Seeking more power than what a 1.5 watt solar panel could provide, it’s time to step up to the 100 watt solar kit, Harbor Freight item #63585. The manual, posted online as a PDF, fails to describe a few useful details which we’ll cover here.
Every product picture showed the four panels lined up in a row. But in fact the four panels are capable of standing separately as each panel is in their own frame and has their own folding stand. Bolting them together is optional. If the panels are to be deployed and stowed frequently, leaving them separate might make sense as the panels are much easier to handle individually.
The package content lists wires but not their length. Each panel has a 3 meter long wire permanently attached. This wire terminates in a connector common to Harbor Freight solar products but its exact type specification is unknown. It is definitely not the MC4 connector common in rooftop solar installations.
(UPDATE: Thanks to a tip in the comments, we now know this is a connector commonly used in the automotive world and can be purchased from auto parts stores. For example it is commonly used to make electric connections to trailers. While this connector follows the pattern of SAE J928 and J1239, it is not explicitly covered by either specification.)
The four panels connect into a 4-to-1 module. The four wire side are half a meter long, and the unified side has a 3 meter long wire towards the controller. A final half-meter long adapter has the unknown HF solar automotive connector on one end and a barrel connector on the other. (~5.5mm OD, ~1.5mm ID, 12mm length) The barrel connector fits into a corresponding jack on the controller.
Adding it all up: Each of the panels can be up to 3.5 meters from the central 4-to-1 hub, and that hub can be up to 3.5 meters from the controller. The package includes a 1 meter cable to connect controller to battery.
The kit included two LED light bulbs, each of which have a 5 meter long wire. Curiously, the long wire ends in a standard light bulb socket. But instead of the 120V AC household voltage we would expect from such a socket, it carries the battery DC voltage. This is a decidedly nonstandard and confusing way to do things. (UPDATE: An earlier version of this paragraph incorrectly stated 120V AC conversion took place, a bad assumption based on the standard light bulb socket. Voltage meter told the truth and paragraph has been rewritten.)
The simple charge controller covers the basics, guarding against battery overcharging and over-discharging at adjustable voltage thresholds. The manual claims there is over-current protection as well, but there appears to be no way to adjust the current limit, either for charging or for discharging.
New Screwdriver 
Thanks for the review. I just bought one and I am trying to find out what the size is for the barrel connector on the lights. The other end of the connector is a standard J connector used in cars. I bought one at an auto parts store. Do you have those measurements for the barrel connector? My son bought a separate charge controller because he said the Harbor Freight was not flexible enough…..so no he needs a pig tail with the female DC connector.
LikeLike
As far as I can tell, all the sockets in the charge controller are the same. So the barrel connector for the lights have the same dimensions as the solar panel barrel connector dimensions listed in this post. (~5.5mm OD, ~1.5mm ID, 12mm length)
Thanks for the tip on the automotive connector, I’ll look into it and update accordingly.
LikeLike
Nice simple kits. Had such good results with the first one I purchased a second kit.
Does anyone know if 2 (or more) of these set-ups can be wired together in parallel using one common storage battery? It seems pretty simple, just hook them together at the battery, however I’m not sure if I’m missing something that may potentially be dangerous, like exploding the battery or???
Please advise,
Tat
LikeLike
I’m no expert but until one jumps in, I’m going to guess it depends on the storage battery and how much charging current (amperage) it can accept. Be sure your battery’s maximum charging rate allows the maximum current generated by all panels combined.
LikeLike
More of a question than a comment. But can the led bulb be inserted into a normal 120v light bulb socket? I just bought the 100w kit and was looking at the bulbs and socket. And the socket is a generic socket with 240v molded into the plastic. Which I know the charger is only putting out 12v. Buuuutttt, can the led bulb circuitry be ran off the 120v mains electricity?
LikeLike
Honestly, I’m have not yet dared to try.
LikeLike
I just pulled out the bulb and looked inside of the bulb itself and can clearly see it is not built to handle 120v. Clearly not enough components on the circuit board to convert the 120v down to 12v. Sadly a bit dangerous of a design for this product to use. Because someone somewhere will end up trying to put this bulb into a regular socket.
LikeLike
I put a 12v led bulb in a 120v ac socket and the leds burned out in about 2 seconds. So, the answer is “No”.
LikeLike
I cant find the wattage of those LED bulbs anywhere. I used an sealed 12v 12aph battery and it only stayed lit for about 40 minutes. The charge controller shuts off the pwr at 10,8 volts
LikeLike
When I hooked one bulb up to my bench power supply and dialed up the voltage to 12.8V (nominal lead-acid battery voltage) it reported power draw of 320 milliamps. This works out to roughly 4W, which should last a lot longer than 40 minutes on 12Ah battery.
LikeLike
IS the charge controller PWM or MPPT?
LikeLike
Definitely not MPPT as I monitor panel voltage and it fluctuates based on battery state and not tracking maximum power point.
LikeLike
My batteries keep boiling over. I think I’m done with this controller. I have tried several settings and nothing seems to work. I ran them down to 12.5V today and leaving them like that for now. Disconnected the panels from the controller.
LikeLike
The manual hints at some kind of maximum charging over-amperage protection, but I found nothing to control the amperage limit. So another possibility is there’s more incoming power than your battery can absorb. Excess power turns into heat and things quickly go downhill.
LikeLike
I have one yes it works great for 100 watts and also provides lighting all-day but had problems with the first controller and would like one that holds 400 watts with the pig tail .
Great product 👍
Consumer,
David Lottig
LikeLike
Does anyone know if the 4 to 1 connector is wired in series or parallel?
LikeLike
Parallel
LikeLike
My charge controller quit working (out of warranty)
Harbor Freight wants $76 to replace it. I think I can cut and strip the wires an d just buy a $20 charge controller on Amazon. Or, I could adapt the connector to bare wires. Has anyone had success with this?
LikeLike
My batteries quit before my controller did. Or more precisely, their capacity severely degraded after a few years years of daily charging/discharging. Rather than buying replacement lead-acid batteries, I’ve decided to leave them behind along with the Harbor Freight controller. I’m exploring lithium-ion battery solar power storage instead. Right now I’m using one of these and it’s been working well so far, among its many features is a built-in MPPT charge controller to get more power out of the panels. https://www.costco.com/massimo-500w-12v-portable-lithium-battery-power-station.product.100691481.html
LikeLike