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Charging Lithium Batteries via EV charging point

Hi all,

i am being asked about this alot recently, some of our customers are using either 5 x 200ah 12v LiPo4 smarts in parallel or 3 x 200ah 25.6v Lipo4 Smarts in parallel to power their systems.

both use a quattro inverter / charger

now the question is, are we able to fit an external EV charger socket in place of the usual 16amp inlet, which would be connected to AC Input on the quattro to enable them to charge these batteries via an EV charge point on the go / at home.

thanks in advance

stevemarston asked
apple047 answered ·

2 Answers

Bluesolar Mppt 100/30 is not visible via VE.Direct

My mppt charger dissapears in the night, I am not able to connectc via VE.Direct cable, and it's always happenig when I disconnect the solar panels from device. What is the problem? Even no LED is ON in that moment.

marcello asked
marcello answered ·

2 Answers

Absorption Vs State Of Charge

Hi there.

A few disclaimers firstly:

I appreciate that SoC is not an exact science, depends a lot on chemistry and settings.

I have also ensured that the settings are such that the SoC doesn't switch to 100% too early

I have a 560aH flooded lead acid batteries (less than 6 months old) with 3 X MPPTs, SmartShunt and a Multiplus.

So heres my question:

I have read a number of Victron litterateur that absorption should start when the batteries are about 85-90% full. Where as on my SmartShunt, the SoC is often at 97-99% when Absorption starts. To put it into context, my usage is such that when my solar chargers start in the morning, I have used about 75aH overnight which is approximately 15% of capacity (again, I know there's no way of know that without testing). My SoC reads 87%. Perfect, about what you'd expect. The batteries are then charged during the day at about 7amps per hour for 10 hours. They then switch to absorption for the last 3 hours when SoC is is about 98% and go to float after 3 hours absorption. (3 hours absorption based on adaptive charging on my MPPTs).

So based on the above, I would assume that the SoC is working as expected, and my interpretation of "SoC=90% when absorption starts" is incorrect? Any ideas?


lawrence-craig asked
pwfarnell commented ·

3 Answers

Phoenix Smart charger goes straight to absorption


I have a Phoenix Smart Charger IP42 50A 1+1 that I am using to charge my lithium bank (not victron, DIY build).
My problem is that only minutes after switching on the charger, even if batteries are almost empty, the charger goes to absorption stage. The voltage (as shown in screenshots below) have not reached my set absorption voltage. The charger is not charging at max capacity, not is it charging at any constant voltage. The voltage changes slightly up and down. I don't see how this should be possible?



I really just want my charger to go full power constant current until my BMS system switches it of. I have set the absorption voltage higher in the charger than in my BMS. I do not want to use the supply function in the charger since I like the fact that the settings in the charger will protect my batteries should the BMS fail somehow.


Now the absorption timer kicked in and it transitioned to float. Dropping the voltage and charge current even more.... :-(

Still nowhere near absorption voltage I set...


smack asked
Jesse commented ·

0 Answers

Strange sound while charging new gel battery, is this normal?

I just installed a 330ah battery bank with three parallel 110ah 12V gel battery's. While charging, one of these battery's makes a strange sound. Like it is bubbling. When I noticed, the charger was at absorption stage at 14.3V and 6amps. Does this mean the battery is broken (or will get soon...)?

jdvt asked
jdvt answered ·

2 Answers

Need charging parameters for 12v 200 ah AGM telecom battery for Samlex EVO 4024 Inverter

I have 4 batteries connected for 24v 400ah bank, I need to know which voltage to use for a 50% discharge and 30% discharge, also which optimal float and charging voltage. If someone knows which charging parameters to use on that inverter, it will be appreciated.

edgardolugo asked
wkirby answered ·

2 Answers

Blue Smart IP22 Charger 1 vs 3

How does the 3 output behave with only one battery connected? Is the total charge output divided among the three outputs regardless? For example if only one battery is connected to the 3 output model would it get a 30 amp charge or a 10 amp charge. If the output is divided can all three outputs be hooked up to one battery?

joewwy asked
urban-mobile answered ·

1 Answer

Multiplus 12/1600/70 not charging at full rate

I just finished installing my multi and 280Ah of lifepo4 batteries with REC BMS. Everything else seems to work fine but I can't get multi to actually charge at 70A. It claims it's charging at 60-62A but when measuring with Fluke clamp meter it shows only ~50A flowing. Additionally my BMS shunt shows the exact same reading as fluke does so I'm betting that the Multiplus current measurement is nowhere near accurate...

How do I get the missing 20 amps of charging out of multi? That's quite a big drop from the expected value and increases significantly the charging time for a 280Ah bank..

I have the weak AC off, 70A set as the limit in the settings. Environmental temp is around 27-29C where batteries and multi are. Batteries were at around 70% when I started charging so they should be easily able to take the full 70A.

And to be clear the REC BMS is not communicating with Victron yet so that can't be the issue either.


Additional info as requested. Screenshots of the settings at the end of the message. During the screenshot I had set the device not to charge so I can make sure it's cooled and not doing anything for a while so when I flip the charging switch there can not be any issues with heat in the beginning at least. The environment is around 25C right now so even if it was slightly derating due to temp it should not be too many amps as per this doc

Multiplus firmware version 481 which should be the latest as no updates are available.

AC is grid AC right now so no limitations on that side.

Did a new test with no AC loads on at all and multiplus in charge only mode. Discharched the lithium battery to 30% so it's nowhere near full.

Voltage at victron end:13.5V

Voltage at battery terminals: 13.3V

Still Victron showing about 62A in victron connect but real amps about 52A. And victron is in bulk charge mode.

Additionally I'm able to easily pull 130amps from the batteries and with solar + multiplus able to charge at 80A. Smart solar MPTT has the same voltage levels as Multiplus as well. So definately seems that there's a problem with the multiplus...




Niko Järvinen asked
Alexandra commented ·

2 Answers

Charging speed difference?

Why is the charging speed different on the two marked boxes?

What can I do to fix this?


my-fair-lady asked
my-fair-lady commented ·

2 Answers

Victron Blue Smart IP22 Bluetooth Battery Charger setup for parallel batteries

Hi Everyone - I'm hoping you can help with a question I have on the best choice of AC>DC charger, and the setup for my planned battery configuration in my van build

At the moment I have three 95Ah AGM batteries that are hooked up in parallel that i want to charge using a Blue Smart AC>DC charger from my shore power system, and i'm wondering whether it's best to go with the 30A single output charger, with the pos and neg going to the batteries at the opposing end of the parallel bank, or potentially go with the 15A 3 output charger with each battery having its own pos connection and the neg's all running to a common bus bar? All options with fuses at the battery end of course.

Are there any benefits or drawbacks to either approach?

Does anyone have a similar setup to either option and can provide any good feedback on their choice?



kylec-03 asked
shreeyash answered ·

1 Answer

Blue Smart 12/30 IP22 skipping bulk charge

Victron Lifepo4 200Ah is currently at 3.13V per cell. Expected behaviour of the charger after switching it on: It should bulk charge the battery (LiIon-Mode enabled) with up to 30A and switch to absorption charge after the battery ist almost charged completely.

What the blue smart device does instead: It bulk charges for ~2s (yes, seconds...) and switches immediately to absorption charge for the next 2 hours with ~6A (decreasing over time). So the battery is never charged to its full capacity...

All parameters in victron connect app seem to be correct. 'Charged voltage' in BMS ist set to 14.0V, blue smart charges with 14.2V. Did I get something wrong? Any suggestion are welcome.

Florian Michel asked
wkirby answered ·

1 Answer

Multiplus 12/1600/70 relay clicks when AC shore power is connected not charging inverter works

Hello Phoenix Multiplus 12/1600/70 started to cut out on AC in 'charger only' setting connected to shore line. It started intermittently and I assumed it was voltage drop from shore post changed cables & input but no issues. The green light comes on for inverter and 230V sockets work from that but as soon as 16A shore plug is connected fan comes on then orange charging light briefly then relay clicks and shuts down the red thermo fuse no doesn't pop out???

I have 4x sealed Hankook 12v leisure DC batteries along with 600w solar to a 50A MPPT charge controller which was doing fine for 4+ years only recently with addition of 2x 500w smart radiators being installed if they were on at same time as fan oven the Multiplus fuse would pop out then reset when pushed back in. A guest on boat confessed to using an electric kettle which may of pushed past 1600w limit of the Victron could this of broken charger? The inverter still works I have tried pushing up the AC plug connectors to ensure a good connection anything else I can try internal fuse replacement?

Thanks in advance


peter-holm asked

0 Answers

mppt charge voltage set-point register 2001 ignored

translated version after the german version


ich habe inzwischen ein paar meiner laderegler in meinem 24V system aktualisiert.

leider hatte diese aktualisierung eine sehr starkt nebenwirkung: meine

steuerungssoftware kann die ladespannung dieser laderegler nicht mehr regeln.

heute habe ich einiges an versuchen gemacht, um eine loesung zu finden, leider

erfolglos. ich konnte zwar einfluss auf den betrieb der aktualisierten laderegler

nehmen, aber ich habe keine moeglichkeit gefunden, die ladepannung zu veraendern.

jeglicher wert im register 0x2001 (Charge voltage set-point) wird einfach ignoriert. es

ist mir lediglich gelungen, den ladestrom zu begrenzen, aber nicht die spannung.

es war mir auch nicht moeglich den wert des registers 0201 zu aendern.

abgesehen davon bekomme ich auch noch widerspruechliche statusinformationen.

im register 200e sind die bits fuer slave mode und externe kontrolle gesetzt und im

register 200f steht, dass der regler im stand-alone-modus laeuft und es kann ja nicht

gleichzeitig beides zutreffen.

ich habe mein programm extra mit einer moeglichkeit versehen, mir verschiedene

register uebersichlich als tabelle von allen ladereglern anzeigen zu lassen, um

herrauszufinden, warum die spannungsvorgabe ignoriert wird und dann einiges


dabei ist es mir zwar gelungen, die spannung, die vom laderegler als

batteriespannung, gemeldet wird, vorzugeben, aber das hilft mir auch nicht.

abgesehen davon will ich hier ja die spannung am batterieanschluss des ladereglers

wissen und nicht die spannung die ich vorgebe. auf den ladestrom hatte es

uebrigends keinen einfluss, als ich diese spannung auf 2 V unter der akku-spannung

eingestellt hatte.

habt ihr da einen bug eingebaut, der verhindert, dass die vorgegebene

ladesoll-spannung uebernommen wird ?

ich koennte jetzt natuerlich die einstellung der ladespannung fuer diesen laderegler

aendern, aber die einstellung wird ja immer dauerhaft gespeichert und ich weiß nicht

wie oft das moeglich ist. man soll flash-speicher und eproms ja nicht


als notloesung werde ich jetzt meine steuerung fuer diese laderegler mit einer

stromregelung erweitern in der hoffnung, dass ich bald wieder den strom ueber die

sollladespannung regeln kann. das ist naemlich wesentlich einfacher, da dann die

laderegler bei lastaenderungen an den wechselrichtern automatisch den ladestrom

erhoehen und das schneller, als die regelung.



in the meantime i have updated a few of my charge controllers in my 24v system.

Unfortunately, this update had a very strong side effect: my

control software can no longer regulate the charge voltage of these charge controllers.

today i tried a lot to find a solution, unfortunately

unsuccessful. i was able to influence the operation of the updated charge controller

take, but I haven't found a way to change the charging voltage.

any value in register 0x2001 (Charge voltage set-point) is simply ignored. it

I only managed to limit the charging current, but not the voltage.

I wasn't able to change the value of register 0201 either.

apart from that, I also get contradicting status information.

the bits for slave mode and external control are set in register 200e and in

register 200f says that the controller is running in stand-alone mode and it cannot

both apply at the same time.

I have given my program the option of giving me different

register to be displayed as a table of all charge controllers in order to

find out why the voltage specification is ignored and then some

tried out.

I managed to control the voltage from the charge controller as

battery voltage is reported, but that doesn't help me either.

apart from that, i want the voltage at the battery connection of the charge controller

know and not the tension that I specify. on the charging current it had

Incidentally, no influence when I set this voltage to 2 V below the battery voltage

had set.

have you built in a bug that prevents the specified

charging voltage is taken over?

I could of course now adjust the charge voltage for this charge controller

change, but the setting is always saved permanently and I don't know

how often that is possible. Flash memory and eproms shouldn't be used


as an emergency solution, I will now use my controller for these charge controllers with one

expand current control in the hope that I will soon be able to use the current again

target charging voltage can regulate. that is much easier because then the

charge controller automatically adjusts the charge current when the load changes on the inverters

increase and that faster than the regulation.


d-ferdi asked

0 Answers

PPP 40Ah charging via high capcity output

I have a few questions about Peak Power Pack 40Ah charging via high capacity output in car.

1. I've try to charge my PPP via this output and initially, about 2 minutes, the current were above 50 amps, and then gradually decreased to 30 amps. Manual says 15-20 amps max. Voltage from car's alternator is 13,95V, but voltage drop in cables (4mm^2) made effective charging voltage 13,3-13,6V.

2. 50 amps is above 1C charging. Is this safe for PPP, cells and for me? - fire, big bang etc.

3. Is the BMS still active and cells are protected? Is charging terminated automatically after PPP is fully charged?

4. Car/Solar input of PPP is limited to 7 amps, so charging takes 6-7 houres and often is too slow.

xylus asked

0 Answers

Tesla module charging voltage higher than cut off limits

Setup as follows..

1x tesla module

9x 330w mono perc panels

100/50 victron smart mppt

Smart shunt

Bmv 712


24v 5kVA multiplus.

I have been living off this system for two years now and have recently upgraded my array with 9 new panels.

We are just coming into winter in New Zealand and I haven't had this problem over summer.

The charging voltage is reading about .3 max higher than what I have it set to, to go into float and absorb mode. For example, I have it set to go into absorb at 24.3v for 6 hours and float at 23.35.. trouble is even with these settings it is charging up to around 24.6! It sets the alarms off and my relays. I have always had my absorption and float settings at around 24.4 and 24.5 respectively.. but I have had to lower my voltages due to risk of over charging my tesla module. Any ideas?

So far I have thought it might be a temperature issue, but I have read that temp compensation does not apply with lithium?

Or 2, my array is to big for my battery? I do notice that we charge A LOT more efficiently on a cold sunny day compared to summer.

I have just purchased the temp sensor for the BMV 712, but if my MPPT is already reading ambient temp in the same room as my battery, this won't solve anything. It never gets below freezing where I am in New Zealand, lucky to get a low of 5 degrees Celsius in the middle of winter.. and we haven't had many cold days this year so far, so I'm confused when thinking it might be a temperature issue other than the better performance of the panels...

jstone asked
JohnC answered ·

1 Answer

Absorption time should be settable to less than 1 hour with lithium

Currently my Quattro (and multi) only allows a minimum of one hour of absorption time on initial charge (even though it allows .25 hours on repeated absorption).

My (and arguably most) lithium batteries require very little absorption time. So forcing them into a 1 hour absorption is both unnecessary and potentially causes extra wear on lithium batteries.

I would like to see the base absorption time settable to, at the very least, the same levels as with repeated absorption, or to even smaller window sizes.

Ideally I'd put my batteries in 10 minutes of absorption.

geomz asked
carl-n commented ·

4 Answers

Victron EV Charging Station availability


This message is mainly for Victron staff.

I'm fully aware that there are already stations installed for end customers, mainly with the title of testing units, the question remains.

When this product will be available for general public?


cristimv asked
Daniël Boekel (Victron Energy Staff) commented ·

3 Answers

EEBUS support bei Victron

When will Victron support the EEBus protocoll. I have a Wallbox from VOLKSWAGEN (Elli) and want to do overflow charging.

Regards, Christian

chris-bs asked

0 Answers

Victron SmartSolar MPPT 20A 100V - setup questions

Hi All,

I am relatively new to campervan setups, and I do not have a background in 12v electrics.

I have had a Victron Smart Solar 20A 100V MPPT installed in my campervan together with a new leisure battery, which I am really pleased with on first inspection.

There are a number of options in the Victron Connect app to allow configuration of the Smart Solar 20A 100V MPPT, here are the settings I am talking about.


It looks like most of the settings (Charge Voltages etc.) are set by either selecting a Battery Preset (see options below), or by selecting "expert mode" and specifying your own numbers for the Charge Voltages. The "factory default" seems to be the Gel Victron Deep Discharge option.

The other Battery Preset options available are:



It says in the manual to ensure the settings match your specific leisure battery, and this is where I am struggling - I cannot seem to locate the information needed. The leisure battery installed is a 12V 110AH Xtreme AGM Leisure Battery (XR1750) NCC Class A.

So, my question are:

  1. Are the Factory Default settings ok for my specific battery? Or should I change them?
  2. If I need to change them, then:
    1. Should I pick another pre-set, if so which one?
    2. Or, should I use expert mode and set the Charge Voltages manually? And if I do, what numbers should I use?

A final (less important question) also

  1. What does the "equalisation stuff" do, and do I need to worry about it?

Thanks everyone!

monstreruk asked
tibo-huyers answered ·

2 Answers

can i configure my old dual Pheonix Multiplus 24/3000/70 inverter charger to charge Lithium Battery

Hi Newbie to this and forums in general.

I have an old generation Phoenix Multiplus 24/3000/70 dual or daisy chained charger inverter system on our boat. We have used it with 10x250AH lead acid batteries configured for 24VDC. I want to change these for lithium and want to know if i can get the inverter charger programmed to charge the lithium batteries. I am also looking at purchasing an electrodacus SMS0 in support of it if that helps in answering the question?



guy-odell asked
guy-odell commented ·

0 Answers

New victron agm battery accurate solar charging parameters
Hello I just bought a victron deep cycle 110 ah agm to replace the old battery after 3 years.
I would like to ask a Victron technician for the correct parameters.
I only use a solar charge with a fully configurable 30A mppt regulator.
Every day the solar energy is more than enuff to charge completely the battery. 
I discharge the battery every night on average about 20 ah.
I would like to know the correct absorption voltage and the correct duration of the absorption for my use (daily discharge of 20 ah).
Currently I have set 14.5v and absorption duration of 120 minutes with temperature compensation of - 4mV / C / cell. Floating 13.7v.
Today for example after the end of the absorption, the battery absorbed 0.8A in floating at 13.7V.
But trying to increase the floating to 14.5v, I saw that it went up to 2.6A. These is strange for me... 
Does that mean it wasn't fully charged? Or is it due to gas generation?
Then disconnecting the solar panel, after an hour the battery was at 13.5v, so it would appear to be fully charged.

The old agm, at the end of absorption, absorbed 0.8a for both 13.7v and 14.5v.
Why these difference on new battery? 
I can see all these parameters on the victronenergy smartshuunt.

francesco asked
francesco commented ·

2 Answers

IP65/IP67 Blue Smart Charger Low Current Mode

I am researching the IP65 12/15 charger. I see a nominal charge current of 15A and a low current mode of 4A. If I manually trigger the low current mode and then unplug it completely from both supply and load, will it "remember" it is in low current mode next time it is used?

If not, I assume I can plug it in and then set it to low current prior to hooking up the battery and before drawing power? Once it is manually put in low current mode, will it remain in that mode until manually set to normal current?

I ask incase I find myself with limited available current and want to ensure I remain fully in the low current mode.

Thanks in advance!

jake2664 asked
Matthias Lange - DE answered ·

1 Answer

Voltage Spikes, System Failure, MultiPlus Absorption Transition During Charging LiFePO4

System Design:

I have 3 Lion Energy UT1300 LiFePO4 105Ah batteries. They each have an internal BMS and are the 'drop in' replacements for deep cycle Lead Acid batteries. They are rated for maximum 100A charge / 150A discharge each and are connected in parallel using 4/0 AWG cables. On the negative terminal I have 12" 4 AWG cable to a BMV 500A shunt and then 24" 4 AWG cable to a Lynx Shunt. On the positive side I have 24" 4 AWG between the battery bank and a BlueSea m6000 disconnect switch, then 12" 4 AWG from the switch to the Lynx Shunt. The Lynx Shunt is connected to a Lynx Distributor. Then I have a MultiPlus 12/3000/120 connected to the Lynx Distributor via (2) 36" 4 AWG cables and a 400A Mega Fuse. The Lynx Shunt has a 800A CNN fuse. The MultiPlus has the voltage sense connected using a fused 20 AWG wire to the battery terminals. I know the 4 AWG wiring is not ideal, I will replace with larger wire in my final installation, I don't know if it is the source of my issue. Here is a crude wiring diagram



I can discharge the batteries fine, the problem occurs during charging. When the MultiPlus transitions from Bulk to Absorption problems occur. They range from interrupted charging (Absorption voltage set to 13.9 - 14.1) to complete shutdown of the MultiPlus (Absorption voltage set to 14.4 - 14.6).

Here is a picture of the PV during charging showing the transition between bulk and absorption. The absorption voltage is set to 13.9, the unit seems to stop charging after the transition to absorption.


Here is the picture of PV when the MultiPlus absorption voltage is set to 14.4 Volts. The drops during the absorption mode represent when the MultiPlus shuts down and then resets itself. During the shutdown all lights are off and AC1 is off. NOTE: The voltage spikes seem to follow the current peaks. The MultiPlus will continue this interrupt cycle indefinitely until I intervene.



1. Has anyone else seen this behavior?

2. Could this be caused by the BMS shutting down during charging?

3. Could this be caused by using 4 AWG cable?

4. Could the MultiPlus design be causing the voltage spike?

5. What would a normal PV chart look like during absorption mode? I have read absorption mode is a constant voltage with reducing current until charging is complete.

Thanks in advance for any help.

mtnscott asked
davesnothere commented ·

4 Answers

Chargeur IP22 qui laterne BULK / ABS en permanence

J'utilise un chargeur Victron IP22 30A pour ma batterie Lio-ion. Quand il est alimenté, au lieu d'une charge constante à 30A je constate plutôt un temps de charge de plusieurs secondes (avec un grésillement, en bulk) puis une phase calme (sans grésillement, en absorption). Jusque là ça paraît normal.

Sauf que le cycle reprend une minute plus tard et ainsi de suite, avec très peu de consommation, ça ne peut pas être une décharge rapide qui ferait re-venir dans en bulk en quelques secondes. Surtout qu'en absorption, le chargeur délivrera le courant absorbé par la batterie et les consommateurs, donc elle ne se décharge pas (tension fixe).
Voici quelques screenshots de l'app Victron, avec l'heure du téléphone pour la séquence.





Une idée de ce qui se peut se passer ?


Bruno Bruno asked
Bruno Bruno commented ·

4 Answers

Feature request: Dynamic Grid-Setpoint in ESS, based on top SOC.

Currently the Grid-Setpoint in ESS is a static number (in watts) that controls how much system power is allowed from grid, with the remaining load being served by incoming solar and/or battery capacity, down to a tolerable SOC. While that works great in the assumption of keeping batteries @100%, every day, it’s not so good for long-term health and maintenance of lithium batteries, in a (stable) grid-tied system.

I would like to suggest an upper limit to the SOC (other than default 100%), at which point the ESS would dynamically shift the load more/less (by changing Grid Setpoint) to charge the batteries when they’re below the high mark, and otherwise running the load off of solar or battery capacity, down to the existing minimum SOC (as normal)... or similar type of functionality.

Currently, I’m constantly changing the Grid Setpoint down, to serve the system loads from the incoming solar preferentially, as much as possible. Then resetting it up again at night, to keep the batteries above a reasonable SOC. While workable, it is way more manual than it needs to be.
I believe adding a simple top SOC to the algorithm that controls when to shift to using solar would greatly simplify and automate this process.

geomz asked
Alexandra commented ·

0 Answers

IP22 charger cycling between BULK and ABSORPTION too quickly


I'm charging a 250 AH li-ion batterie equipped with an internal BMS.

When connected to mains, the charger start in BULK charging at 30A, and quickly switches to ABS (around 3A, which is correct).

But a few dozen of seconds later, it goes back to BULK charging at 30A, and a minute later back to ABS, and cycles like this.

Load on the battery is light at this time (around 10W), and from my understanding, ABS should maintain a fixed voltage and provide the current absorbed by the battery (+load). No reason to switch back to BULK charging.

I see alternating BULK (buzzing) /ABS (silent) every minute. I'm providing four screenshots of the app with phone's time to illustrate.





Any idea on what could be causing this ?

Thank you !

Bruno Bruno asked
Bruno Bruno commented ·

3 Answers

Charging current advice needed


I have a BlueSolar MPPT 100/30 charger and 2 used car batteries (12V, 60Ah), Varta, no maintenance needed (sealed), which I want to put in series so I can have a 24V system.

I see in VictronConnect that I can set the charging current .. but what value should I put there to be safe?

I plan in using the batteries mostly as a buffer system (a 24V, 300W pump is running to move the water from a deep well to a water tank).

Thank you!

sorin-t asked
sorin-t commented ·

1 Answer

Smart solar throttling bulk charge


i have Smart Solar 75/15, which appears to be throttling or reducing the charge during the bulk phase.

I have 2 solar panels, a 130w panel (open circuit voltage 18.2v, and short circuit current of 7.2A) and a 100W panel (open circuit voltage 18.6V, and short circuit current of 4.9A). These panels are connected in parallel. The solar controller is connected to two brand new AGM batteries 92Ah and 120Ah connected in parallel. There are no loads on the batteries.

The highest output shown on my 75/15 is just 112W. The screen shot below shows just 66W with the battery at 14.43 v. This was in the middle of a sunny clear day in Australia, and just before I tested the panels with the multimeter. The Adsorption voltage is set to 14.8v. My understanding is the 75/15 should put in as much current as possible during the bulk phase. With my panels, I should see a Max of about 220W.

With no real load on them at the moment my batteries start at 12.7v in the morning. With the throttling behaviour of the solar controller, they seem to take ages to get up to the bulk/adsorption trigger voltage of 14.8 (which temp compensates to 14.61v). In the snip below it took 3 hours 42minutes to reach this voltage, this was in full sun from 10am!

Could someone please explain what is happening. I’m disappointed in this solar controller, as it seems to not be using the full potential of the panels, and so take ages to raise the battery voltage.






danialan asked
klim8skeptic commented ·

4 Answers

Cyrix or FET diode bridge ?
Hi everybody,

I am in the process of upgrading my boat from a single battery to separate battery banks. I have a few questions about that.

1. what / which technology is best to use and connect to charge both banks with the chargers (shore power, alternator, wind and solar).
2. I have been looking for Cyrix and FET Diode bridges and do not know what is best and how to connect. And if a Diode is a 1 way system how do the chargers know when they are full.
3. What are the best universal settings for AGM batteries if I want to set the BMV712, Smartsolar and shore power charger. Now I notice that my old lead battery is not yet full according to the charger, but the BMV gives 100% and keeps bulking for 30min.

all tips and help welcome :)

greetings Ian



ian-macleod asked
ian-macleod edited ·

0 Answers

Pylontech US3000C Charging Characteristics

Good day all,

It is my first time installing a 3000C pylontech battery, and the charge curve looks very different to the US2000B I have installed before. The settings are all correct and the device is happy, the only thing I can think of is that the battery BMS is not asking for current, which is different to my us2000B installation...

Any one else seen this? I assume it is normal as the system works flawlessly, just very odd.



Side note- I did use a type A cable and not a type B cable as per the updated Can bus communication report

ewalderasmus asked
checkit answered ·

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