Battery hookup questions, also Victron controller and BMV 712 monitor questions - Ram Promaster Forum
User Tag List

Reply
 
Thread Tools
post #1 of 27 Old 04-24-2019, 12:30 PM Thread Starter
yourrealdad
Senior Member
 
Join Date: Dec 2017
Location: Glenwood Springs, CO
Posts: 137
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 37 Post(s)
Thanks: 10
Thanked 12 Times in 10 Posts
(Thread Starter)
Battery hookup questions, also Victron controller and BMV 712 monitor questions

Got the electrical hooked up last weekend and am super excited. Thank you to all that helped me out in my other thread.
Since that one has gotten long I figured I would start another solely around the battery and charging/monitoring it.

Many of you have said that you either have fried a battery or know people that have and have done a good job of scaring me.

I will start with these two questions, but have many more:
What are the proper steps I should take or what are the big mistakes that people make that ruins their batteries?

My system is:

2x100w 12v Renogy Solar Panels wired in Parallel for 12v
1x100ah Renogy LiFePo4 battery
Victron Smartsolar MPPT 100/30 controller
Victron BMV 712 monitor
Victron Smartsense BT temp monitor

Right now the panels are not hooked up to the controller because I didn't want to have an input incorrect and damage the battery. I also know you do not want the panels connected to the controller without the controller connected to the battery, but my controller is hooked up to the battery.

I have to go, but will respond later to the parameters I have put into the controller and 712 later when I get home.

Thank you so much!!!!!

Van de Camps: 2017 159" High Roof. Started as a basic b*&%$, but like Beyonce said we can Upgrade U
yourrealdad is offline  
Sponsored Links
Advertisement
 
post #2 of 27 Old 04-24-2019, 03:08 PM
RDinNHandAZ
Senior Member
 
RDinNHandAZ's Avatar
 
Join Date: Jul 2014
Location: Summer in Lakes Region of NH and Winter in the Sonoran Desert of AZ
Posts: 6,583
Mentioned: 15 Post(s)
Tagged: 1 Thread(s)
Quoted: 1489 Post(s)
Thanks: 1,356
Thanked 1,668 Times in 1,294 Posts
Garage
If you are that unsure why would you drop that kind of money on batteries and controllers? We have electrical engineers and real sparky folks on this forum but if you don’t fit in that category a basic 200 watts of solar and lead acid with a MPPT controller and a WFCO converter would have lowered your risk of money lost by learning what not to do. Perhaps your needs are something that lead acid wouldn’t have done?? You don’t have a lot of capacity either so your system might have been about $400 instead of GKW.
Oh well we will help you through it.

Overcharging, undercharging, charging while frozen, dropping the thing, defective controller, wrong charge profile, fully charging, complete discharging.
Best really.

2015 136" HT Diesel 1500 Sandstone Pearl Metallic
Campervan build see:https://www.promasterforum.com/forum...ad.php?t=37177
You can browse my build pictures at http://tinypic.com/RDsPictures
Conversion Costs see: https://www.promasterforum.com/forum...ad.php?t=85761
$500 solar and $700 complete Electrical: https://www.promasterforum.com/forum...ad.php?t=71562
If you must make a mistake, make a new one each time.
RDinNHandAZ is online now  
post #3 of 27 Old 04-24-2019, 04:54 PM Thread Starter
yourrealdad
Senior Member
 
Join Date: Dec 2017
Location: Glenwood Springs, CO
Posts: 137
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 37 Post(s)
Thanks: 10
Thanked 12 Times in 10 Posts
(Thread Starter)
RD,
Thank you for all of your help. Seriously, it has been great. I truly appreciate it. I kinda thought we were done with the whole I hate Lithium thing, but if we must...

I dropped that money on a controller because see attached image (literally post #2 of my electrical thread) and in the same above post in this thread that you ask me why I would spend money on a controller you tell me to get an MPPT controller so I am confused and what YOU want MY system to be. I also have a WFCO converter to make things easier...It is hooked up and working.

So onward.
-I am worried about over and under charging, so if you have anything for me that would be great (again I am not at home so I can't really see what my parameters are now.
-Temperature cut off is set to .5C
-Haven't dropped it (knock on wood) and hey it weighs a 1/3 less than a Lead Acid so that should help
-Defective controller is kinda out of my hands isn't it, hopefully my expensive brand name one works
-Charge profile: Again a tricky one for me. Right now I have it set to 14.4 volts because Renogy says 14.4 +/- .2. Victron's LiFePo4 general was set up to 14.2, but I figured going to 14.4 was more in spec. I cannot find Renogy's absorption rate, so it is set at 13.5 per Victron, Peukert is set to 1.05
-I am curious about setting up SOC and how to calibrate so the BMV 712 and battery are in sync, but haven't gotten there yet.
-Discharge is set for an alarm at 10%

What else can I look into and other thoughts.

Thanks again
Attached Images
File Type: png Screen Shot 2019-04-24 at 2.03.17 PM.png (70.5 KB, 20 views)

Van de Camps: 2017 159" High Roof. Started as a basic b*&%$, but like Beyonce said we can Upgrade U
yourrealdad is offline  
Sponsored Links
Advertisement
 
post #4 of 27 Old 04-24-2019, 11:46 PM
RDinNHandAZ
Senior Member
 
RDinNHandAZ's Avatar
 
Join Date: Jul 2014
Location: Summer in Lakes Region of NH and Winter in the Sonoran Desert of AZ
Posts: 6,583
Mentioned: 15 Post(s)
Tagged: 1 Thread(s)
Quoted: 1489 Post(s)
Thanks: 1,356
Thanked 1,668 Times in 1,294 Posts
Garage
Hey I DO NOT hate Lithium. I’d do it in a minute if it were needed in my conversion. It does require a new set of knowledge parameters and I was serious to ask my question. I just had no negative intent. I want your system to be sufficient for your needs (which may be posted somewhere else, my bad for not going there) and be understood and maintained by you in a safe and efficient way. You have the batteries and the controller and are on the way. I listed the ways to kill batteries because I thought the question showed naivety and lacked specificity, no mean intent if you don’t agree. If you know the list you are getting there, answering with humor is good too. Thanks. Some of the experienced here can add much more than I who don’t have lithium yet. My take: there is an advantage to keeping them slightly less than fully charged and not letting them fully discharge. I know some makers list that you can use the entire 100 amp hours but my quick research said lifetime is sacrificed somewhat. I would not go to 10% but smarter folks than I may give different opinions. I’d do 20% alarm and when it activated I start charging. Leaving them for an extended time is a great advantage of current lithium but 95% SOC is probably a better place to start. I’d be nervous at .5C as the charge low temp, as it’s really close to freezing perhaps 1C or 1.5C gives a bit of safety. Going to, or calling the maker is your best plan and you are on to it. Perhaps the 14.2 is a better charge limit as you don’t float these batteries if I read correctly. "During the conventional lithium ion charging process, a conventional Li-ion Battery containing lithium iron phosphate (LiFePO4) needs two steps to be fully charged: step 1 uses constant current (CC) to reach about 60% State of Charge (SOC); step 2 takes place when charge voltage reaches 3.65V per cell, which is the upper limit of effective charging voltage. Turning from constant current (CC) to constant voltage (CV) means that the charge current is limited by what the battery will accept at that voltage, so the charging current tapers down asymptotically” Any modern charger with a LiFePO4 setting should do that and I’m sure yours will. Unfortunately the alternator won’t which is why you charge through a controller or use the alternator very carefully. And yes defective equipment is beyond your scope. If I made a mistake and ruined my batteries with a bad charger, controller or interconnection I’m smarter and the cost is $170. Your risk is higher and you have chosen a steeper learning curve. It will be fine.
Please report back as you have begun as we all (even the haters) need to get accustomed to this technology.

2015 136" HT Diesel 1500 Sandstone Pearl Metallic
Campervan build see:https://www.promasterforum.com/forum...ad.php?t=37177
You can browse my build pictures at http://tinypic.com/RDsPictures
Conversion Costs see: https://www.promasterforum.com/forum...ad.php?t=85761
$500 solar and $700 complete Electrical: https://www.promasterforum.com/forum...ad.php?t=71562
If you must make a mistake, make a new one each time.
RDinNHandAZ is online now  
post #5 of 27 Old 04-25-2019, 01:07 AM
ferall
Member
 
Join Date: Feb 2019
Posts: 34
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 12 Post(s)
Thanks: 0
Thanked 5 Times in 5 Posts
The bmv-712 will calibrate automatically once you achieve a full charge, given that you set it up properly. When you first connect it, it will read 100% no matter the state of charge.

I would highly recommend contacting Renogy and have them answer any questions you might have.
ferall is offline  
post #6 of 27 Old 04-25-2019, 07:23 AM
ThomD
Senior Member
 
ThomD's Avatar
 
Join Date: Sep 2017
Location: SF Bay Area
Posts: 567
Mentioned: 3 Post(s)
Tagged: 0 Thread(s)
Quoted: 139 Post(s)
Thanks: 104
Thanked 161 Times in 121 Posts
Check out this AM solar page. At the bottom are some suggestions for settings for various batteries and controllers.

https://amsolar.com/rv-solar/support

2017 159" Gas High top with dual sliders.
Build Thread
ThomD is offline  
post #7 of 27 Old 04-25-2019, 08:40 AM Thread Starter
yourrealdad
Senior Member
 
Join Date: Dec 2017
Location: Glenwood Springs, CO
Posts: 137
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 37 Post(s)
Thanks: 10
Thanked 12 Times in 10 Posts
(Thread Starter)
RD, ferall, and Thom thank you for the feedback. I went in and changed some settings today from further readings, but I think like you said I need to call Renogy.

Thom, that AM solar is a great reference point, they just don't have my battery on there and there seems to be some slight variances between the LFP batteries they have listed so I guess I really just need to call Renogy

Theme of the day: Call Renogy

I will post my parameters and see if they match up with what people think later.

Thank you again

Van de Camps: 2017 159" High Roof. Started as a basic b*&%$, but like Beyonce said we can Upgrade U
yourrealdad is offline  
post #8 of 27 Old 04-25-2019, 12:41 PM
nebulight
Senior Member
 
nebulight's Avatar
 
Join Date: Feb 2016
Posts: 482
Mentioned: 4 Post(s)
Tagged: 0 Thread(s)
Quoted: 122 Post(s)
Thanks: 42
Thanked 142 Times in 112 Posts
Garage
If you haven't already hooked up the Smartsense BT adapter, you do not need it since you have a 712 and a smart mppt. You can create the smart bluetooth network between the two if you have a temp sensor on the BMV. It is exactly the same readings and the temp sensor is right on the terminal.

As for charge settings, I'd suggest only charging to 14 or 14.2v. After you hit 14v, the voltage will jump fast and you get very little capacity above 14v. You may get 1ah more if you charge to 14.4v. I play it safe and keep the battery away from the top end of things.

And has ThomD state, AM Solar has a great chart:



I suggest somewhere in between:

BMV Settings:

Charged Voltage: 13.9V
Tail Current: 2%
Peukert Exponent: 1.05
Charge Efficiency Factor: 98%

MPPT:
Absorption Voltage: 14V
Absorption Time Limit: 1HR
Float Voltage: 13.5v

I don't think Absorption is really needed at all since lifepo4 has such low internal resistance. I also don't think float is really needed either since they don't need to be kept fully charged. But there is no setting to disable so keep it low.

I'd suggest a breaker on the positive between the MPPT and the battery if you don't already have one. You can also install an manual on/off switch between the positive panel wire and the mppt.

Current caretaker of the Backroader 159" wb
nebulight is offline  
The Following 2 Users Say Thank You to nebulight For This Useful Post:
akarmy (04-25-2019), yourrealdad (04-25-2019)
post #9 of 27 Old 04-25-2019, 01:40 PM Thread Starter
yourrealdad
Senior Member
 
Join Date: Dec 2017
Location: Glenwood Springs, CO
Posts: 137
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 37 Post(s)
Thanks: 10
Thanked 12 Times in 10 Posts
(Thread Starter)
Neb,

Thank you so much for your input. I was looking at that chart as well and I am just wondering how much of a difference those small differences make between the LFP batteries. Does 13.9v vs 14v for charged voltage make an overall big difference in the short or long run? My battery is not any of those types.

I have hooked up the smart sense because I thought you had to still purchase a wired temp sensor to work with the BMV 712?

Thank again

Van de Camps: 2017 159" High Roof. Started as a basic b*&%$, but like Beyonce said we can Upgrade U
yourrealdad is offline  
post #10 of 27 Old 04-25-2019, 01:54 PM Thread Starter
yourrealdad
Senior Member
 
Join Date: Dec 2017
Location: Glenwood Springs, CO
Posts: 137
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 37 Post(s)
Thanks: 10
Thanked 12 Times in 10 Posts
(Thread Starter)
Sorry for the post frantic lunch posting and forgot the image
Attached Images
File Type: jpg IMG_7477.jpg (249.0 KB, 21 views)

Van de Camps: 2017 159" High Roof. Started as a basic b*&%$, but like Beyonce said we can Upgrade U
yourrealdad is offline  
Reply

Thread Tools
Show Printable Version Show Printable Version
Email this Page Email this Page


Forum Jump

Posting Rules  
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off

 
For the best viewing experience please update your browser to Google Chrome