Rechargeable battery for 2B?

[mrbutt89]

Hi. I usually run the 2B off the mains via the adaptor, but there are times when I run it on battery power instead.

I'm wondering whether it might be more cost-effective for me to use a rechargeable 9v battery rather than keep buying new ones.

Is this recommended? If so, what specification should I be looking for in a rechargeable battery? (There are so many different power ratings available, and I don't want to get the wrong one.)

[chestinut]

I run mine on an external 12v 3A sealed lead acid battery from screwfix:
http://www.screwfix.com/p/sealed-lead-a ... 34mm/21478

I included a 1.5A fuse and plug it into the external power supply socket.

[mrbutt89]

Thanks, Paul, but I want one that fits into the battery compartment. Otherwise I might just as well hook up to the mains.

[LondonSubNigel]

I've never tried a rechargeable in my 2B, but don't many of them have a slightly lower max voltage than the equivalents? Also, if it is only occasional use, I wonder if a rechargable would end up always being in the wrong state, or poorly conditioned, through not being stored in the right state, or discharged/recharged often enough. Although memory effect isn't such an issue these days with most, life can be considerably shortened in other ways.

When I put a battery in my 2B, I've had very good results with a Lithium one, which has a different discharge curve, compared to alkaline.

[mrbutt89]

Thanks for that suggestion. I'll try a lithium one next time.

[electroscott]

I use an external 3S LiFePO4 battery (9.6V nominal). Capacity is 3 Ah and lasts practically forever. Not as convenient as built-in lithium 9V but very portable, as it's a flat pack. Much more portable than AC mains. Enjoy

[Chris]

Hi, I am currently using a LiPo battery pack with 11.1V. It fits in the battery compartment of the 2B without any modifications and lasts a very long time.
Especially I use cells with a size of 50x30x5 mm, so the total height is 15mm. I bought these here: http://www.pollin.de/shop/dt/NDcwOTI3OT ... 0_mAh.html

[admin]

If you considering using LiPo, the remember the issues with over charging, over discharging, dropping them and more http://www.rchelicopterfun.com/rc-lipo-batteries.html

Si

[mrbutt89]

Thanks for all the useful advice. It looks as though LiPo might deliver what I want, but there are obviously a certain amount of issues to bear in mind.

[Chris]

Of course there are some issues with LiPo batteries to consider.
My self-built pack does not have an integrated protection circuit, but it has a 4-pin balancer plug and I am using a balancer charger to charge it.

But there are some packs which already have protection PCBs, which protect the pack from over- and undercharging, short circuits and also act as balancer. These are of course a bit more expensive and you have to look for one which fits inside the battery compartment of the 2B.