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SOC jumps or stuck


In few last weeks, there jumps up some problems in two of our installation.


1) 2phase - 2x Multi II 5000VA 48V, 9,6 kWh Lead-Carbon battery, 4,92 kWp, Smart Solar MPPT 150/85, Venus Gx

2) 3phase - 3x Multi II 3000AV 48V, 17,2 kWh Lead-Carbon battery, 7,2 kWp, Smart Solar MPPT 150/100, Venus Gx

these are not only installation with these batteries and we have no other problems, so I am certain, that the batteries parameters are set well.

there are 2 problems:

1) there are high jumps in SOC

2) once per 2-3 weeks the SOC stucks at some point and ESS stuck in float and system needs to be restarted to correct the SOC.

With our clients I have found out, that there is some weird behaviour, when the water pump or water level sensor (1) client doesn’t have water level sensor so it looks like, there is problem in water pump (230 V) which causing energy to returning to the system (it runs with the grid disconnecte). At the other client (2) I didn’t found problem in Water pump, but it looks like, the energy returns is caused by Water Level sensor.

Excuse my English please, I am better in reading then writing.

Thank You!

Stanislav Vávra asked
Stanislav Vávra commented ·

0 Answers

Multiplus-II Absorption and Float - discharging to grid


I have an ESS installation with a Multiplus-II 5000/48, an MPPT 150/85 with 4Kw solar system and a 48V 200Ah LifePo4 battery system (currently no BMS). Absoprtion voltages are 56.4 on the Multi and 56.8 on the MPPT - float at 54.4. There is some behaviour that is concerning me in that during absoprtion and float, the Multi seems to be continuously switching between charging and inverting, this happens during the day where the data logs look more complex due to varying AC loads and MPPT but it also happens during scheduled charging overnight, see plot below. You can see the half-hour absoprtion phase from around 00:20 to 00:50 where amps oscillate between +5A and -10A, then folllowed by a large amp spike (selling to the grid) at 00:50 when it switches to float (I believe this is caused by the drop in voltage - hence the battery needs to discharge current to achieve that. In float mode (from 00:50), the same behaviour continues, going from charging to the discharging.

I feel this is neither good for the batteries nor for the Multiplus - am I doing something wrong or areany of my settings wrong? I am running Mode 1 ESS self optimised.




tkrull75 asked

0 Answers

Float mode drops down below configured value


Suddenly my Smart Solar MPPT 100/15 has the following problem

The batteries goes up to 28.8V (Bulk voltage) goes to absorption (1A)

(2x12V lead acid batteries)

but applications shows me that goes only 0.2A to battery after some minutes goes to float which should be 27.2 but drops down to about 26.6 because the current for load comes from the battery... and after some second goes again to initial load and so on...

This is strange because the current for the load before came from the solar panel...

I have a 280W solar panel and load is only 85W when charging batteries 130W ....

So what could be the problem?

Defect batteries?

Batteries are normal auto batteries 75Ah each acid, calcium

Should I initialize an equalization cycle? (Never done until yet, they are about 4 month with this setup and 1 year in total use...

tkmbe asked

0 Answers

250/85 going to float 150/70 x 2 still in absorb

I just expanded an existing installation by adding a 250/85 to an existing system with 2 x 150/70 charge controllers . All wired up this afternoon, but the new charge controller is just sitting in float rather than charging as well. The old chargers are in absorb and the new addition goes straight to float, meaning the new array is not doing anything . Is there a fix for this ? One thought I had is the the 150/70s are using the adaptive charging ( which I cant change) and the new one I have set to fixed absorb time . The 250/85 didn't even run through its full absorb time before going to float

thanks in advance

JDM asked
JDM edited ·

2 Answers

How do you change the float voltage on an EasyPlus Compact?


The default float voltage on my EasyPlus Compact (12 volt, 1600 watts, 70 amp) is 13.8. This is too high for my LifeLine AGM batteries which require a float of 13.4 volts.

The float voltage can't be changed using the dip switches and the VE Configuration tools for VE.Bus Products software download that is available on the victronenergy.com web site only runs on Windows and I have a Mac.

Given the above, how do I change the float voltage?

Thank you

Allan Fraser

Allan Fraser asked
Justin Cook - Bay Marine Supply USA commented ·

2 Answers

Are these reasonable readings for a Multiplus SOC shutdown?

I went out of town for several days and after three unplanned cloudy days, the system shut down as expected. What wasn’t expected was the readings when I got home and turned on the generator to charge the batteries. The first image below shows what the status was when I first turned it on. As you can see, the SOC is 41% after about 15 minutes of turning the generator on.


I was wondering why it was floating if the batteries were at 41%. After 90 minutes of no change, I started looking into why the Multiplus was floating instead of bulk charging. I found a couple of messages in the Community that suggested switching it to “Charge only” as a way to reset the Multiplus. So I did and it switched to absorption mode (at 9:11pm).

Immediately after doing that, the next reading I got was 85% SOC. Literally five minutes later, I got the following: 100% charge and back to Float at 9:59pm, for a total elapsed time of 48 minutes.


So my questions are:

  1. Is it to be expected that a system that was shutdown due to SOC settings should go from 41% to 100% in 48 minutes?
  2. Was it some kind of hiccup in the system that I needed to change it to Charger Only for it to go off Float to Bulk and then Absorption charge?
  3. If this is abnormal, what do I need to do to get a better understand and control of this behavior?
  4. Are there settings I need to change?

The battery bank is eight 6v 385ah batteries in series/parallel at 24v.



Todd Landfried asked
kai commented ·

1 Answer

What settings should i put my charge controller on for a lithium ion battery

Hi all,

Quite new to this, hoping somone can help me with my set up

I have a 12v 50ah lithium ion battery

80w solar panel

75/15 bluetooth mppt victron charge controller

I am unsure on what the best setting is.

Thanks all!

Blake1 asked
pau1phi11ips commented ·

1 Answer

Can the 100/30 controller return to bulk from float in the same day?

Our 100/30 Victron MPPT controller NEVER returns to bulk during the day. We have three 2-month-old Lifeline 12V AGM batteries that have very little load on them. Cellphone charging, some water pump usage, and NO refrigeration. At the end of the day the voltage reads about 12.9 volts but not the float parameter of 13.8. The Victron controller is on the default preset setting of #2 which defines the absorption volts to 14.4 and float volts to 13.8. Why doesn't the controller sense that it should switch back to bulk during the day while there is still sunlight available? I realize that 12.9 is not excessively low, but can the controller enter back into another bulk stage?

EndlessSummer asked
klim8skeptic commented ·

1 Answer

Issues with BULK CHARGE not staying on. MultiPlus 12/2500/120 with Multi Control

Not so new but still good Trojan deep cycle 6 volt large battery bank (12 units),
Charging system:
Solar panels, micro hydro electric,
New Genset Honda 2200W Inverter connected to battery charger.

I can't get the charger to stay on "Bulk charge" like it should. The built in charger kicks off quickly to taper down to float charge way before the battery bank is not even close to be charged. It usually kicks off Bulk charge in about 5 minutes.

  • I keep the multi control setting at 18. (Could it be higher with 2200W genset???)
  • Solar panels/micro hydro seem to charge the battery bank no problem...

Possible causes of charger Bulk charge issues?

  1. My guess is the battery bank is getting old and I need to readjust the settings (INFO PLEASE...)
  2. Wrong charger settings? (INFO PLEASE)
  3. Bad connection? (checked everything)
  4. Faulty temperature sensor? (Checked connection) (Should I disconnect it for test?)

I disconnected the solar panel system and getting the same problem...

Thank you Victron. These units are amazingly durable and well built. This community page is well put together AND HELPFUL (I hope!). I will definitely get a new unit if this one ever gives up...

Patrick, Canada

Blackbox asked
Blackbox commented ·

1 Answer

Solar MPPT 150/45-TR suitable for tesla packs ?

Hi @all !!

it the above mentioned mppt charger able to charge a tesla pack in 12s Configuration ? Absorption should start at 49.2 Volts, Float 49.1 Volts.

I would like to add 90 Volts of Solar input voltage. Is that enough for the charger to work probably ?

Thanks a lot !


stxShadow asked
WKirby answered ·

1 Answer

Force a Quattro into Float?

Is there a way (switch, assistant, setting) that allows me to force a Quattro into Float -regardless of state of charge on the batteries?

I hope this hasn't been asked before, but search is not working at the moment (internal server error) so,

Here is my scenario, this deployment is in an RV.

I have a Quattro 24/5000/120 connected to a pair of 12V lithium batteries in series, with a BMV 712 monitoring them.

For half the year, this vehicle is spent "off grid", meaning no constant source of shore power (a generator is used to recharge the batteries).
In that scenario I manually manage the charge of the batteries to ~90% SOC (because evidence is showing it increases their lifespan over a constant 100% SOC). I do that by turning off the generator, and the batteries are allowed to discharge with regular day-usage. Then the recharge cycle is repeated.

That works great, however,

For the remaining half of the year, this vehicle is spent on-grid and has a constant AC input. That, of course, triggers the Quattro's charger functionality and it happily tries to recharge the batteries to 100% (with a *mandatory* and unnecessary 1 hour absorption as a bonus). And it repeats this cycle, anytime powerassist is triggered and the batteries are used temporarily (however little), thus discharging them enough to restart the whole cycle over and again.

I don't want it to do that :)

I believe that to be deleteriously burdensome on my batteries (or any lithiums for that matter), who would be much happier at ~50-60% SOC when operating in this "storage" mode.

And that's my issue.

I want to discharge the batteries to 50% and leave them there, while keeping the Quattro happily plugging along doing its other functions like passing power and power-assisting from the batteries as needed.

Is there a way to accomplish this with my Victron equipment?

I've tried a series of hacks to simulate this behavior. Primarily by using the charge rate assistant with an aux1 trigger switch. But even that, even though the assistant is set to 0 amps, when active, still isn't really 0 amps. It keeps a creeping 1.5 to 2 amps going, regardless - which eventually charges the batteries up anyway. Just slower.


Thanks in advance for your help.

Geomz asked
Mark edited ·

2 Answers

Constant .7 amp discharge from Quattro during float

I have a Quattro 24/5000/120 connected to a pair of 12V lithium batteries in series, with a BMV 712 monitoring them.

After the Quattro completes its absorption cycle, and goes to float, I am seeing a constant .7 amp “parasitic” draw that is being reported equally by the BMV and the battery BMS.

It starts almost immediately after absorption is complete and float starts. It shifts from 0 amps, growing to .7 over the span of a few minutes.

That draw will remain constant for hours/days without any action on behalf of the inverter/charger. Even if the battery SOC continues to drop (below 85% at last test).

That draw appears to be caused by the Quattro itself. I established that as follows:

1) there is no other 24V device in circuit. It’s just the Quattro, the bmv, and the batteries.

2) I shut off the Quattro and watched the load drop to 0 amps, as reported by both the bmv and the BMS. Turned it back on and watched it happen again.

Does that behavior make sense?

Is the Inverter supposed to generate a constant draw? I understand it needs its own internal power consumption, but assumed it would come from shore power -which is currently connected.

Will the Quattro at some point stop discharging and return to keeping the batteries, well, floated? Last time I let it get to 85% before forcing a bulk cycle (out of float) by triggering a (heavy) discharge.

The entire time the display on the CCGX just says float and idle.


This is not a grid tied system. Just an RV with 50 amp shore power.

I have rebooted/power cycled both the Quattro and the bmv and removed the batteries from circuit and put back in, for troubleshooting.

Thanks in advance for your help.

Geomz asked
Geomz commented ·

1 Answer

Why does battery charge state go into Float, even when my battery is low?

I have a MPPT 75/15 connected to 2 x 100W Flexable Solar panels, all powering my Renogy 12V 170AH Lithium-Iron Phosphate Battery. In the Victron app I'm using the battery preset for Lithium Iron Phosphate.

After a long trip away, my battery was very low (about 15% this morning) - I know this because I have a battery monitor.

At around 2pm today I when to check how charged the battery was, it was reading about 35%, but when I looked at the app to check solar charging, I noticed only 50W was being produced. My panels are in full sun. Then I noticed that the battery state on the Victron app was saying it was in Float mode, and was limiting the voltage to 13.5V.

I have a circuit breaker between my solar panels and charge controller, so I switched it off, and then turned it back on again, and now the battery is being charged in Bulk mode again at around 140W.

So my question is, why would the controller go into Float mode, when the battery is still low? How do I prevent this from happening again?

Thanks, Josh

joshseal asked
Inhabor commented ·

2 Answers

How to determine absorption/float/equalisation voltage

Hi guys

I recently bought myself a BlueSolar MPPT 150/35 CC to use in combination with a battery bank, consisting of 2x 6 V gel lead acid batteries (for golf carts): Golf Cart TAB Motion Gel Batteries (https://www.tab.si/index.php/industrial/display_smalltraction/4 ).

Now I ask myself the question how to determine the right determine absorption/float/equalisation voltage for this type of batteries. This link (https://chargetek.com/basic-information.html ) gives like a general rule of thumb for lead acid batteries: 2.25/2.4/2.55 V/cell ==> 13.5/14.4/15.3 V

I found there's a pre-installed program for forklift batteries: PzS tubular traction (1), 13.8/14.9/16.7 V. As forklift batteries are more or less similar to golf cart batteries and these numbers more or less look like the ones I found above, I intended to use this mode. However, I'm not quite sure if the batteries are tubular, and if that even matters.

Is there any other (experimental) way to determine these voltages?

Also, I read that it is not advisable to equalise gel batteries, is this right? Why not?

Thanks in advance!

mielke asked
JohnC commented ·

1 Answer

Float current with load on SmartSolar

Hi I searched but didn't seem to find what I am looking for.

I have a 75/10 SmartSolar, 50W panel, 35Ah Duracell AGM running a 12V industrial gateway (300mA draw).

So far all is working great I hooked it all up yesterday late in afternoon and got to absorption stage.

Overnight it was obviously drawing down and this morning it started in Bulk. Then went to absorption and now it has maintained Float for awhile.

But what I notice now is that while in absorption or bulk, the 300mA load would have been supplied by solar panel current. Now solar current is 0 (and I have sun) but battery is supplying all the current and matches what the load is. Now why would the controller convert available power to run the device vs making the battery do the work?


Peter Owens asked
Peter Owens answered ·

2 Answers

Boondocking with BMV-712: SOC error? Best practices?

I have the following setup: smaller 2015 Lance travel trailer with 2ea 12V lead acid flooded batteries in parallel, BMV-712 and the standard Honda 2kW generator. The trailer's battery charger seems modern (3-stage charging, lots of amps, etc.).

I plan to boon dock (no shore power) regularly and would like to tune the BMV-712 to help keep the batteries charged, healthy, and to know when and how long I should run the generator.

From research, I know I should always keep the batteries above 50% capacity to avoid premature replacement costs. Also, without many hours of charging (e.g., plugged in or on solar), I cannot expect battery capacity to rise above 90% while boon docking.

When charging from, for example, ~60%, the charger will be in the "bulk" mode with high current, and rising voltage. This charge mode is the quickest, but only gets to 80% capacity.

Then the charge mode changes to "absorption" where the charger voltage is held high (14.6v in my case) and then the amps fall off toward ~2amps (in my case) when the charge mode changes to "float" at which the battery capacity is at 90%. To charge from 90% to 100% capacity would take many hours and isn't reasonable while boon docking.

Therefore, while boon docking, I should expect to cycle the battery between 50% and 90% depending on loads and generator run-times.

However, AFAIK, the BMV-712 is designed to treat the 90% charge state as "100% SOC" (?) The BMV-712 decides that when the voltage is the high "absorption" mode, and then the current drops below a "tail current", it proclaims SOC = 100%. But in reality, the battery is at 90% capacity at that moment (i.e., at the end of the "absorption" mode).

If starting from a full-charge (i.e., batteries have been plugged in for a day), the SOC value will be fairly accurate. However, if not starting from a true full-charge (allowing the BMV-712 to auto-sync the 100% SOC value at the end of the absorption mode), the reported SOC value will be 10% lower than reality. So the accuracy of the reported SOC value depends on whether the previous charge completed the float mode? Is this true?

If that's true, then I must tweak other settings to make the SOC value match reality or add-in some fudge-factor or work-around.

I could:

  • tell the BMV-712 that the "battery capacity" is 10% lower than the battery specification.
  • set my "SOC relay (charge floor)" to 60% instead of 50%, and mentally never let the reported SOC value fall below 60%

Is this a known problem with the BMV-712 SOC value? What do others do to work-around this inaccuracy?

Do other boon dockers have tips on using the BMV-712 to stay confident that the generator is running for the right amount of time?


goodguy5000hd asked
ben answered ·

1 Answer

Float Voltage

I have a MPPT 75/10 with a PowerSafe SBS109F Battery (190aH 6 cell AGM)

The Label on the battery says the float voltage per cell is 2.29v @ 20 deg C and 2.27v @ 25 deg C

What float voltage and Temperature Compensation should I set in the charge controller?

REF5275 asked
WKirby answered ·

1 Answer

BMV manual info unconformity (!?)

I was reading paper version manual for my BMV today, just to review my setting and try to learn more about it. But I got confuse cause I think there is contradicting information within. I had to go check the online version, to check if it was a typo that was maybe corrected. But I find the same error (!?) in the online version of the manual.

I'm saying this, but I might be wrong and confuse, please correct me if I'm wrong. I would really like to know which info is right or if the 2 info I think are contradicting are just 2 different info that I think should be the same..

so at 2.3 commons problems it is mentioned:


and when reading further, at 4.2.1 Battery settings under 02. Charged Voltage we found that:


and then if you just the mentioned section 3.7 (in blue ^) the mentioned voltage (13.2v) is proper for float and not for absorb, so think section 2.3 is wrong, unless I am just really confused and those 2 pieces of information are not related to each other...

so to add to my confusion, when I look at my own setup in the BMV, charged voltage is set to 14,8V, which I don't remember having set that, but I would really like to know if this is right or not

If ever i am proven to be wrong, i would like excuse myself in advance since english is not my first language

Simonmtl asked
Simonmtl commented ·

1 Answer

Battery Voltage problem for Float / absorption


after asking a lot of persons , no one can give me a good answer so iam gone ask it here ;)

i've seen wierd thing going on with my system...

float is 55.20v , but the quattro doesnt stay on that voltage always some volts below it , 54.7v or 54.4v (in the beginning the 55.20v was good, but i dont remember the version of the firmware)

i have tested firmware 2.30 and all the beta's (now running Venus OS v2.30~51 )

i have tested with or without DVCC = same ( i need the "max. charge current" , because i have 10kw on the battery and only 95A can go to them )

i have the same problem for absorption voltage , it doesnt stay on 60v , always some volts below.

Here i have an other problem , the current does not go below 32A and stays putting 32A (or even ramps up the Current again) in the battery for the max. absorption time (6h)

i've been testing this for a long time and my battery is not broking for what the tests reveal, maybe its the way the battery works...?!?

absorption example :


All my mppts are like this ( also the values are the same for quattro ve.config)

i have 2x 150/70 and 1x 150/35


here you see the mppts try to go to the 55.20v :


My installation :


color gx - voltage of Shunt and quattro:



batteryExtra voltage meter:


above pics are for Float status

tests :

if i put value for absortion voltage to 60v (ve.config app) = quattro goes to 59.?v (does not stay at 60v)

if i put value for absortion voltage to 62v (ve.config app) = quattro goes to 61.?v

for that test iam sure my battery goes or can go to 62v

quattro values are always diff. from what the shunt tells me


quattro 8000-110A and mppts are the last firmware , color is last beta

battery 48v - 840ah


if you have some more questions i will give or will try to give you an answer , i must / will find my problem here :D

the one test i"ve not done, is reverse back to an older firmware for the quattro... (older than downloadable version)

thanks for reading this ;)


edit : added a screenshot from colorgx, so you can see there is enought pv power.. its feeding into grid a little


Kristof G. asked
Kristof G. commented ·

4 Answers

LiFe also too early to float


I have 6 X 100 amh LiFe from Battleborn. Connected to 945 W solar by the Victron MPPT 250/85 solar controller.

With average usage of little to 6 amps the batteries slowly drain as little time is spent in absorb and more in float.

Previous question was solved with heavier cable. I show only a 0.3 V difference between the controller and actual battery V with 2 AWG cable not more than 2 m.

The preset is on LiFe with absorb at 14.2 V and float at 13.5

Any suggestions are appreciated


SVMica asked
Paul B answered ·

1 Answer

Green LED (Inverter ON) to Orange LED (Charger Float)

I have a “Blue Power MultiPlus 48/5000/70 - Blue Solar Charge Controller – MPPT 150/35 - BMV 700 Battery Monitor. My system worked without ANY problems from, 24 Nov’18, until, 5 Apr’19 (131 days), throughout one of the worst winters in Crete, Greece. Since the arrival of beautiful sunny weather, a problem started. Green LED (Inverter ON) to Orange LED (Charger Float), since 5 Apr’19 until now 16 May’19 it has happened 8 times. Sometimes if I switch the Inverter OFF-ON it comes back on. Sometimes this solution takes Hours/Days. P.S. I have NEVER connected my generator Lowest Voltage = Zero, Highest Voltage = 58.2V I have 4 x 200Ah batteries ....

sorry it is taking me some time to navigate around

David Ohara asked
David Ohara edited ·

1 Answer

Multiplus on firmware 433 and 459 goes to float too early.

I have been running my Multiplus compact 24V 1600VA on firmware 159 for ages with no issues. I recently updated to firmware 459, restored the previous settings, activated the battery monitor option and input my battery capacity.

The first time after the update, the batteries charged fully and got to 100% capacity on the attached BMV. Subsequently, the batteries do not get fully charged before switching to float. The batteries charge to about 70-75% and then switch to float. The batteries keep getting about 9A charging current whilst on float showing that they are not fully charged.

Absorption was set at 29.4V and float at 26.04V.

I switched to firmware 433 but had the same issue. So, I am back on my original 159 firmware.

What may be the problem and how do I resolve it? Thanks in advance.

Rainbow Solar asked
Rainbow Solar commented ·

3 Answers

Phoenix 12/50 charger "Adjustments without remote panel"

I've just replaced a Quick SBC battery charger (which cooked my boat's house bank) with a Phoenix 12/50 charger. All straightforward, until I reached the section in the manual entitled 'Adjustments without remote panel'.

I thought I was buying a "Fully automatic adaptive battery charger", according to the blurb. Do I really need to make these manual adjustments?

The manual's description of the adjustment is poor and Googling hasn't helped. Can anyone shed any light? Anyone out there carried out this procedure?

[Note, my house bank is 4 x 150 Ah AGM batt's which I gather should have the max Bulk current dialled back a bit, hence wanting to follow up on this...]

Many thanks!

Harlequin asked
WKirby answered ·

1 Answer

absorption and float LEDS flashing simultaneously with no power coming from the panels

I have a MPPT 100/50 12volt Easy Solar system, not plugged into mains power and up until this morning i have had 4 panels charging my batteries. I've just put 2 more panels on and come inside to find the absorption and float LEDS flashing simultaneously with no power coming from the panels at all. All i can find about it tells me i have battery issues but since i just messed with the panels i find this highly unlikely. can any one help, i'm really stressed out at the moment as i don't know if I've damaged anything either

CoreyF asked
JohnC commented ·

2 Answers

What should I set Lithium Battery Absorption Time to?

They say that Lithium batteries don't need to be charged in absoption mode. I've heard that when charging Lithium you should go from Bulk straight to Float. Will setting the absorption time to zero achieve this? What about setting the absoption voltage to a really low voltage that is never achievable? What do others on this forum know of this? What settings do others use when charging their caravan Lithium battery? MPPT Bluesolar 100/30, Sentry 300AH Lithium, 300W solar.

RedRover asked
Evanjs commented ·

5 Answers

Help me understand the stages of the SmartSolar MPPT?

I'm a newbie to the fancy Smart controller that Victron provides, and I wonder if my charger readings and settings make sense. I'm also not real clear as to how the specs that Crown Battery provides correspond to the settings that Victron requires in their VictronConnect app.

From having read others' experience, I believe I have the settings right, but I'd like to understand their actual meaning!

My setup:

2-100W 12V solar panels in series

Victron Smartsolar 75/15 MPPT Bluetooth controller

Victron BVM-712 battery monitor plus temp sensor

2 Crown 220Ah GC2 6V standard FLA batteries in series

temperature 7°C

This is my understanding of the "bulk-absorption-float" cycle, please advise if I have it wrong...

Charging starts in Bulk mode, with max available current (up to 50A per Crown, but in reality current is limited by my panels to @ 13.2A)

The starting ''Voltage" in Bulk mode is determined by battery state of charge - and it gradually climbs to "Charged" level, which is equivalent to Absorption level (14.22V per Crown specs).

Once the SOC climbs to the "Charged" (Absorption) voltage-level, the controller switches to Absorption mode, which then limits the voltage to no more than the Absorption setting, and varies the current, gradually lowering the current, as the battery becomes more charged (as the battery accepts less and less). Question: does the controller actually keep the voltage at the 'Absorption' voltage-level (Crown calls it: 'Constant Voltage') during this Absorption phase?

When the charge current drops as low as 5A (per Crown specs) the controller should switch to Float mode (Crown: 'constant current'), and (should?) holds the current at 5A, until SOC corresponds to (controller setting of) Float Voltage (13.5V)? Question: does the controller actually stop charging at this point? ie: No 'trickle charge'?

Obviously, this last is one of my stumbling points. If Absorption Voltage is constant at 14.22V, then when the charger switches to Float mode, the battery voltage will read 14.22, won't it? In which case, 'Float' voltage will read high at this transition point? Or does the Absorption charging voltage drop as the SOC gets closer to Float?

So my confusion comes from Crown specs being unclear to me, and names of 'phases' and specifications not corresponding between VictronConnect, and Crown, and the Victron controller not having specified a 'constant current' for the Float mode

As I said, I'm new at this, and my Victron controller readings aren't following my understanding of the way it should work. For example, during the controller's Absorption mode (set at 14.22V in the app), the voltage will read 13.55V at 1.7A, which seems more like a Float to me. It's a cloudy day, but it seems it could be charging at 14.22 at 1.6A, per the Absorption app-setting. Or is this possibly the temperature compensation?

Ii appreciate any clarity anyone can give me on this!


harrycw asked
harrycw edited ·

3 Answers

Current flow in float charge.

What charge current should I expect in float mode? I have a 1040ah bank of AGM batteries, and when my solar controllers have switched to float mode, they draw around 8amps. Is this normal?

The solar controllers are in ESS mode, connected to a Multiplus, BMV-712 and Venus GX.

brokenlegg asked
JohnC answered ·

1 Answer


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