BB 1230 battery Charge

[Franco De Mei]

I have some problems with Charging process, but I don't understand if is due to a Battery Charger BB1230 (Sterling Power) 

As the BB is switched on, the charging process start, I can read charging current +/- 30 A  until the battery is charged. Once SOC reach 100%, on page 3 of SBMS0, I see that "C FET" that go off , "EOC" go on,  after a while, also"0V" light on. EXTIO 4 go off switching off BB1230. Until now system work fine.   When the BMS0 decide is a time  to restart the charging process, it close EXTIO4  then BB1230 start again to charge the battery, at the beginning the charging current is close to 30A but slowly slowly drop down, until the read current is more or less the load current. The SOC reach 100% but this time CFET is all time on and EOC  is all time off. If I reset BB1230. the charging process restart normally until next cycle. Is this  normal charging process or something is wrong ?

[Dacian Todea]

Franco,

What is your load ? What current for the Load?  Are you sure both current shunts are set correctly (assuming you use both). It may be that BB1230 enters for some reason in constant current charging tho that should not be the case if you left the LiFePO4 battery settings as default 3.55V of overvoltage and did not changed anything else.  Longer wires from BB1230 to battery with some significant voltage drop may also contribute to this and another problem may be that BB1230 limits the current as it heats up in order to protect itself or maybe the alternator overheats and limits the current if it has some sort of thermal protection.

[Franco De Mei]

Hi Dacian,

 The current load is very low, normally, to the pier, I have the spot light consumption and fridge , when the pump running, no more than 6 amps. The shunt polarity is OK. On a SBMS0 Display, page 6, I see the current flow from PV to the load. ex. if the PV current is 1.5 A , to the load, I can see (more or less) 1.3 amps flows to the Load and the rest to the battery as current charge. the BB1230 it should be settled for Lithium battery chemistry (LiFePo4 Led On), therefore it should be in constant voltage. but strange , When I switch on bb1230 until the SOC doesn't reach 100% and SBMS switch off  CFET  I have max charging current. in the next charging cycle, the charging current is to the max then drop down, On a BB1230 LiFePo4 led switch off, absorption led  light on, after a while Float leg go on.  ( i don't understand if is regolar or not) next week I can Make  small movie with some pictures to explain better whats happen.

[Dacian Todea]

How long is the DC cable from charger to battery ?  and what cable thickness?

You did not mentioned if you are using the default SBMS0 settings.

https://www.youtube.com/watch?v=EgrhgD822ZM

[Franco De Mei]

From charger to the battery the length  is not more the one meter. I used cable 50 mm2 thickness, I used SBMS0 default settings. I changed only the capacity value (To 310 ah) and shunts settings. I know the video to YouTube . I Have BB1230 manual but is not very clear about some functions. I also sent email to Mr Charles ( I suppose Is the guy in the video) but isn't easy have an answer from him.

[Dacian Todea]

50mm2 cable (I'm surprised the connectors can even accept that) and with just 1m long there should be no voltage drop on the LiFePO4 side. What about the Lead Acid battery side ?

If all will work correctly then that charger should never get in to absorbtion or float mode (constant voltage) and should always be in Bulk (constant current) charge mode until the SBMS0 stops the charging.

Maybe check the connectors see if cables are well connected. You can measure voltage drop on the cables to see if you have some bad connections somewhere.

Also not sure what setting you made on the BB1230. You should set the absorption voltage to something high enough 14.4 or 14.5V so that it can never get there.

[Franco De Mei]

Hi Dacia,

Concerning BB1230 , refer to the manual , I think that I have undershoot why  at the power on BB1230 work fine, then to the next charging cycle  doesn't work . The  BB1230 as lIFePo4 charger  has 3 charging stages (See attachment), BULK 14.40 Volt, CONDITIONING 13.80 Volt and  FLOAT 13.80 Volt. When the BB start is on  BULK stage and the Time length is enough  to charge the battery. To the next charging cycle  We are already on CONDITIONING or  FLOAT stage and the voltage applied to charge the battery is 13.80 Volt . If I Understood the SBMS0  advanced settings , the End of Charge  value is settled on to 3.92  for each cell , that means the  EOC  for n. 4 cell is 13.92 volt ,  The BB1230  on   CONDITIONING or  FLOAT stage provide only 13.80 volt , 0,12 volt less then EOC.  If my argumentation is correct I have only 2 way to solve this ensue : Or I change settings to the SBMS end of charge  from 3.92 volt to 3.45 volt, or I configure BB1230 to CUSTOM  with all 3 stage  to 14.4 volt. I appreciate your suggestion. Thankyou.

[Dacian Todea]

Franco,

Not sure where you got that 3.92V from as there is no such default setting for SBMS0

The default max charge voltage is 3.55V for LiFePO4 thus with 4 cells battery will never get to 14.4V usually before 14V tha charging will stop thus charger will never get to the absorption voltage of 14.4V unless charger voltage measurement is quite a bit off.  You can also set the charger as 7) Calcium then it will be even more sure it can never get to that point or use custom and set 15V or whatever is allowed.

[Franco De Mei]

Hi Dacian,

I don't know where is come out Value 3.92. I wanted write  3.48 Volt  as end of charge  value. See Attachment.  ( I wrote twice 3.92  and , believe me, I drink only water ).... That means the  SBMS0 stop the charge process  "EOC" when battery reach 13.92 volts. 

What I want to say is , if I understood , If the end of charge  is when battery reach 13.92 volt and  the charger  provide 13.80 volt,  the SBMS0 will never reach  100% of SOC. Then the opportunity is ( 13.80 divided by 4  = 3.45)  change  setting to SBMS0  from 3.48 to 3.45 or configure  BB1230 as custom  with all 3 stage  (Bulk, CONDITIONING or  FLOAT) to the same value 14.0 -14.2 (previously  I wrote 14.4 because BB1230 in bulk stage provide 14.4 volt )

[Dacian Todea]

The SBMS0 will stop charging when highest cell gests to 3.55V the total battery voltage is irrelevant and it will be next to impossible to have all cells equal at 3.55V as one of the cells will always get to 3.55V first the others may be just around 3.4V

There is no reason for charger to only provide 13.8V as absorption voltage is set at 14.4V and it will not even be able to get to absorption as it will be in bulk charge mode until SBMS0 stops the charger. If the charger ever get to absorb phase it means that SBMS0 has no ON/OFF control and you are just overcharging the battery.

[Franco De Mei]

Hi agree with you but If do you see the previous attachment,  to the Option (9) LiFePo4 profile   Bulk/Abs. 14.40    Cond. 13.80  Float 13.80   and I think this is  why,  after second cycle ( after +/- 2 hours) of charge  sbms0 doesn't reach 100% SOC . 

Below  what I asked to Sterling power and the answer :

(My question)

I have some technical information’s to ask you. When Lithium battery is selected, the voltage output is constant voltage, or change depending of the charging curve ? (Bulk;Abssorption;Floating). Is It possible to set Voltage out to get same voyage 14.4 In bulk, absorption and float mode  for unlimited time ? (Until BMS 1 trip to 0 volt)

(Mr. Will  from Sterling Power answer) 

The lithium setting is not dependant on curve but will drop to a float level after 2-3 hours of being on 14.4v – we would assume your batteries are fully charged at this point – my advice would be to leave it on the pre-set lithium setting

 

Thanks

Will 

[Dacian Todea]

Will,

The charger can never get absorption 14.4V as battery will never get to that voltage and that means it can never get to Cond or float.

So something is just wrong in your setup. Have you tried to set EXT IO4 (or whatever EXT IOx you use to control the BB1230) to type 0 and see if charging stops ?

When you re enable charging the charger should again be on Bulk charging.  How do you disable charging ? do you use ignition signal ?

  

[Franco De Mei]

Maybe I don't explained very well  what's happen. , As I arrive on my boat, I switch on the insulating switch,  Activating all systems. Assuming that the SOC is around 98%.  At this point the battery start to be charged. Charging current is (+/-) 30 A. after a while the battery reach 100% SOC,  the SBMS0 CFET go OFF , EOC light on, 0 Volt light on. EXTIO open, BMS1 signal to BB1230 go to 0 stopping the charge, in the same time  BP100 open contact.Therefore the  charging process is stopped. Until now the system work fine.  After 2 hours ( More or less) the battery   SOC drop down  again around 98%  the CFET light on, EOC light off and charging sequence start again. EXTIO4 close, then BP 100 close contact and BMS 1 signal enable BB1230 to charging batteries.  but after 2 hours the BB1230  output is 13.80 Volt, not enough to charge battery.  I suppose .

[Dacian Todea]

Why do you also need the BP100 ? That may be the cause of the problem as the charge may start slightly sooner than BP100 is enabled and that means charger being open circuit on the output will see 14.4V or more and think that battery is at that high voltage level then consider that battery is fully charged and it should just condition or float the battery.

Simples solution not so change anything to the circuit is to set the charger with custom settings and set conditioning and float to 14.4V if that is allowed in the settings or as high as that can be set as charger voltage is irrelevant when SBMS0 stops the charging.

[Franco De Mei]

Hi Dacian, 

I red only now your answer, I went to my boat to make same tests, I used also BP100 as double  control,  I tried also tu bypass  the battery protector but result is the same, then I configure the charge with custom settings, on my test I used 14.2 volts for all 3 stage and it work fine but in this case I have to remove the BP100 because with  custom settings  I can't remove the reverse polarity ( Live output). Then I found solution. In any case I dont understand if this only my problem or some other peoples have same issue.

[Dacian Todea]

Will,

I do not think many use the SterlingPower chargers as they are fairly expensive for what they are even compared to Victron and sure compared to Renogy models.

Not sure what happens but since battery never gets to 14.4V the charger should never be in any other charge stage except for the first one the bulk (constant current). Not sure what the reason is for the charger to be in any other charge stage.

The way a Lead Acid charger should work (and this one is no different as LiFePO4 setting on all this chargers is a gimmick) it to have those multiple stages minimum 3 of them bulk (constant current), absorption (constant voltage 14.4V) and then when current on absorption charging drops to around 10% of max current it should enter in float (also constant voltage but lower voltage).

So since a 4s LiFePO4 controlled by the SBMS0 with default settings the voltage will never get to 14.4V the charger should be always in bulk mode charging at max current 30A in your case and as soon as any cell gets to 3.55V meaning full battery the charging should just stop then when battery discharges charging should start again in bulk mode and again it will not be able to get to 14.4V so can not get to absorption mode.

Since you mentioned you use short and super thick cables it is not possible for the charger to see a higher voltage than battery not by enough to think it got to 14.4V and ven if that was to be the case it should be in absorption charging so it should still push as much current very close to 30A until current drops to around 3A (10%) before going in to next stage with reduced voltage and that could never happen. Unless the charger is fairly off and his internal measurement is much lower than real battery voltage so say battery is 13.7V but the charger reads it as 14.4V then it will think is already in absorption mode (constant voltage) so it will not allow battery to charge and reduc current maintaining what he thinks is 14.4V but in reality it is just 13.7V thus current will fairly soon fall to below 3A and then enter next stage conditioning or float.

[Franco De Mei]

Hi,

First I want to say thank you to everyone for support and suggestions. 

I solved all problems with battery to battery charger  Sterling Power BB1230/60 and Battery protect Victron BP100.

Was enough configure BB1230/60 with custom configuration, with al outputs settled to get out 14.2 volt. and configure Victron BP100 to work as "b" mode (Relay mode) . with C mode (Li-ion mode) was not working properly . Now when maximum charge is reached, SBMS cut off the charge current,  switching  off BB1230 and BP100.

Only doubt I Have is, why at the beginning, when the battery reached maximum charge the state of charge displayed was 100% and now only 99%, Battery monitor with decimal point show 99,9%.I don't think is a big deal, but just to know .

In attachment my final project  "as built"

[Franco De Mei]

In attachment  SBMS0 pictures and PV arrangement.

[Dacian Todea]

That is how I decided to round out the SOC so at 99.9% it will show 99% SOC. I prefer to be a bit pessimistic :)

 Looks good. The SBMS0 seems to be so small compared to all other devices installed on that panel.

[Franco De Mei]

Thank you Dacian for support.