OT: Yard Solar Lights (need replacement batts)

[oregonshooter]

Where can I find a good deal on 20 ni-cad AA batteries these days?

Best I found was $1.20ea after shipping for 700mah

Does capacity matter in this application?

Thanks for any help!

 

[jzmtl]

Duno about the first question, but I'd say even 700mah is way more than needed.

 

[DM51]

Moving this to the Batteries section...

 

[Belker]

My local Lowes had 600mah NiCd batteries in the solar lighting section. I think they were $5-6 for a 4 pack.

 

[warlord]

The local Harbor Freight has them and you can also try Battery Junction.

 

[phenwick]

The replacement batteries (Brinkman, Malibu, Harbor Bay in my case) available off the shelves locally are junk. They don't come close to labeled capacity and sometimes fail to charge out of the package, showing high internal resistance.

I suggest Sanyo Cadnica 700mAh, as a good replacement. I got mine from
Tower hobbies and;
Battery Store

These are workhorses and the 60+ I have charge up as labeled and continue to do so. I use these to replace the cells in the new lights I purchase as they are usually junk also.

 

[SilverFox]

Hello Jim,

I have had reasonably good resuts with these.

I think they came in closer to 1000 mAh, and there were a few that were a little strange, but overall they have worked out well.

Tom

 

[Black Rose]

Replacing the existing batteries with higher capacity batteries in theory could make them run longer, assuming the solar charger can top them up sufficiently, correct?

I wonder if using higher capacity batteries would make the lights any brighter? I expect not due to limits imposed by the electronics inside the lights.

 

[warlord]

If the solar panels could charge them to thier higher capacity yes but that's doubtful. They would not make the lights any brighter that's limited by the voltage, current, and LEDs.

Replacing the existing batteries with higher capacity batteries in theory could make them run longer, assuming the solar charger can top them up sufficiently, correct?

I wonder if using higher capacity batteries would make the lights any brighter? I expect not due to limits imposed by the electronics inside the lights.

 

[metlarules]

Most of those solar landscape lights charge at no more than 50ma due in part to limitations of the solar cell on them. They will not completely charge a modern aa to full capacity.

 

[matrixshaman]

I've seen some really cheap ones at Harbor Freight - especially if they are on sale. Probably fairly low mah rating but then I'm sure you don't need a lot to power those type of lights. I'm sure they were less than a dollar a piece but I don't recall exactly how much.

 

[oregonshooter]

Thanks for the posts guys, my email notification was not working. I'll try harbor freight first.

 

[Black Rose]

We picked up some solar powered LED dragonflies for our backyard over the weekend. The cells don't have any brand name on them at all.

One of the cells can barely run the dragonfly for 4 hours, the other one seems to be able run all night (I woke up at 4:30 this morning and one was still lit up nicely).

I have other solar LED lights in the same location sunshine-wise and they work fine, so I think I might have a cell with "issues". I put both batteries on a condition cycle on my MH-C800S to see if that helps. If not, I'll order some replacement cells.

 

[Black Rose]

Some good prices on NiCad AAs noted in this thread...international shipping charges pretty much negate the savings so I'm still looking.

Anyone familiar with TEnergy 1000 mAh NiCads?

 

[Lynx_Arc]

I often wonder if you never completely charge them would some nimh 1200s work about as well and be easier to find. nimh don't like to be overcharged on trickle but I doubt solar cells would charge them completely compared to 600-700mah nicads

 

[lctorana]

The problem with NiMH in solar lights is that every night, the cells are 100% exhausted to dead-flat.

NiCads can cope with that abuse to some extent, NiMHs cannot. They will die rather quickly.

 

[Lynx_Arc]

The problem with NiMH in solar lights is that every night, the cells are 100% exhausted to dead-flat.

NiCads can cope with that abuse to some extent, NiMHs cannot. They will die rather quickly.

I have never been impressed by the average solar yard light here... they dim too much after a few hours IMO.
too bad there isn't a drop out circuit to protect cells from overdraining.

 

[Turak]

As I said in another thread regarding the solar lights and replacement batteries....

Stick with the low capacity 600mAh - 1000 mAh NiCd's. There are a couple other threads that identify the pros of the Nicd over the NiMh for this particular application.

Also forget about anything higher than about 1000mAh, since the solar cell lights typically WILL NOT be able to fully charge them. Because of the size of the solar cells on most solar lights, they tend to only put out about 50mA of current in full, direct sunlight, less on an overcast day obviously. Do the math, this means that a 1000mAh battery would take at least 20 hours and in reality closer to 24-26 hours to obtain a 'Full' charge.

Just one of the reasons why the lower capacity cells work better in solar lighting applications. The lower capacities actually work better in the long run due to more complete charge/discharge cycles.

I go through all my solar lights (at least 14) each year and run the batteries through a Refresh/Analyze cycle (BC-900 or MH-C9000) to help make sure they get some 'full' charge/discharge cycles.

If you really want to get the most out of your solar lights and batteries, take one of your solar lights and measure the charging current during a reasonably sunny day (Note - indoor lights WILL NOT give you accurate rates, especially flourescent lighting) and size your batteries according to the current you measure times the average hours of daylight where you live.

It is also not too bad of an idea to measure the current 'drain' on the batteries when the light is actually on. This will give you a rough idea of how long the lights will actually run for.....providing they are getting a 'full' charge. Believe me, sizing the batteries properly really does make a difference when used with solar lights.

Harbor Freight (700mAh) NiCds seem to work as well as any of the cheapies that I have tried. Again, do the math, these end up taking a good 14-16 hours of sunlight for a 'full' charge which is just about perfect for where I live.

Looks like Harbor Freight is having a sale on June 6th, 7th, and 8th.

A 4 pack AA's (lot #47440) or AAA's for 1.99, normally 4.99.