Li Po 9V battery for pedals etc

Started by utensil, June 24, 2013, 01:06:42 PM

Previous topic - Next topic

0 Members and 1 Guest are viewing this topic.

utensil

I find I use way to many 9v batteries  (pedals, wireless transmitters etc) and have been looking for a way to replace the alkaline with rechargeable ones. The Nimh batteries have pretty pathetic capacities, reputable brands put out a 9v with 125mah and max I've seen in 250mah.

I recently found these Lithium Polymer batteries which have a capacity GREATER than the alkaline 9v.
http://www.amazon.com/Hitech-Two-Lithium-Polymer-Batteries-Charger/dp/B0088R79RE/ref=pd_sim_sbs_e_2

Anyone use these niche LiPo batteries regularly (common with RC hobbyists). Any issues with safety in the home (Do I need to be in the room anytime it's charging). I've probably got so many Li-ion and Li-P batteries in my house in Camera's ,cordless phones,mobiles yet the handling instructions for RC and the above Li-Po batteries are very particular. In addition the common household battery brands (energizer, duracell, sanyo eneloop) don't seem to be making these making me feel they are a bit iffy.

Anyone have any experience or knowledge on the subject would be great.

GraemeJ

The downside is the nominal voltage - which is only 7.4v! This might be enough to power whatever you are using them in, but a small drop after a little use, could well mean it stops working altogether.

Also, they're not cheap.  For that sort of money you could buy a multi-output mains power unit... and never buy another battery.

utensil

The voltage seems to be ok since I often use 6 AAA (NIMH 900mah) batteries for some of the applications I'm thinking of but they are much more of a pain to charge than the one  720mah advertised. They are pricey but charger with 4 batteries is about as expensive as 8 AAA sanyo Eneloop's and a smart charger. This would be a better alternative for me since the 6AAA's are only a single set, with these I could have 4 ready to go.

I was more curious as to if the RC safety practices are generally required for all Li-Po Batteries (Charging in a Li-po bag without being unattended etc), because that would make these a bit impractical.



Machh_2

the chargers must charge the cell and balancing each one to have same voltage and current, each LIPO cell reach 4.2V with full charge, but without consumption.
The best usage this LIPO cells is between 4.2V to 3.7V, this bateries cells must never reach or pass than 3.5V or will condemn and nevermore works well...
probably within these batteries have 2 cell 3.7V (nominal voltage of each cell LIPO) than with maximum load on each (4.7V no consumption) would be 9.4V (7.4V nominal), but you do not have to balance the cells and always there will be differences between them and the performance will be impaired ...
What you can do is buy LIPO individual cells or batteries for electric model aircraft and put the plug 9V battery, these batteries for airplanes already come prepared to load-balanced, and has much more income and you will need a charger with balance system ... but as has the limitation maximum use of up to 3.7V, I think is not worth it ...
The image has a exemple...
[]´s

Elantric