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

Hillbilly Heaven

Hillbilly Heaven

Explorer
pdavitt said:
I agree about the hall effect sensor. I have one in my Fluke 376FC AC/DC clamp meter and it works great. However, trying to find one you can install in a system with meters that can read it is, another story.
Pat
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There are many available that are either 5vdc or 12vdc powered with a 2.5vdc + or - 2vdc output. Meaning that zero amps is 2.5vdc.

Verkstad said:
Be careful doing this. 12V from the car has considerable current available what may exceed ampacity of many solar controllers.
Click to expand...

That is why you use a breaker and wiring between the 12vdc source and the charge controller rated for the max of the charge controller.
 
1

1EPICFJ

Member
Lots of good inputs here, but some of this seems overkill. I wish someone would just develop a simple, user friendly LFP system with 100AH that I can charge via Solar, AC, or DC and came with an inverter that put out 1500w continuously. What are the suggestions to get these items into as smallest of form factor as possible?
 
J

john61ct

Adventurer
Fully user adjustable DCDC charger.

I like Sterling BB series.

If you don't care that much about longevity, straight off the alt

Both require fat, quality wiring, and meters showing volts and amp acceptance at the battery.
 
1

1EPICFJ

Member
john61ct said:
Fully user adjustable DCDC charger.

I like Sterling BB series.

If you don't care that much about longevity, straight off the alt

Both require fat, quality wiring, and meters showing volts and amp acceptance at the battery.
Click to expand...

This is where it starts to not make sense to go DIY. When you add up the cost of the components and the footprint they take up it's impossible to contain them in a compact, portable option. The commercial solutions are looking better as this thread goes on.
 
JJBiggs

JJBiggs

Supporting Sponsor | SEES
Been there and done that. I purchased an Arkpak not so long ago and cringed at the crappy build quality. After making an LiFePo4 system for my trailer, I decided to make a portable unit as well.

Here is the result.

JOdMBMK.jpg



23OT9F8.jpg



WL886Rq.jpg




The final unit came in at 14.90"L x 12.10"W x 9.60"D and weighing only 25lbs. The unit was made from a Seahorse case and was fitted with the same LFP battery. Took me a little while to find a small master switch, but it turned out great.

I had the top face panel CNC'd out of aluminum skinned LDPE and then created the graphics file to be laminated and cut to match. All-in-all, I am pretty happy with the results.

Notes about the LFP battery - it needs to be charged at a higher voltage (between 14.2v to 14.6v) than conventional lead acid batteries. As such, I incorporated the Genasun MPPT charge controller to aid in recharging the system. There are a couple bits that I added once I learned about how the LFP's work. This particular battery is from evil bay and includes an onboard BMS that maintains the charge/discharge and battery leveling.

So far to date - I have been very satisfied with the results. Stay tuned for more.

C
 
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1

1EPICFJ

Member
JJBiggs said:
Been there and done that. I purchased an Arkpak not so long ago and cringed at the crappy build quality. After making an LiFePo4 system for my trailer, I decided to make a portable unit as well.

Here is the result.

JOdMBMK.jpg



23OT9F8.jpg



WL886Rq.jpg




The final unit came in at 14.90"L x 12.10"W x 9.60"D and weighing only 25lbs. The unit was made from a Seahorse case and was fitted with the same LFP battery. Took me a little while to find a small master switch, but it turned out great.

I had the top face panel CNC'd out of aluminum skinned LDPE and then created the graphics file to be laminated and cut to match. All-in-all, I am pretty happy with the results.

Notes about the LFP battery - it needs to be charged at a higher voltage (between 14.2v to 14.4v) than conventional lead acid batteries. As such, I incorporated the Genasun MPPT charge controller to aid in recharging the system. There are a couple bits that I added once I learned about how the LFP's work. This particular battery is from evil bay and includes an onboard BMS that maintains the charge/discharge and battery leveling.

So far to date - I have been very satisfied with the results. Stay tuned for more.

C
Click to expand...

That is beautiful. Can you provide some additional specs, such as AH size of battery, component list, etc.? Thanks!
 
JJBiggs

JJBiggs

Supporting Sponsor | SEES
1EPICFJ said:
That is beautiful. Can you provide some additional specs, such as AH size of battery, component list, etc.? Thanks!
Click to expand...

Thank you. The battery is a 50Ah. So that basically equates to the same usable Ah's as a Group 31 100Ah SLA. Except, this one weights in at 18lbs vs the 60-65Lbs of the SLA. Before I post a parts list...let me test this. I am certain it should work accordingly, but I'd rather use it in the field and be sure.

C
 
J

john61ct

Adventurer
But many of the packaged units don't allow for any fast charging option at all, require either solar input or mains overnight.

And the actual batt inside is what AH capacity @12V? Being charged internally at what voltage?

Can't even replace it after it dies 80% faster than the LFP DIY setup, supposed to just toss it and buy a whole new one?

Not for me thanks.
 
JJBiggs

JJBiggs

Supporting Sponsor | SEES
The Seahorse boxes are more reasonable and just as sturdy. They are also used in this manner for other industries. There are resources out there that also manufacture faceplates for the bottom and tops. CAD files for those are available online.

IMHO, LiFePo4 (LFP) batteries are a brilliant solution for power. They are inherently stable and take a charge quite quickly. I have been using my trailer system for many trips. The last being a 4600 miler from Atlanta to Loma, CO and down the Kokopelli trail. The system performed perfectly.

Notes regarding charging LFP's: LFP batteries like to have a charge that is between 14.2v to 14.6v. The higher side is best. My 4Runner only averages about 13.4v to 13.8 at the most. To aid with charging I added a 10 amp 15v voltage booster. The 15v is then dumped into the Genasun charge controller which then regulates the voltage down to where the LFP prefers.

So far, this has been working quite effectively. Would love some feedback regarding this solution.

Trailer setup:

48wDRss.jpg
 
JJBiggs

JJBiggs

Supporting Sponsor | SEES
john61ct said:
No, above 14V will drastically shorten LFP lifespan.

Better to stop at 13.8V
Click to expand...

I thought the same thing when I originally got started down this path. After reading about LiFePo4 batteries ad naseum (multiple sources), the initial charge rate is higher, then drops to the float charge rate. It is a 2 stage process. The end charge is 3.65v per cell (@ 4 cells is 14.6v). This was the biggest reason for purchasing the Genasun GV-10 14.2v MPPT charge controller that is specifically setup for LiFePo4 batteries.

The specs on this controller:
https://genasun.com/all-products/so...gv-10-li-lithium-10a-solar-charge-controller/

My last charge controller was also specific for LiFePo4 batteries but was a PWM style.

PWM Controller:
https://www.bioennopower.com/produc...controller-for-lifepo4-batteries-sc-122420jud

Price was good, but quality was lacking, IMO. Once again...the target charge is 14.6v.

More reading if anyone is interested: https://www.powerstream.com/LLLF.htm

And an edit: I highly recommend a LiFePo4 battery that has an onboard BMS. The BMS will monitor and equalize the cells. In addition, it will cutoff the charge and discharge to maintain the cells integrity.
 
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