CR123 batteries in series for 12v

[D-Train]

I'm looking to power a 12v fishfinder. It needs to be light weight for portaging otherwise I'd just use the 7# gel cell battery I already have. Power draw is 100-650 mA depending on which of my two units I'll use.

Are there reasons besides cost that I shouldn't be considering 4x123 primaries in series to produce 12v?

Cost is not much of a factor because this setup is used once a year for 1 week. I do have a 123-based flashlight so I do have other power requirements for this format. Otherwise I'm considering 8xAA in series. I should probably stick with lithium versus alkaline to avoid the severe voltage drop associated with alkaline, and I'm not really wanting to invest in rechargables because I don't want to invest a lot initially in a setup that may evolve year to year.

 

[Floating Spots]

Welcome to CPF, D-Train.

You can stack (series) CR123A batteries.
However, they need to be the *SAME* capacity and charge level.
Use all new, same brand, high quality, US made batteries and discard them all at the first sign of low voltage.

If you look through the fire threads, you will see that CR123A vent violently when reverse charged.
If one battery is weak, it can be reversed by the others in the series string.
As such, you need to plan for possible fire, slim as that chance is.
(If you want to run the remaining life out of them, a single CR123A flashlight is safe to do so.)

At your max of 650 mA, you aren't going to get more than about 2 hours of use on 4 cells.
At your min, you would see about 15 hours.
(CR123As are about 1400 to 1500 mA.)
Series strings of cells only increase the voltage, not the current.

Hope that helps,
Jon

 

[eh4]

Edit: Sorry, I just reread and understand that you are not concerned with the cost of CR123 primaries because it won't be used often, but that you don't want to invest in rechargeable batteries...
I'm gonna leave the following up in case you or someone else decides to get an automobile emergency booster battery that they can take out in the field to power other 12V stuff whenever they want to...

Consider LiFePO4 batteries, safest chemistry, more energy than NiMH, light weight, high charge and discharge rates(depending on manufacturer), very long life, the same battery can replace both lead acid starting battery and lead acid deep cycle battery.

This might be too light weight for a booster battery but just as a for instance try searching

" Custom LFP 26650 Battery: 12.8V 3300 mAh (42.24Wh, 7A rate) with Male Tamiya Connector (3.96)y "

40+ Watt/hours of 12 Volts weighing 10-12 ounces is pretty cool. 🙂

This cold weather jump starting video is kind of neat too: http://www.youtube.com/watch?v=BVMR-_mYfu0

I have no actual experience with LiFePO4 yet until disposable income improves, just a big fan from reading up on the chemistry and the batteries.