DIY Portable Power Pack (aka solar generator) vs. Commercial off-the-shelf options

[Ps23Rick]

Ok.. So I think you're suggesting that I could, if I desire, add later a solar controller (and panel) that could eventually feed into the Sterling and let it massage the solar output voltage to meet the needs of the battery? Sounds reasonable.. I just need to understand whether I can fit all that into a case or not, etc.. Let me know if anyone has further thoughts..

 

[john61ct]

Yes, any DC power source claiming 12V.

Wind gennie, old garage charger off mains, alt of whatever vehicles are around, cheap solar kits.

Get the right gear that best meets your needs. What size box, how many of them is secondary.

 

[Ps23Rick]

If I want to be able to charge via AC I'm assuming I can buy just about any 12V power supply off Amazon or elsewhere that puts out 20-30 amps and feed that directly into the sterling? I'm going to assume the answer is yes.. Now I just need to figure out a wiring diagram for this beastie along with the other little bits I need. Thanks much!!

 

[john61ct]

If I want to be able to charge via AC I'm assuming I can buy just about any 12V power supply off Amazon or elsewhere that puts out 20-30 amps and feed that directly into the sterling? I'm going to assume the answer is yes.. Now I just need to figure out a wiring diagram for this beastie along with the other little bits I need. Thanks much!!

Yes in fact much safer with cheaper PS units since the Sterling lets you derate amps rather than relying on the PS's overcurrent protection.

But better to buy quality, e.g. Meanwell or Samlex.

 

[john61ct]

If Sterling has ability to boost voltage, it should work.
Something to note, alot of those 12V power supplies are regulated pretty close to 12V. +-10% seems common tolerance. So assuming its ’max could be 13.2V, thats a bit low for charging without boost voltage. Now I think of it, sort of remember Sterling says it wont even begin to work until its input voltage is 13.9V, dunno...
One nice thing, those powersupplies are fairly cheap to buy. Also, one can usually parallel them if higher current is wanted.

Most decent 12V PSs are 13.2V output.

Some are adjustable.

Sterling boosts or buck converts.

The BB series has a manual On function.

And any charge source can be paralleled.

Charles is planning on 180 & 240A versions.

 

[Ps23Rick]

Thanks guys! I found an adjustable power supply on Amazon (link here) that seems to go up to and slightly over 15VDC. That ought to work ok -- 30A also. Gonna order one today.. will see how things go here.

 

[john61ct]

Not nearly as good copy of Mean Well (MW, get it?)

Should be fine in clueful hands fronted by the Sterling, but start low current, and watch the temperature as you then raise the amps.

Do **not** put it directly on a large high-CAR bank or it may quickly fry.

Seen them used for equalizing **after** the bank is at endAmps 100% Full from the usual charge source, so current demanded is very low.

 

[Ps23Rick]

ha..ha.. btw .. when I buy the sterling, I gather its got a temp sensor option -- was thinking about adding that to the list of stuff to get. When you speak of watching the temps, I'm assuming the battery temps or are you referring to the supply/sterling temp(s)?

you've got me on that acronym.. "high-CAR".. In my case my battery bank will be just the one BattleBorn and nothing more... Sorry for being overly naive here.. I've got tons of computer experience and a decent amount of electronics experience but its been a while..

 

[john61ct]

I meant temp of that cheapie PS, if you see it's getting hot, be aware it may be on the verge of failing.

Sterling no worries, very robust self-protection.

Temp compensation sensor is a given afaic.

Nothing's got a higher Charge Acceptance Rate than LFP, famous for burning out a stock alt in minutes.

Sterling will help there too.

 

[Ps23Rick]

ahhh.. Thanks!

 

[bob949]

At some point it might be nice to add a solar charge capability -- which seems to me would negate the need for the Sterling as they're both tackling the same thing -- to charge the battery but from different sources. For now I'll focus on only 12V charging. I know that there are a bunch of small items I'll need that are not included here -- I just wanted to tackle the big fish in the room. Is this list more or less ok?

Did you check into either of these units?
Redarc bcdc1220 or Ctek D250sa, both dc-dc chargers with solar option built in.

 

[john61ct]

The Sterling DCDC B2B functionality is to front-end **any** 12VDC source giving adjustable charge profile to care for an expensive bank of a chemistry with precise needs. Nothing to do with solar controllers, certainly not an either-or choice.

For solar, my preference is to buy separate top-notch solar controllers sized for a particular setup's specific needs.

I like Victron's SmartSolar MPPT line, those bundled with DCDC units are not at all on par.

CTEK and Redarc make fine durable products, the DCDC component is lower cost than the bigger Sterling BBs but have very limited current capacity and they are not customizable on setpoints

for someone with very simple needs, keeping a battery topped up while the van's stored in the sun, of course fine

but neither bundled SC is user customizable on setpoints, do not allow high-voltage panels, have very limited current capacity and lack logging / reporting or integration with BMs.

 

[Ps23Rick]

Just checking back in.. I've got all of the major pieces to start putting this thing together when the drive hits me. I've drawn up a rough wiring diagram and was hoping to solicit thoughts on whether I've left anything out or miswired anything.

please note that I have no fuses shown in this diagram but there will be fuses in place as well as likely battery disconnects, etc. I also have no inverter connections or solar hookups at this point. The initial pointer here is to have the basic charging capability properly with monitoring. I will add to it at some point but the basics are the basics and are what is needed. Thanks in advance for any thoughts, criticisms, suggestions, etc..