[Closed] Camera batteries

I find it's quite rare I need more than a single battery's worth of charge in between being near a plug socket (it's rare I'll cane a full battery in a day, especially on an SLR), so I've always found it quite adequate to have one or two unbranded spares and only use them when I really need them. Never had any issues with that, and even if they don't all last quite as long as the branded ones (not that I've noticed a real difference) who cares if you only need them a few times a year, and then only for the period of time over and above your normal full charge.

7 Day shop batteries are a fraction of the cost of branded and I have had no problems with them at all. I know many other photographers who use them and also have had no problems. As for how many? I have a battery grip 2 installed and another 2 spare.

A few years back some llony on dpreview did a major test of the Olympus slr battery and assorted clones. OK, your camera may be a different brand but his conclusions are probably worthwhile reading.
His conclusion was that the Uniross clone's performance exceeded the oem. Here's his conclusion:

In summary, it is clear that price alone is NO guide to the capacity or safety level of a particular pack. One of the cheapest (7DayShop) packs had a perfectly good control board and quite acceptable build quality but was let down badly by puny no-name cells. A slightly more expensive pack (Sterling Tek) had no real protection at all, much poorer build quality and was grossly underperforming compared to the pack markings and the (different) advertised rating.
Fortunately, it is clear that good quality cells with adequate control and protection circuitry can be obtained far cheaper than the original and in some cases - the UNiROSS being a case in point - can equal and exceed it in all areas of build quality, warranty, capacity and protection.
Overall results as follows:
** Overall winner - UNiROSS VB104295 **
Second place - Energizer OM-1
Third place - Olympus BLM-1
Fourth Place - Hahnel HL-M1 (note 1, 2)
Best capacity - UNiROSS VB104295
Best value for money - 7DayShop PS-BLM1
AVOID at ALL costs category - Sterling Tek clone (note 2)
Note 1 - the Hahnel has recently been uprated to 1500mAh and I have no doubt would perform to it's specifications and this would likely give it third place over the Olympus.
Note 2 - operations like 7DayShop and Sterling Tek source packs from all over - the same 'own label' pack available in a few months time might have completely different internals.

Thanks for the advice guys

i've got 4 hahnel ones and 2 have stopped working within a couple of charges