[3] Since Sanyo introduced the Eneloop, many other brands of low-self-discharge batteries became available, described as "low self-discharge", "LSD" or "pre-charged".

Because they can replace a large number of alkaline batteries over their life cycle, Eneloops are marketed as being eco-friendly.

In exchange for US FTC approval of the takeover, Panasonic agreed to sell Sanyo's portable NiMH battery business to Fujitsu subsidiary FDK in order to preserve competition,[5] and later did so.

[6][5] Panasonic retained the "Eneloop" trademark, sourcing the batteries from FDK (formerly Sanyo) factories.

The thin insulators allowed significant leakage, leading to relatively short self-discharge times.

[1] The trade-off was modified for the Eneloop Pro series, providing higher capacity but with more self-discharge and shorter lifespan.

The more expensive Eneloop Pro has significantly higher capacity and is suitable for higher-current applications, but has poorer charge retention and shorter lifespan in charge cycles; total lifetime capacity in watt-hours is much less than the other versions.

Due to reduction of the capacity compared to the regular Eneloop cells, the charging time is halved for the AA and reduced by 25% for the AAA.

The reduction in capacity also reduced the production cost, which decreased the initial investment for rechargeable batteries.

According to Panasonic, it can now be recharged up to 3,000 times (life cycles for DOD 60%)[14] (model numbers BK-3LCC for the AA and BK-4LCC for the AAA battery).

Packaging is marked prominently 'Best for DECT' certainly in European markets, suggesting that these batteries are suitable for 'nearly always on charge' applications such as home cordless phones.

The Eneloop Pro family have higher capacity in mAh, trading this off against poorer charge retention and shorter lifespan.

They retain 75% of their initial charge after one year, and can be recharged 500 times, significantly less than the standard non-Pro Eneloop line.

Eneloop Plus cells have a PTC thermistor built-in that cuts the power in case of overheating.