for all you lithium lovers...

codeman · Post by **codeman** » Tue Aug 30, 2005 11:44 am

I was bored, so I decided to do some research about my new lithium batteries. I found this site: http://www.sanyo.com/batteries/pdfs/lionT_E.pdf
It describes how they work...but most importantly, how to keep them working at peak levels for as long as possible. I know the most popular version is the 7.2-7.4v model, so just make sure you dont discharge it below 6v. If you do the internal protection will open the circuit and you'll need a special charger to reset it!

G-force · Post by **G-force** » Tue Aug 30, 2005 2:58 pm

Interesting... With that info, let's make a comparison.

Li-Ion
Charging times = 500
Shelf charge = Very long
Price = Kinda pricy. A 7.2V 2000 mah would cost ~$30
Shortest Charging time = About an hour (that's the fastest I have seen them.)

Ni-Cad
Charging times = 1000
Shelf charge = Not long. Maybe a week.
Price = Around $3 a cell. So a 7.2V 2000 Mah battery pack would be ~$12
Shortest Charging time = 15 minutes.

If I was wrong about some of this tell me and I will fix it. Personally I prefer Ni-Cad's.

*o* · Post by ***o*** » Tue Aug 30, 2005 3:25 pm

i prefer NIMH you dont have memory issues and they are higher capacity

codeman · Post by **codeman** » Tue Aug 30, 2005 6:46 pm

Li-Ion
Charging times = 500
Shelf charge = Very long
Price = Kinda pricy. A 7.2V 2000 mah would cost ~$30
Shortest Charging time = About an hour (that's the fastest I have seen them.)

Ni-Cad
Charging times = 1000
Shelf charge = Not long. Maybe a week.
Price = Around $3 a cell. So a 7.2V 2000 Mah battery pack would be ~$12
Shortest Charging time = 15 minutes.

good points, but i'm still an Li-Ion fan. I got two 4000mAh 7.2v batteries for a little less than $30. They're generally smaller overall than the equivalent voltage Ni-Cad, and much smaller for similar capacties. I'm putting both batteries in parallel for my NESp and anything else i make giving me 8Ah...enough to run anything for a good amount of time.

There's no memory effect, so you dont need to worry about discharging it to a certain point before recharghing. As for the charging time, if i can run my NESp for over 11 hours...i dont think i'd mind 2 hours of recharging.

Not to do any "battery bashing" but the Ni-Cad discharge curve stinks. When it reaches the end of it's cycle, it "drops off the cliff" so to speak. This makes it really hard to monitor the voltage to know when to switch to AC power. When the voltage reaches a certain point and your low battery indicator comes on you'll have only a few minutes to get off battery power or it will shut down. The Li-Ion and NiMH batteries have semi-linear discharge curves.

Anyway...sorry for the babbling