20 replies to this topic

[Vic Harder]

Looked around the forum but couldn't quite find any insight. I have my camper off in the garage for the winter (first winter with new 2017 hawk). I recently looked at my Victron Control app and noticed a low voltage warning.  I plugged in the camper to shore power and 3 days later I still am getting the same warning. State of charge says 100% and voltage readout is at 11.71. Nothing has changed in the 3 days of being plugged in. Voltage won't go up and warning still on. Wondering if if I should lower my low voltage warning, currently at 11.9, which was what the factory setting was. 2 AGM 79AH batteries. Also curious with camper off and battery temps at around 39 degrees should I be expecting different results that I would see in the summer? Any insight on best way to maintain proper charge during the winter? I live in Tahoe so temps in the garage will be fairly low most of the winter. 

 

Thanks

Did you clear the alarm?

 

From the manual:

 

3.8 Alarm, buzzer and relay

On most of the BMV’s readings an alarm can be triggered when the value reaches a set threshold. When the alarm becomes active the buzzer starts to beep, the backlight flashes and the alarm icon is visible in the display along with the current value. The corresponding segment will also flash. AUX when a starter alarm occurs. MAIN,MID or TEMP for the corresponding alarm. (When in the setup menu and an alarm occurs, the value causing the alarm will not be visible.) An alarm is acknowledged when a button is pressed. However, the alarm icon is displayed as long as the alarm condition remains. [emphasis mine].

 

https://www.emarinei...nul-English.pdf

[pvstoy]

But a multi-meter on the batteries each reading 11.8. Pulled the kill switch and all of the sudden batteries reading 13.9 and getting the same readout from my app. Now my question is....am I good?and should I just leave plugged in ?  IMG_0245.JPG IMG_0246.JPG IMG_0247.JPG

 

 

When you pulled the kill switch it allowed the charger to make the path to the batteries with the charge.  Yes leave it plugged in for a few days and monitor the voltage and watch the amps drop.  Your screen shot shows 19.6 amps going into the battery.  Keep charging so it can get close to zero and voltage is at float around 13.2 to 13.6 volts.

 

You can plug it in every month for few days or more to keep it topped off.  Or when you see the voltage drops to around 12.5 volts.

 

Just remember to pull the kill switch.

 

One thing to look at is you have two batteries in parallel (same for two 6 volt batteries in serial) and when you push in the kill switch then the two batteries are seeing each other without a load or charge. IF one of the two batteries has a lower resting voltage than the other OR one battery is going bad... then they will fight with each other trying to equalize the voltage.  End result is the voltage will drop faster and require more frequent charging. 

 

If you have a smart charger then you can leave it plugged in all winter. 

 

The Casita trailer I sold had three batteries and was able to separate all 3 when not in use as they were bought in different years.

[ckent323]

Oakleyrossi,

 

Your battery settings have 158 AH capacity and you say you have two 79 AH batteries. 

 

Are they two 12 v,79 AH batteries in parallel?

 

Is the Victron Battery Voltage Monitor (BVM) shunt across both batteries?

 

 

 

It is my opinion that your low voltage alarm setting is too low and your high alarm setting is to high.

 

That can be sorted out later once the charging situation is figured out.

Edited by ckent323, 12 December 2018 - 02:26 AM.

[Oakleyrossi]

Vic - Thanks for the heads up.. Just cleared it

 

Pvstoy - Yes I have a smart charger so I will just keep it plugged in except when I need to utilize the cord for something else occasionally 

 

Ckent - Ues batterers are wired in parallel, not sure what you mean if the shunt is across both batteries. I have the negative cable from one of the batteries to one side of the shunt.

[ckent323]

Oakleyrossi,

 

You wrote:

 

But a multi-meter on the batteries each reading 11.8. Pulled the kill switch and all of the sudden batteries reading 13.9 and getting the same readout from my app. Now my question is....am I good?and should I just leave plugged in ? 

 

Is that a typo and you "put a multi-meter on the batteries" and they are at 11.8V?

 

If so they are at SOC of <30%.

 

Pulling the camper power switch out and instantly seeing 13.9 V suggests to me that the BVM is seeing (measuring) the charger voltage.  I am now wondering in the BVM shunt is connected correctly.  One of the smarter folks on the web may see something obvious in this information.

I suggest that with the power switch out (camper power on) let the batteries charge overnight and recheck with a volt meter tomorrow.  If they are not over 12.1 V then I recommend you pull them out and take then to a parts store and get them checked.

[Oakleyrossi]

Thanks Ckent323 yes, I put one on the batteries.  

Sounds like a plan. When I get some from work I will see what it looks like and then test the batteries with a volt meter. If it looks fishy I will go from there. 

[ckent323]

OakleyRossi,

 

Sorry I was thinking series connection (I have two 6 V batteries in series).

 

I think the correct set up for batteries in parallel is with the shunt between the load and the most negative terminal (the battery where the load neg would be connected - not the neg terminal of the battery where the positive side of the load is connected).

Edited by ckent323, 12 December 2018 - 03:08 AM.

[pvstoy]

Just did this three days ago. plugged in ac current to the camper to charge batteries.  I had the kill switch pushed in and the Iota wanted to run and breakers lit up.  The kill switch severs the line to the battery.  Pull out the kill switch and then the charge will go to the battery. just as you found out.  That is why you saw with the volt meter 11.9 volts to the battery.  Normal.    As I also did see and confirm on the Victron that no amps going to the battery and still at low volts.  Normal.  until you pull the kill switch. then the Victron showed what the batteries were getting.

 

As far as the shunt, it is best to wire the negative to the shunt to one post on one battery bank and attach the positive to the opposite battery's positive post.

[Oakleyrossi]

Update... Came home tonight, still reading 13.9 on my app. Pulled everything off the batteries and then retested with a meter and got the same reading. Think all is well.  I will keep shore power plugged in ofter and wait for the spring skiing camping trip for next use.

 

Pvstoy - just noticed CC on your location.  We are not far from each other as I live up at the lake. 

 

Thanks for all the insight guys. Once again this forum has proved to be so valuable 

[ckent323]

Great news!  

 

Now I suggest you adjust the high and low alarm settings.   

Set low alarm at or above the minimum SOC you want to get to. 

 

For a 12V AGM Lifeline battery 50% SOC is at 12.2 V and 25% SOC is at 11.9 V.   I do not let my AGM true Deep Cycle batteries discharge lower than 50%.

You did not say if your batteries are true deep cycle or starting or marine (dual purpose) type.  If not deep cycle I would tdo some research on your particular battery charge cycles vs depth of discharge and think hard about not letting the SOC ever get below 50% to 60% and typically no lower than 60% to 70%.

 

For an AGM I think setting the high alarm between 14.7 V and 16 V (depending on your particular battery) is worth considering.  It is my opinion that 19 V is too high.

Here is a charging voltage chart for Lifeline AGM Batteries - but I recommend that you get and refer to the equivalent chart for your particular batteries)

 

 

I occasionally get into 0 deg to -10 degree weather with the camper but most of the time it is used in temps above 0 so I set my high alarm to 15.1 V. 

 

I am curious what others set their high alarm to and why.

 

Craig