The Epson R-D1 uses a rechargeable lithium (Li) ion battery (Epson part no. EU-85). This battery is identical to that used in many other cameras (e.g., Fujifilm NP-80, Toshiba PDR-BT1, Ricoh DB-20, Kodak KLIC-3000), with one important difference: The capacity of the Epson EU-85 battery is 1500 mAh, whereas the standard capacity of the other cells is 1300 mAh; however, higher-capacity (> 1500 mAh) generic batteries can be found.
Li ion batteries can be damaged if fully discharged, and their life-span is dependent on temperature (typically 3–5 years of normal use at room temperature) and the number of full discharge/recharge cycles. The following steps will prolong their life:
- Li ion batteries have a typical life span of 500 full discharge/charge cycles. Since Li ion batteries do not need to be fully discharged before being recharged, their useful life can be extended by charging them early and often, if in constant use.
- Li ion batteries should never be discharged fully, as this not only stresses the battery and reduces its life but it will become deep discharged if stored in this state, and cannot then be recharged.
- Li ion batteries not in constant should be stored 40% charged in the fridge (not the freezer!), as high charge capacities and high temperatures shorten the life-span; for example, after storage for 1 year, at 0° C at 40% charge capacity, 2% of the total charge capacity is irreversibly lost, whereas at 25° C at 100% charge capacity, 20% of the total capacity is lost (BatteryUniversity.com).
- Li ion batteries should be bought only when needed, because the ageing process begins as soon as the battery is manufactured.
- Allow the battery to warm to the ambient temperature before use.
- Avoid condensation forming on the battery.
- Li ion batteries lose about 5% of their charge per month.
There’s no reason why a generic battery can’t be used, since the genuine Epson one is not a unique design. The drawback to generic batteries is that most are unbranded ones of substandard Chinese manufacture (eBay is flooded with them), which can cause the problems described below. So, if buying a generic replacement battery, ensure that it’s a reputable brand (it’ll still be Chinese made but will have been checked for quality).
Users have occasionally reported problems with images being recorded as black frames, or the shutter locking up or not firing when using cheap, generic batteries, requiring the camera to be turned off then back on and, sometimes, the shutter speed changed. Epson told one owner who had problems:
It’s really important to use the original Epson battery. We’ve already experienced similar shutter errors while using non-Epson batteries.
No explanation of the cause of this problem was given, but it is probably related to the lack of capacity or inability to generate adequate short, high-energy bursts of an old and/or substandard battery: if the shutter lock ups or refuses to fire with a part-discharged battery, the battery should be discarded as it is possible that the shutter could jam, requiring professional attention.
Also, a common complaint is that many generic batteries have a significantly lower capacity compared with the genuine Epson battery despite being labelled as having an equal or higher capacity.
A replacement battery should therefore be of a high standard of manufacture, made recently and never subjected to high temperatures. It should also have a 1500 mAh capacity or higher (some batteries are marked 1600/1650 mAh). Although batteries with different capacities do exist, most labelled as having different capacities are probably identical. Unfortunately, it is difficult or impossible to verify any of the aforementioned with vendors.
Lastly, something to not worry about. Some Li ion batteries (including the Epson EU-85) are marked as 3.7 V, others as 3.6 V; however, all Li ion batteries produce the same voltage. This variation in voltage should thus be ignored: it arises simply from differences between how manufacturers define the average voltage.
A reliable battery for those in the UK appears to be the Jessops own-brand NP-80 (part No. JESHLNP80). Note that the Jessops website lists this battery as 1300 mAh whereas the battery bought from Jessops shops is marked as 1500 mAh; ensure that you buy the latter; alternatively, 7dayshop sells 1500 mAh batteries.
In the US, the North American Battery Company sells 1650 mAh batteries that are widely available (e.g., from RitzCamera.com), but, although reliable, they appear to last no longer than the standard Epson batteries, so I am sceptical about the high capacity rating.
There are plenty of NP-80 batteries available on eBay, some very cheap, but their quality may be questionable.
If you need a replacement or additional charger, note that the genuine Epson one costs about £100 (US $200)!
There are several non-genuine battery chargers, many of which are poorly made and originate from China. One I personally like is sold as a ‘travel battery charger’ (Figure 1).
- It’s small and very light-weight, with a built-in two-pin collapsible plug (i.e., no annoying mains lead). (Depending on where you live, a travel adapter may be needed.) Some vendors will include this.
- It’s cheap: I got mine new from a Hong Kong-based eBay seller (iBestMart) for £8 (US $16), which included a travel adapter plug, car-accessory lead and postage.
- It seems to be well specified: it charges batteries from any level to full capacity, including trickle charging when full capacity is detected; it has a charge-level indicator light; it has a charging time of 2–6 hours; and it uses any power supply from 110–240 V AC.
It’s available outside of eBay; for example the ‘XstreaM Battery Charger’ from SterlingTek.com.
A better-built, but more expensive (£35 or US $70), alternative cord-free travel charger is the PowerStation Ultima from Hähnel. This charger is more versatile as its front is interchangeable, so you can use it to charge almost any Li ion battery.