which kind of rechargeable batteries can be use in BP 200 battery pack. the manual says with Ni-Cd it gives so and so exposures but doesn't say about which kind of batteries can be used. according to the manual, i cannot use lithium batteries for my EOS 300. is there any such restriction on use of rechargeable batteries. or all kinds of AA-size rechargeable batteries can be used in BP 200.

thanks

-- sajeev (chack74@yahoo.co.in), March 19, 2002

Answers

also what about batteries for speedlite 380EX. can i use lithium batteries for that and which rechargeable batteries (if restricted) can be used for that.

thanks

-- sajeev (chack74@yahoo.co.in), March 19, 2002.

Power and discharge curves of NiCads and NiMH AA batteries are nearly identical, so if NiCads are acceptable so are NiMH AA's. There is no restriction based on the amp/hour rating of the battery. The higher the rating the longer thay last between chargings.

I would get NiMH's with a good charger, as they have less problems with memory effect and are available in higher amp/hour ratings. But overcharging is still a concern.

NiMH's one big downfall is that they self discharge in two or three weeks if they are left alone. NiCads sef discharge too, but take longer to do it.

-- Jim Strutz (j.strutz@gci.net), March 19, 2002.

As far as the 380EX, I've used alkaline, Li, and NiMH in mine; no problems to report. I've used Li and NiMH in my 420EX; also no problems there.

The previous answer about how similar NiCd and NiMH are is correct - similar voltage, similar current. Any device that is happy to be powered by NiCd should also be happy with NiMH (though if you're thinking of using NiMH in devices that have built-in rechargers designed for NiCd, it's probably not a good idea since they need somewhat different rechargers - I have a Walkman-style CD player that can recharge NiCd batteries if you plug in a power cord).

Li is a bit different - they have the same voltage as alkaline, but can provide much, much higher current; they also provide higher voltage under load than do alkalines. Most devices that work with alkaline AA cells will work with Li AA cells, which is why packs of Li AAs often have a guarantee that the battery manufacturer will repair or replace any equipment damaged by them. But in the face of an equipment manufacturer's warning saying you can't use them, I'd err on the side of caution and avoid 'em.

-- Steve Dunn (steved@ussinc.com), March 21, 2002.

thanks a lot jim and steve. i will go for NiMH batteries.

-- sajeev (chack74@yahoo.co.in), March 23, 2002.