14.4v batteries: help needed

[Mickey Blue]

Hi all,

i just bought a MR11 kit from cutter with a 700ma buckpuck and 3 cree R2's and need a 14.4v battery to power it, but to spend $90 at batterspace with $70!!! delivery to australia is just plain silly.

can i connect 2 7.2v rc batteries in series to get a workable battery? what are some other options for me down here in australia?

also, could i make a pack myself? what about the pcb in commercial battery packs that protect it from over discharging or whatever..(could someone also explain this to me please)

thanks
michael

 

[Szemhazai]

Use Small Package International Forwarding Service from CPF. The shipping will cost you about 20$.

 

[HEY HEY ITS HENDO]

Hey Mickey Blue :welcome::wave:
2x RC battery packs is the quickest/easiest option....

http://cgi.ebay.com.au/Intellect-IB...ameZWDVWQQrdZ1QQcmdZViewItem#ebayphotohosting
.

 

[Zero_Enigma]

I have to ask, why the flying flock of birds does BatterySpace charge so high in S/H? I mean don't they make enough on the parts? Yah I'm at a bind because many of the parts I would like to un-uglify and make the light more convient to remove while traveling can only be found at BatterySpace unless DX smartens up for more business and can provide the same items I think I'm going to have to keep hunting for another store to buy stuff from. The waiting game is the uber suck one.

 

[Zero_Enigma]

Micky,

I share you pain mate. I'm lie 6000kms north of the 49th parallel and still I have to pay ~$40 for 2 x $9.99 bike mounts and a 1 x $4.99 switch.

BTW does anyone know if Batteryspace is online only or do they have some walk in store front? I think I might have to take a trip over to check California and while there stop by and pick everything up and save on the shipping. :duh2:

 

[znomit]

Has anyone tried batteryjunction.com?
Their prices look ok, and they have a good range, not sure on the shipping... they say USPS which has got to be better than UPS or fedex.

I was considering getting a couple of RC packs to make a high capacity battery for the MTB, I have a dozen AA energizers right now... but at around 150NZ$ for batteries another dyno is starting to look attractive.

 

[heatstroke]

another option is lipo packs from ebay. You can easily build a 4s pack for cheap. Just need a balance charger with appropriate plugs - which for lipos are cheap

 

[Jarl]

If you can stand using a 14.8V battery, then 4x protected 18650's would work, such as these
. Make sure to charge them independently though- lithiums don't take well to being charged in series.

 

[Dodge]

Where can you get a holder for four of them, though?

 

[A123Powered]

Why not build a pack from eneloops (12 of em in series), or 12 of any other nimh cells. You could do the same by merging two 6 cell nimh packs as you suggested. Another option is to buy a battery pack for a power tool and remove the cells (if you feel comfortable with doing that), though that would take some research to find a pack that uses quality cells (it could be quicker if you can get them locally).

You could also add a balance connector (simple) to keep the cells balanced when charging if you have a charger that supports it. There is a lot of info on some of the RC forums on building packs. Also Betteryspace.com forums have good information and the admins seem helpful with information. Here is one good article I found:

http://www.slkelectronics.com/battery/index.htm

Lipos are good for power and weight, but they can be dangerous if you don't take proper precautions. If you do go with Lion or Lipo, a multimeter is a good investment so you can check the voltage and make sure that each cell is charged to the same voltage before putting them in series. You can also add polyswitch fuses and/or thermostats to your pack for an extra margin of safety (http://www.batteryspace.com/index.asp?PageAction=VIEWCATS&Category=868)

I just found this link on the batteryspace site with some more info on safety
http://www.batteryspace.com/index.asp?PageAction=Custom&ID=32

For simplicity, I would stick with Nimh or a safe Lion technology for a bike light (which may take a few tumbles).

Doh, I just realized that I have been posting links to batteryspace and they are the ones with the high shipping for you, sorry about that. The cool thing about their site however is that if you can find a pack similar to what you need, they provide a lot of details on what parts they include in it and what charger to use.

 

[A123Powered]

Where can you get a holder for four of them, though?

The simplest holder would be a tube.