First Step

[ibuzzard]

I am ready to begin , as soon as the Battle Born 12 v battery arrives. The first step is to install wiring between my truck’s starting battery, using either an isolator or continuous duty solenoid. I had purchased this Keyline isolator:     https://www.amazon.com/gp/product/B00WTAFR84/ref=ppx_yo_dt_b_asin_title_o01_s00?ie=UTF8&psc=1

I am now second guessing this - should I install a continuous duty solenoid instead? I intend to fuse both before and after whichever devise I do use. I will use #4 wiring back to the house battery. Hopefully next year I can add a second battery.

Off the battery, I have a Blue Sea 12 circuit panel with ground bus, and will fuse between the battery and this panel. What size fuse and wire should I have between the battery and panel? I  would also like to use some kind of battery monitor. Recommendations? 

I have a 2000 watt Yamaha inverter generator ( would love to trade it for a smaller 1000 watt unit) that has both 12 and 120 volt outputs. Can I also charge the Battle Born battery directly from the 12 volt outlet of the generator?

In Feb, when we visit friends in Phoenix, will pick up supplies to add the solar panel , a 400 watt from Santan Solar, to the roof of the camper shell. I have decided to downsize, only installing one panel.This is the one I was planning to buy:
https://store.santansolar.com/product/trina-405w/

 Also, I planned on using this controller, any thoughts? Is 30 amps enough for the panel?
https://store.santansolar.com/product/epever-3210-30a-mppt-solar-charge-controller/

Later, I intend to add an inverter to have 120 volt power.

Thank you for any help.

 

[jonyjoe303]

Can I also charge the Battle Born battery directly from the 12 volt outlet of the generator? yes but the amps would extremely low, on the yamaha its about 8 amps. They sell AC to DC chargers for lifepo4 that will charge at up to 20 amps or even higher. The battleborn can handle high charge rates.

With the sun overhead or shining directly on the panel and the battery depleted a 405 watt panel will produce more then 30 amps, thats in the summer.  30 amp mppt would be borderline for 405 watt panel. On the 30a mppt epever specs it says max pv input 390 watt (12 volt).

I been using the makeskyblue 60a mppt (130 dollars) on my 220ah lifepo4 for the past 6 months, its been working good so far. I like it because it has a feature where you can calibrate the controller voltage to the actual battery voltage, this helps if you have voltage drop from controller to battery and works extremely well. This controller (50a and 60a models) also won't cause voltage surges if the lithium battery bms activates, I encountered voltage surges on other controllers and it destroys any 12 volt equipment/devices connected to the lithium battery.

 

[Freelander]

That BB Battery will take a 50 amp charge.

 

[ibuzzard]

Thank you for the replies. I guess I will go with either a 40 or 50 amp mppt controller.

Regarding the isolator vs continuous duty solenoid - that isolator I purchased was highly touted, and I bought it. But, after watching several videos, one of them being Bob’s , I am second-guessing it and considering going with the solenoid. What are your feelings on that?

Also, do you have any input on a battery monitor to add into the system? Thanks.

 

[Freelander]

You won't get 50 amps from your panels. You can aspect upto 15 to 20 amps normally, it you charge from your altenator you can aspect a 50 amp charge. With 400 watts a 30 amp MPPT controller will be fine.

I have 3 of the BB batteries and installed one of these,

https://www.amazon.com/gp/product/B07DY8S815/ref=ppx_yo_dt_b_asin_title_o02_s00?ie=UTF8&psc=1

to charge from the alternator, this will charge both ways, it will allow the alternator to charge the BB's and the solar to charge the Chassis battery.

I use one of these to monitor the BB's

https://www.amazon.com/Victron-Smar...omotive&sprefix=Victron,automotive,193&sr=1-4

 

[ibuzzard]

Thank you, Freelander. That looks great, but I am already in hot water with my wife for possibly spending more on the continuous duty solenoid if I decide to do it, about 60.00. She’d go off the rails spending 172.00!

Between the two, would you use that isolator, or a solenoid?

And that Victron monitor looks as if it would need to be mounted down near the battery? I am wanting to have a cabinet, mounting the battery monitor, some 12 volt outlets, and eventually 120 volt outlets through the face of the door. Inside, I will mount the 12 volt panel and I think an inverter/charger.

I wish I was able to do the entire system at one time, but it has to be done piecemeal, as funds and the wife’s permission are forthcoming!

 

[Freelander]

I had a solenoid already and I removed it. With 3 BB's to charge I was looking at up to 150 amp charge, I only have a 145 amp alternator. This would have burned my alt up.

With the BIM unit, it cycles on/off and charges for 15 minutes and off for 20 minutes to save the alt.

And it also will keep the chassis battery charged while on solar. Since you have just 1 BB the solenoid will work just fine.

 

[jonyjoe303]

The isolator should work good. The only problem I see is that the alternator has to put out at least 14.4 volts all the time to charge lifepo4 and hopefully there is not too much voltage drop from alternator to the lifepo4. The more the voltage drop the less amps the battery will get.

For battery monitor I recommend the tk15 coulombmeter, I use them on all my lithium batteries, very accurate and inexpensive. You can get a 50 amp model for 30 dollars, the 100a model is in the 40 to 50 range. I had some of these running 24/7 for over 3 years, very reliable.

50 amp tk15 coulombmeter

 

[ibuzzard]

Thank you, again, guys. My truck is a 66 Ford, with a small capacity alternator by todays standards, I am guessing no more than 60 amps. Does that seem problematic? I am hoping that will be o.k. for just the one BB, but I might have to upgrade the alternator if I add subsequent batteries?

 

[Freelander]

My plan is if the BB's are really low is to run the generator and let it charge the batteries, I replaced my convertor with one designed to charge Lithiums, my convertor has a max output of 50 amp. When I last checked it took about 2 hours to charge from 65% to full charge.

 

[ibuzzard]

I contacted BB to ask whether I could charge the battery from my generator. Their response was that if the DC output is about 14.6 or 14.7, it will be o.k. I will have to check actual output, but I had thought it was supposed to be 12 volts.

 

[Freelander]

BB's like to charge at 14.4, that's where my solar is set to. You can charge it at less, but they won't got a full charge. I figured my Alternator can charge to whatever it is set, and the solar can finish it off.

My convertor charges to 14.4 and then goes to float mode to finish it.

Also my BB's never drop below 13.2 volts.

 

[theBest]

60a Charge Controller - Capable of a maximum battery charge current of 60 amps
400 watt panel is most likely ten or so amps, which means the voltage is 40 volts
Solar Panel --> Charge Controller INPUT --> 40 volts x 10 amps
Charge Controller OUTPUT --> 14.6 volts x 27.39 amps --> Battery

Two panels will put you near the maximum rated capacity of a 60 amp Charge Controller.
If your planning on adding more panels later, more than two total, you would need to upgrade your Charge Controller to one capable of providing 100 amps to 150 amps to the batteries.

How do you know how many amps the battery can handle?
For the batteries, you need to know the C rate in order to know how much current/amps they can handle Continuously vs Maximum.
A 200Amp Hour battery with a maximum current rating 1C can handle 200 amps maximum for short periods of time.
Said battery may accept .5C continuously, 100 amps, without problems
Sometimes there is an additional preferred charge rate, this is usually based on the manufacturers internal testing to determine the batteries sweet spot of how the battery best performs when receiving a charge.
Preferred Charge Rate - .25 C or 50 Amps

 

[Freelander]

That 400 watt panel is not going to put out 400 watts of power, if that panel is laid flat on the roof you will get a 30% to 40% loss of wattage. Unless you mount the panels so that they can be tilted into the sun. You'er only going to get a good charge from about 10:00 am to around 3:00 pm.

So 300 watts is closer to real output of the panels, the MPPT controller will increase the amperage some, it turns the extra voltage into amperage.

If the panels are outputting say 5 amps, the MPPT controller may put 6.5 amps into the battery. So expect to max amperage of around 20 amps.

Another to look at is, the wiring it need to be able to handle the amperage the panels are producing, on a 400 watt system 10 AWG is normally big enough.

 

[Freelander]

Also I noticed the panel you looking at says Max power current: 10.0 A, that seems to be about a third of what that panel should be. Most 400 watt systems will have a max output of close to 30 amp.

 

[ibuzzard]

Can you make another panel recommendation from the other panels SanTan has on their site? We are driving to Phoenix to visit friends in Feb., (probably) and I want to pick up supplies from them as well, since they are so close. SanTan was the place recommended by Bob in one of his videos.

I will likely not go beyond one panel, and so wanted to have the highest wattage I can. Admittedly, I know nothing about judging the quality of the components. I do prefer to buy high quality stuff, not cheaply priced only, so as to buy it once, and will scrimp and save to buy better stuff.

 

[Freelander]

I don't know anything about SanTan panels, I use 100 watt Renergy panels.

But 400 watts at 14.4 DC = about 28 amps

300 watts at 14.4 DC = about 21 amps

200 watts at 14.4 DC = about 14 amps

I just don't see how they figure just 10 amps from 405 watt panels.

 

[Freelander]

Renergy sells a 200 watt suitcase panel that that putts out 10.5 amps


https://www.amazon.com/Renogy-200-W...refix=renergy+solar+panels+200,aps,190&sr=8-3

 

[highdesertranger]

"I just don't see how they figure just 10 amps from 405 watt panels."

it's probably a 40 volt panel. I think you are confusing the output of the panel with the output of the controller. the output of my 435 watt panels is almost 80 volts that's only 5.4 amps but the controller knocks the voltage down to 14.5 and the amps up to 30.

highdesertranger

 

[Freelander]

You could be right, Max power voltage (VMP): 40.5 V

My panels are 19 volt panels.