPPT
Wind turbine via a dump type regulator/ resistor
Ditto hydrogenerator
Victron B2B from engine battery when engine is running
Diesel genset via a pair of chargers giving up to 100amps output
Most of the time to solar and wind do everything