ARC AAA with NiMH 750ma cell

what runtime can i expect???? thanks guys, i figure someone here has tried this.

although i haven't tried it yet i assume it's pretty easy to calculate... an ordinary AAA-cell has an approximate capacity of 1150mAh (got that info from this thread). it will power the arc for about 5 hours at sun-mode brightness. so 750mAh nimh will give you 5/1150*750 = approx. 3... i guess that turns out to say 2 to 2.5 hours of sun mode, followed by a short period of moon mode brightness. the initial output of the arc will also be lower than with alkaline-cells due to the lower voltage and the semi-regulation.

if you have some high-capacity nimh AAAs at hand this would be an option but i would not recommend rechargeables for this light. AAAs can be found at decent prices nearly everywhere and since it's IMHO more of a backup the cost of running it is almost negligible.

chris

I was just wondering, i ordered some NiMH AA's for another light and decided to grab 2 AAA's and try them in the ARC, but if it is not as good as the alky's then i will just use them in my VCR remote.

well, you can give it a try and do a runtime test and compare the light-output with alkalines.

chris

I haven't tried this, but doesn't the fact that NiMh's are better at providing higher current make up for the lower voltage? (I'm clueless about the voltage-under-load of an alkaline AAA.)

one thing about using NiMh in a remote is that they self-discharge fairly rapidly. However if you just pop them in the charger now and then you won't have any problem.

bart - that's true for full-regulation (voltage and current)... to my knowledge the aaa is 'only' semi-regulated (voltage). but the more i think about nimhs the more i like the idea - the flat discharge curve is nice. although i fear, what wits' end has already pointed out - due to the fairly high self-discharge rate you'll end up with a depleted cell if the flashlight gets used ocassionally only.

chris

Thanks ChrisA ,
yeah, NiMh's are cool! ( I just recently started using them, because I had a huge amount of NiCad's, but they are the next best thing besides sliced bread .... )
btw, I use a GP Powerbank Smart charger,and so far I like it . Cells do get hot , but since there is temperature sensing, I'm not worried too much about it. The ability to charge really fast is a plus for me.

nimh's are way to go ! just yesterday i was doing a runtime test with a handheld-gps loaded with 4 1800mAh nimhs. the device kept on running perfectly for 10 hours - after that i quit and went to bed this was done right after charging the cells for the first time. i guess they will do much better, when they have been cycled a few times... just make sure you get yourself a decent charger!

chris

I will try when they arrive, dont worry about self discharge, the light eats 2-3 Energizer E2 AAA's every month, so as you can tell it gets lots of runtime. I also ordered a mh-c204f charger for them, which seems like it has all the features i need.

ChrisA what runtime did you get on the GPS with regular alky's?

I have a bunch of AAA NiMH's, so I started running them in my ARC. I use mine several times a night, as I wear it around my neck & don't normally turn on the lights when I go in another room. The 1st battery finally went to moon mode after 4 weeks. I can't say I notice an output difference from alkalines. If I do a side-by-side, I can, but for normal use, it puts out plenty of light. This is the 1st battery I've ever had in the light where you actually see it flip to moon mode. On alkalines, you just notice after awhile, it's dimmer. With the rechargeable, when it gets low, it comes on full bright for 2 or 3 seconds, then goes to about 1/2 output. Then if you turn it off & back on, it goes to bright & stays bright, as advertised by Peter. I 1st thought it was a bad connection, but it did the same thing consistantly, several times. When it goes to moon mode, the battery was at 1.13V, which shouldn't hurt the NiMH. TX
PS
My batteries are only 550mah.

rifter - the gps will run for about 20 hours on alkalines with frequent backlight-usage... i'm quite sure once the nimhs will reach their full capacity they will power the unit for 13-15 hours. that's pretty decent, since i carry spares and plan hikes only up to 8 hours max - that gives plenty of savety-runtime.

txwest - that's much better than i would have thought. maybe i should give it a try... thanks for the info.

chris