Battery Clinic (Chapters I and II & Follow-up Q&A)

[WThesing]

The way to resolve the question on the sealed pack is as follows:

Determine the capacity of the pack. Example: 2000 Mah.

Determine the charger outputs. Example: Quick charge = 500 Mah. Divide 2000 by 500 = Charge time of 4 hours.

Slow charge = 200 Mah. 2000/200 = charge time of 10 hours.

Connect it to a timer set for 10 hours or 4 hours to prevent overcharge on FULLY DISCHARGED pack. You can make a simple discharge device by wiring 10 12V. 1 to 2 Amp automotive taillight bulbs in series and connect to pack. Just wait until the bulbs no longer light. Your pack sounds like it is Nimh cells. Remember that the slower charge will give you more capacity in the pack, where a quick charge will give you increased initial voltage.

[ToddB64]

Hi Bill !

The following questions regard rechargeable AA batteries used in solar powered devices such as driveway accent lights. Off hand, I am not aware of any solar powered battery chargers made for the singular purpose of charging batteries, just the more prevalent AC type that we plug into our home electrical outlets and that include a rectifier to change the AC to DC before going to the battery.

More specifically, I am thinking of solar powered accent lights, using AA, standard 1.2 DCV, 700 mAh batteries, or any other higher/lower mAh value batteries that might be used by different solar accent light manufacturer's, having designed their accent light for such.

Questions: Can I safely use a somewhat higher mAh battery than what the solar unit was designed for, as long as the battery length fits between the positive and negative contacts ? As a general rule, where would you put the mAh maximum limit on this, in terms of mAh percentage of increase over and above the original mAh's intended for the device ? I hope this is clear.

Thanks Bill, for the great information resource you have provided here and I look forward to your reply.

Best Regards,

Todd

PS: I looked through your Battery Clinics One and Two, as well as Follow UP and Questions thread, but did not notice anything on solar chargers.

[Paul M.]

I didn't read the whole thread, just your post, Todd. The lights are only going to draw the current they need. So a battery with a higher mAh rating will produce voltage for a longer period of time than a battery of a lower rating, given the same voltage ratings.

As an example, it is popular now to use Ni-MH batteries in digital cameras. The higher the mAh rating the longer they last before having to recharge them. The voltages are pretty close to regular alkaline batteries.

So short answer, yes, you can use higher (or even lower) mAh rated batteries.

[ToddB64]

Originally Posted by Paul M.

I didn't read the whole thread, just your post, Todd. The lights are only going to draw the current they need. So a battery with a higher mAh rating will produce voltage for a longer period of time than a battery of a lower rating, given the same voltage ratings.

As an example, it is popular now to use Ni-MH batteries in digital cameras. The higher the mAh rating the longer they last before having to recharge them. The voltages are pretty close to regular alkaline batteries.

So short answer, yes, you can use higher (or even lower) mAh rated batteries.

Thanks Paul ! If you don't mind, I have a couple more questions.

#1) Is there anything special about the rechargeable batteries used to power solar lights ? In other words, would it be OK to use the same rechargeable battery in a solar light or in a kids toy that requires the battery to be periodically recharged in a standard AC to DC battery charger ?

#2) Does the diameter and overall length, of standard and rechargeable AA size batteries, vary with the amp hour rating ? In other words, is it necessary due to construction, for the battery to be somewhat larger in length and/or diameter in order to deliver a higher mAh output ? Or is the slight size variation I've seen between two different brands of AA's due to reasons other than the mAh output ?

Todd

[Paul M.]

Hi Todd,
Sorry for the delayed response. I'm back in school and still working full time, so I have little time left to read the forums.

#1) The thing you most want to be concerned with is voltage. What voltage do the circuits need to operate and what voltage your batteries put out. The amp/Hr rating (or mili-amp/Hr rating) will determine how long the batteries will provide that voltage.

If the two devices use commercially available batteries, it makes no difference whether they are alkaline or some rechargeable type, as long as the voltage is correct and the needed rating is high enough for that device.

#2) Diameter and length are not factors in capacity and ratings, just manufacturer's construction of the batteries. There is a standard that they go by but the tolerances for the dimensions are somewhat loose, hence the variances between brands.

Hope this helps.

[ToddB64]

Originally Posted by Paul M.

Hi Todd,
Sorry for the delayed response. I'm back in school and still working full time, so I have little time left to read the forums.

#1) The thing you most want to be concerned with is voltage. What voltage do the circuits need to operate and what voltage your batteries put out. The amp/Hr rating (or mili-amp/Hr rating) will determine how long the batteries will provide that voltage.

If the two devices use commercially available batteries, it makes no difference whether they are alkaline or some rechargeable type, as long as the voltage is correct and the needed rating is high enough for that device.

#2) Diameter and length are not factors in capacity and ratings, just manufacturer's construction of the batteries. There is a standard that they go by but the tolerances for the dimensions are somewhat loose, hence the variances between brands.

Hope this helps.

Thanks Paul.....it does help !

Say, BTW, are you and Bill Thesing working together on this thread as far as answering members questions, or is it open to other members who feel qualified to make replies ? Just curious.

Todd

[WThesing]

I have had relatively little time to check in over the past couple of weeks due to getting things set for me to go away on vacation. I am not against anyone else chiming in with their knowledge. With the solar charging system, the capacity fed will vary with the intensity and volume of the power source. On a cloudy day, the amount of sunlight, and whether there is enough over a given time to sustain the maximum voltage output. It's like having a 20 gallon tank, and needing 5 gallons to drive at a given rate for 8 hours. You sometimes get a 10 gallon fill or maybe only a 5 gallon fill. On rainy days you may only get 2 gallons and then draw off of a reserve that was built up over previous time. LED's use about 100 times less current than bulbs, thus the long run time on minimal Mah storage.

See you guys in a couple of weeks. I leave tomorrow.

Bill

[GeorgiaJay]

Bill
Thanks for all of the great info on batteries and charging them.
I just got some reward points, from a local store, and I need some more AA batteries for my mdr, camera, and Xbox 360 controller.
The only rechargeable AA batteries, that this store has, are the Energizer 2450 mAH NiMH batteries.
I was wondering if these batteries will work well with each of the electronic devices that are listed above?
Thanks for your opinion!

[ToddB64]

Hi Everybody !

I see from his Profile that Bill hasn't been active on this website since 5-28-2009.

Is he active on any other websites that you know of ?

I sent him a PM 12-16-2009 with a battery question, but no reply.

Hope he is doing OK.

Thanks !

Todd

[LittleJohn]

http://www.amazon.com/PowerGenix-ZR-.../dp/B0029NZVZ0

These batteries are the best rechargeables I have ever used in a metal detector. From my Tesoro's to my White's v3i....these do a great job, last a couple days worth of hunting and have never let me down yet, going into their second season of use.

Hope to hear from anyone else who has used these batteries.

Happy Hunting

LittleJohn

[Midasmulligan]

Hope Bill's O.K. Just wanted to thank him for the post as well as his service in Viet Nam, Republic of.

[sonnydigs]

No text.

[GlassGuy808]

Awesome explanation! Thank you!

[1Graeman]

Ok, I just bought a BH Pioneer 505 and it says to use Alkaline batteries in it. 9v batteries are pretty expensive, so I went and bought some new 9.6v rechargeable NiMH batteries. Is it ok to use them in the MD?

[MadTownScoop]

For my AT-Pro, I use the Energizer Lithium Ultimate AA batteries. Ive gotten them to last for 18-22 hours of use at around 3 hours per trip. Duracell AA's lasted about 12 hours and regular Energizer about 11-13 hours max. I got a guy I get an awesome price from for those ELU AA's and that's all I'll run. I also carry 4 with me new in pack just in case I hit my limit while in the field. I also carry either my spare Pro Pointer or spare 9 volt. Hate having to take the walk back to the truck for batteries.

[1Graeman]

Well, my rechargeable batteries are from Batteries Plus - the Powerex brand true 9.6v 230mAh. I bought the charger and it has both home and auto capability. Very expensive for my first purchase, but hopefully worth it.