Repair of Solar Rechargeable LED Yard Light

[xrunner]

Got a couple of these solar rechargeable LED lights two years ago. They come with a small IR remote control so you can control them from the ground. But this one wasn't holding a good charge and was very weak in the morning. I was guessing the battery was going bad, but they aren't designed to be repaired or disassembled. I know - shocking.

It appeared the only way in was to pry off the solar cell panel. I carefully worked the edges with a variety of tools until it came off. It was sealed against the weather with black sealant.

The battery inside was labeled CL-32650, 4 Ah. I assume it's a Li-ion cell. I haven't been able to remove it yet due to the glue they applied to the bottom of the battery. It's in the garage with some force being applied so hopefully the glue will give way eventually. may have to apply heat.

I don't come up with a hit for "CL-32650" battery. I assume any Li-ion battery 4000 mAh or better is OK? Please advise if you wish.

I tore the white underlayment getting it apart. Is that white plastic very important to the operation? I would like to get rid of it and then be able to seal the edges of the glass again to the plastic housing in a clean manner. Or I could just trim the edges of the white plastic around the outside.

You know it's a shame they make these things to be thrown away when the battery could have been made to be replaceable. 

[fzabkar]

Search for 32650.

"32650" appears to refer to the dimensions -- 32mm dia x 65mm length

[PeteH]

This looks like a LiFePO4 cell (lithium iron phosphate) due to 3.2V being on the label.

Standard/more common Li-Ion cells can't be used.

[xrunner]

Search for 32650.

This looks like a LiFePO4 cell (lithium iron phosphate) due to 3.2V being on the label.

Standard/more common Li-Ion cells can't be used.

Aha great advice now I'm finding them. 

[xrunner]

Found some 32650 batteries on Ebay that are 3.2V, 5500 mAh which would be an upgrade to the original battery. It doesn't look like the battery protection circuit comes with these batteries. I can salvage the one that was on the original battery which has the 8205A battery protection device.

[xrunner]

I scraped out all the black goop they used to seal the solar panel. Not sure what it is, doesn't seem like silicone. It "sortof" dissolves in alcohol. I wanted it all out of the channel around the outside of the plastic case. Think I'll redo some of the solder joints inside, not the best quality. 

Also battery ordered.

[blauerscharik]

You know it's a shame they make these things to be thrown away when the battery could have been made to be replaceable. 

My bathroom light went dark the other day. I could get inside by turning the front anticlockwise to the base. And then there were screws that held the LED strip and Powersupply in place. At first I thought, pretty nice of them to make it repairable right. Catch was though, they put epoxy into those screws  so I had to tediously remove them with needle nose pliers. And it was just one LED that went bad. They were all in series.

Too bad modern electronics are like that. But then everybody is talking about green green green.

[p.larner]

using fake/junk batterys in solar led lights seems to be the norm,seem to last 6 months at most,mass produced chinese rubbish!.

[xrunner]

using fake/junk batterys in solar led lights seems to be the norm,seem to last 6 months at most,mass produced chinese rubbish!.

Indeed, it's a shame they do this. Most people will just toss this thing in the trash and buy some other brand, lather, rinse, repeat.

I don't do much work with rechargeable batteries, so I'm brushing up on them. I bought two new LiFePO4 3.2V batteries. They have solder tabs. They don't come with the battery protection circuit, which I salvaged from the old battery (shown again below).

It protects the battery from overcharging and over discharging. The PCB has two SMDs - a 2112 battery protection IC, an 8205A dual MOSFET package, two resistors and a capacitor (like the attached schematic although the two resistos are different values). The 2112 senses the battery voltage and controls battery charging and discharging by use of the MOSFETs. I will re-attach it to the battery. If this repair works out OK I will go ahead and do my other identical LED light

[SeanB]

Did the same, though the front glass was the easier thing to remove, destructively. Replaced the two 32650 cells (recycled EV batteries I would assume) with salvaged 18650 laptop cells, and then used a DW01 board as protection for them. 10 cells in, all probably around 1.5Ah, a lot better than the mystery cells it came with, which powered it for around 5 hours, even when new. Now runs all night long, even in winter, and in summer should do better. Yes could have kept the old lithium iron phosphate controller, but as it had been drowned in electrolyte it was suspect. New glass cut to size, and stuck in with silicone sealer, and away it went back up on the wall.

[xrunner]

While waiting for the batteries I did a few things. These lights are outside in the clear to take weather all year, including the searing heat of the summer sun here. I painted the outside of the black plastic flat white.

Underneath, where the battery sits, are little vents ... well they're supposed to be vents unless you spread black adhesive goop all over them on the inside. Then your vents are rendered useless.

 

I cleaned the goop out and made sure the vents, well, vented. 

[xrunner]

Received two new LiFePO4 batteries today with a 5500 mAh rating as opposed to the 4000 mAh rating of the original battery. Old battery on top in pic.

However, upon extensive testing this afternoon with the original battery protection board, it was determined that the board is defective. It neither allowed charge nor discharge of the battery, which had a nominal charge of 3.2 V, and would power the LED array with no problems without the battery protection board wired in.

This may have been the actual problem with the light. I believe the 8205A MOSFET package on the board is damaged. Therefore, I ordered some new boards from Amazon this evening. They are not exactly the same board but have the same components and are for 3.2 V LiFePO4 batteries. Stay tuned ...

[p.larner]

just be aware a lot of faulty bms boards are kicking about,had a couple destroy a few cell groups in my prc-320 homebrew 7s radio battery,check first,had 2 run 3 cell groups to 0v with a non working lvc.

[xrunner]

That's why I'm testing the system on the bench, before sealing it all up again, before just assuming my initial diagnosis was correct.

And if the new BMS board works on the bench, I'm going to lay it all outside, connected, on a table before sealing it up to make sure it charges and discharges in full sun. This wouldn't be such a big deal if the case had been designed to be maintainable ... but it wasn't. The "average" consumer out there would have no idea what to to with this light if if failed, it would just go into the trash. How many have been sold, how many are in the landfill? It's a shame all this junk gets thrown away without a second thought.

[xrunner]

Good news - the battery protection board was OK after all. It seems it needed to sense a certain voltage from the solar panel before it would again allow the battery voltage to pass.

So I've re-connected all the components and it's outside test-charging.