bulb is incadescent. Yes, the AA batteries are rechargeable, the solar panels recharge them.

What I'm confused about is for malibu lights, you run them on a 12v transformer and seemingly how many are run in series doesn't seem to matter (within reason) so why for my situation is the proper voltage to run completely dependent on the number of lights run in series vs. with the malibu lights it is not?

Most likes aren't run in series. It may look that way because the lights are lined up in a row, but if you look at the wiring, it is in parallel.

and all of those Malibu lights use 12v bulbs.

Just to add to Bill's note, in series, the voltage drops across each bulb must be added together to figure the total amount of voltage needed. When wired in parallel, the voltage that is delivered to each bulb is the same.

What is the voltage rating of the bulb, and how many watts is each bulb? If they're incandescent, it should be fairly straight-forward to re-wire each fixture to accept an external power source. The voltage and wattage of each bulb will determine what size transformer and wire is needed.

I have no idea what wattage the incadescent bulb is, the box doesn't mention it and the lights are discontinued.

I need to read more about wiring in series vs. parallel because I'm totally confused now since I thought 12v Malibu lights were wired in series, not parallel...

Most of the time the voltage and wattage are marked (or stamped) on the base of the bulb. At my age, a magnifying glass is often helpful. Of course, if you have a meter, you should be able to measure the voltage and the resistance of the bulb, which could be converted into the wattage.

Malibu lights are all wired in parallel, and as mentioned are typically 12V. BTW, it might be expensive to purchase a 3V exterior-grade transformer. Most outdoor/pool lights are 12V, so their transformers are more common and thus less expensive.

It simply is not practicle to wire unwired solar lights to be run by a 12V transformer. Period!

I'm not suggesting running these solar lights with a 12v transformer. Good point about exterior-grade vs. interior-grade transformers. I've seen inexpensive transformers online that let you select the voltage including 3 volt but they're really interior transformers.

Trying to wire a sting of lights with a 3V transformer means the wires will be HUGH... not very practical IMHO.

Solar lights use very low power lamps, so it may not be all that impractical to power them with a transformer. For a lamp to run 8 hours on a 1600mah battery (about the size of the battery I've seen in these solar units), the lamps can't draw more than 200ma (about half a watt in this application).

Your 15 lamps would thus draw about 7.5 watts. I don't know of any lighting transformer that would even break a sweat at that power level.

Note that two NiMH or NiCd cells in series will provide about 2.5 volts nominal, not 3 volts. Five lights in series should thus work just fine powered by a 12v transformer, IF it really produces 12 volts.

You'd make up three strings of 5 lights in series, then parallel the 3 strings across the transformer output. Try to keep the runs to the strings about the same length, though at 200ma only the smallest, longest wire will have much voltage drop to speak of.

One warning - you're probably getting into a fair bit of work here. You'd have to REALLY want to do this.

It sounds like a plan. What gauge wire should I use? Thanks!!

it might be easier to just buy some T10 wedge bulbs 1 watt and wedge adaptor and put these into the solar light assembly and use the 12 volt supply.

To start I got to say that I am not an electrician in anyways, but I do make things work by common sense, meaning maybe I’m wrong with my thinking at this time and my suggestion may work or may not work.

I’m about to do the same thing. I bought several sets of 4 light per solar panel that have low rating for their durability but the actual light fixture are just amazing looking, glass and metal and not plastic like all the low voltage garden set now being sold for a lot of money. Straight to the point. All it matters is really the fixtures. Why not buy a cheap set of 12volts garden lights, taking them apart completely saving the light sockets with the wiring and the bulbs then installing them to the old solar fixtures. Also keep in mind that the new set of 12volts lightings will include about 100feet of wiring and the new 12volts transformer to plug into your 110amps Electrical outlet. Good luck and if it works for you let me know. Thanks

I've busted apart some solar lights for another reason. I was building a set of backlit house numbers for my driveway and I wanted solar. Oddly enough, the things (cheap Lowe's floods) came apart nicely (held together with screws). It was a little tedious rewiring the things because the wires were really tiny inside (I'd have to guess around 28g or something).

But once you get them apart, yes, the wires to the bulb are indeed just 3V. The problem you have to check for is that LEDs need to be current limitted and you have to make sure you either haven't bypassed that in your butchery or that you provide a resistor of appropriate size to do the same thing.

Good advice, Ron. With traditional plastic package LEDs, a safe nominal current value is usually 20 milliamps. Many of the high brightness type will take more, but 20 ma is unlikely to damage any LED you find.

I don't have enough experience with SMD types to even guess, let alone COB.

The safest method is to measure the current they use in the original application, and either calculate an appropriate series resistance to maintain that current, or determine it by experimenting with different series resistance values while watching with your meter. Don't forget that if you change the device's heat sinking, you may not be able to maintain the same current.

I add, however, that the typical $3 dollar store solar garden light has no current regulation at all. It doesn't need any, because it uses a single 1.25 volt cell (usually nickel cadmium of about 300-400 mah) driving an LED with a nominal forward voltage of a bit over 3 volts. Hey, what did you think you were going to get for $3?

You can also use a regulator IC as a constant current LED source, but that's more effort than something like this is probably worth.

A sidebar. I've read that the reason you see so many cheap Chinese made products assembled with lots of screws - and even with hand-soldered circuits inside - is that labor is cheaper than machinery in China. Tesla electric vehicles are built largely by robots. Geely and BYD EVs from China are probably mostly, if not entirely, hand-made.

What about a buck converter.

It will cost more than that :)

Roshini, what's a buck converter? A converter that costs $1?

NW Retired

Hello, I see this is a really old article. Here is what I did. Removed the battery, circuit board and bulb. Purchased outdoor rated bi pin sockets and 1.5V and 2V LED bi pin bulbs. Assembled where the removed item resided. Wired all 20 Landscape Path Lights. Hooked them to a 100Watt Transformer. Our yard walkways are now well lighted. Do your home work on on sockets, bulbs and transformers. If this 79 year old Lady can do it. It must be a breeze

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