a good solar charger for flash lights

sltoussaint

Newly Enlightened
Joined
Mar 26, 2016
Messages
2
I am looking for a good solar charger for 10,000 Mah D cells specifically, and I haven't found any. The best I found takes 59 hours to charge two. I will use a pair in about 3 or 4 days. It will take longer to charge them than it will to USE them, so the math tells me no matter how many batteries I have, or chargers, sooner or later I will be out of power.

Does anyone know what the maximum charge rate that can be given to a 10,000 Mah D cell. I have toyed with getting a solar 12 volt car battery charger and putting 8 of the D cells in series and charging them that way, but considered the fact that they may charge to quickly and end up in an explosion has caused some concern.

I would rather buy something already on the market, so if anyone has had good success with existing chargers on the market that would work well also.

Thanks for your help

Steve
 

Poppy

Flashaholic
Joined
Dec 20, 2012
Messages
8,353
Location
Northern New Jersey
Steve,
I can't make a specific recommendation, because I don't have any solar.

Have you looked at This discussion?

Doing the math... 10,000 mah @ 1.5 volts is 15 watts hours. For each D cell.

They should probably charge over a number of hours, let's say 4 hours, so if you got a 15 watts hour solar panel, and charged 4 cells at a time, then in 4 hours, all four will be charged. Considering that there will be some losses, and not always perfect conditions, then I imagine that six hours in the sun, should do all four cells.

How long does it take to charge your D cells when running on mains power? You should be able to duplicate that running on solar. You may need a larger solar setup than whatever it is that you were looking at.
 

mcnair55

Flashlight Enthusiast
Joined
Oct 27, 2009
Messages
4,448
Location
North Wales UK
Can you not build a charger from one of those educational electric kits that the likes of Radio Shack/Tandy sell.
 

Bob2650

Newly Enlightened
Joined
Aug 1, 2021
Messages
66
My solution is not cheap or efficient but it is universally adaptable. I use a 12 volt deep cycle lead acid battery and a small 120VAC inverter. Then plug in the usual battery chargers such as a Maha MH-C808M for the Centura 8,000 mAh flashlight batteries. Charges 8 at a time.

The primary use for the deep cycle battery is radio and and a couple LED lamps. It is kept on a float charger.

I used to use a home made gasoline engine powered 12 volt DC battery charger built with these parts:
But the Honda EU2200I and a vintage gas station heavy duty battery charger is somewhat more efficient and quieter. That old charger is totally manual so I don't try for a full charge with that monster, 90% is close enough and cuts the run time on the generator if there is no other reason to run the generator. So far, I have not used it except for tests as our utility company power has been constant lately. Whenever I need to run the generator for the AC or the heat one or more of the battery chargers will be plugged in. I have two Maha MH-C808M and several other Maha chargers and a modern computer controlled 12 volt battery charger which makes a bit better use of the generator run time.
I see solar charging systems and a big bank of batteries as an expensive toy that can not push AC or heater for usefull periods of time without extreme expense but no doubt I will convert some day. It is always very hot or very cold when the power goes out.
 

Bob2650

Newly Enlightened
Joined
Aug 1, 2021
Messages
66
The Maha MH-C808M is usually stupid expensive on ebay but if you set up a search great deals come around once in a while. I paid about $20 and $30 including shipping for mine. Those unfortunate sellers did not guess the shipping correctly and made almost nothing on those deals. If the display is not working completely, power supply missing or seller feedback is under 99% let someone else buy it! No such thing as a great deal on a piece of junk.
The Maha MH-C808M does not run on 12VDC but 18 and 20 volts so it can not be powered directly from typical solar systems.
 
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