NiMH vs alkaline

[Navysalad]

Ok, I'm a Groundspeak newbie, so hopefully this hasn't been covered in a FAQ (I looked and didn't see it).

 

Simple question: Anyone know which lasts longer in a GPS (a Vista HCx, used on a kayaking trip for maybe 4 hours per day) -- alkalines or NiMH (the ones I just bought are rated at 2700 mAh, although they're made in China, so I'm not sure if that's reliable)? For this purpose, the cost is irrelevant.

 

NS

[+Ratsneve]

Ok, I'm a Groundspeak newbie, so hopefully this hasn't been covered in a FAQ (I looked and didn't see it).

 

Simple question: Anyone know which lasts longer in a GPS (a Vista HCx, used on a kayaking trip for maybe 4 hours per day) -- alkalines or NiMH (the ones I just bought are rated at 2700 mAh, although they're made in China, so I'm not sure if that's reliable)? For this purpose, the cost is irrelevant.

 

NS

Unfortunately alkaline battery manufacturers don't give you a mAh clue how long they will last. I don't think they are rechargeable either. Given time before your trip I would try a set of each. If you can leave backlighting and other functions you know you will be using turned on during the whole test it should give you a worse case time.

[+storm180]

My 60CSx on 2700Mah Powerex batteries run for 18 hours. Same batteries in my colorado 12-14 hours.

 

Alkalines don't last very long in any of my devices. I had a set of energizers which lasted only 4 hours.

Edited July 12, 2008 by storm180

[jholly]

Ok, I'm a Groundspeak newbie, so hopefully this hasn't been covered in a FAQ (I looked and didn't see it).

 

Simple question: Anyone know which lasts longer in a GPS (a Vista HCx, used on a kayaking trip for maybe 4 hours per day) -- alkalines or NiMH (the ones I just bought are rated at 2700 mAh, although they're made in China, so I'm not sure if that's reliable)? For this purpose, the cost is irrelevant.

 

NS

 

I have a GPSMAP 76CSx. I have the backlight on, compass on, and WASS enabled. From what I understand this is the max load. I have 2650 mAH batteries and they are still going strong after being on all day (6-8 hrs). Get a second set and your good for about a week. The second or third charge your ahead of the game money wise over alkaline. As far as losing charge while setting, I wouldn't worry much about that over a week or so.

 

Jim

[+twolpert]

If you do use NiMH rechargeables, be sure to condition each pair before your trip. If you have a conditioning charger, follow the instructions. If not, be sure to fully discharge and recharge the batteries 5 or 6 times before taking your trip. It takes conditioning before NiMH batteries will deliver their full, rated capacity.

[+Runaround]

Unfortunately alkaline battery manufacturers don't give you a mAh clue how long they will last. I don't think they are rechargeable either.

 

DISCLAIMER: I work for Energizer.

 

The Wikipedia article on alkaline batteries does a nice job in explaining why it is hard to give a stated capacity. It has to do with the chemistry of alkaline cells compared to NiMH.

 

Unlike NiMH rechargeable batteries, alkaline batteries are normally not sold with a nominal capacity. Alkalines have a high internal resistance, and a high thermal coefficient of resistivity — the faster an alkaline battery is drained, the higher percentage of the load it dissipates as heat. Therefore, the capacity of an alkaline battery is strongly dependent on the load, even at moderate loads. An AA-sized alkaline battery might have an effective capacity of 3000 mAh at low power, but at a load of 1000 mA, which is common for digital cameras, the capacity could be as little as 700 mAh.

 

Reads like it may have been written by a battery company engineer. Hmmmm.... It's also why there are different types of batteries on the market. None of the manufacturers are trying to confuse the customer but it come across that way. The key is to match the right battery to the application and device.

 

Personally, I use NiMH in my GPS. I can get all the free batteries I can use at the office but I like that I'm not always throwing something away.

 

One last thought. There are alkaline battery "chargers" on the market but I can't recommend against them strongly enough. The websites that sell them usually claim that the battery manufacturers use the threat of leakage (chemical burns), fire, or explosion to scare consumers away from these chargers in order to protect our market share. The truth is that we recommend against these chargers due to the unacceptably high risk of leakage, fire, and explosion. These are very real risks as alkaline cells were not designed to be recharged. I've seen the results first hand and it is scary. Before I'd let any of my loved ones use one of these "alkaline chargers", I'd rather go to Wally World and buy a pack of Duracells.

[Navysalad]

Thanks to everyone for their comments, much appreciated.

 

NS

[+stepshep]

Slightly OT; but where do Lithiums fall onto the scale of charge held?

[+Runaround]

Like alkaline, the performance of a lithium battery is very much application dependent but for different reasons due the difference in the chemistry. If you have a device with a high power consumption curve, lithium will outperform anything else, particularly in applications where alkaline performs poorly. Put some lithium cells in a low drain application like that wall clock hanging in your kitchen and they'll perform like most other batteries.

[+Tui Chub]

Here's a rundown test I did on a Vista HCX with Alkalines, NiMH and Lithium batteries. Scroll down to the second post.

 

http://forums.Groundspeak.com/GC/index.php...p;#entry3061300