Brand: Bosch

This replacement battery compatible with Bosch Professional 18V cordless tools (GBA, BAT618, BAT620, GSR, GSB, GBH) lets you restore your device's original runtime when the fitted battery weakens. Capacity of 5.0 Ah. Check your original battery reference and the exact model of your device before buying to ensure compatibility.

In-depth reviewRead our full review → 3.0/5 This compatible 18V 5Ah battery targets Bosch Professional tools at a price around 25% below the genuine part, and its mount fits normally across the whole range, with no reported jamming on a recent tool. The real point of attention is real-world capacity: on similar compatible Bosch batteries in the same price bracket, the capacity actually delivered typically sits between 50 and 65% of the figure on the box, a gap far more severe than simple marketing optimism. No independent test exists for this exact reference, but it uses the same generic, unbranded cells as the products compared, and cuts out sooner than a genuine one under heavy load. A handful of negative flags with no detail show up on the retailer's page, too small a sample to draw firm conclusions. For occasional use on a tight budget, it remains an option; for daily professional use, the reliability gap is worth weighing against the money saved.

Bosch supplies a large share of Europe's original-equipment starter batteries, which lends particular weight to its chargers. The C30 sits at the centre of the C-Line range: 3.8 amps, 6 and 12 volt support, and a stated capacity of up to 120 amp-hours, covering the overwhelming majority of passenger cars including large-battery diesels. It handles the recent technologies, EFB and AGM included, found on every stop-start vehicle. Charging is electronically controlled and switches to trickle mode once the battery is full, with no intervention needed.

In-depth reviewRead our full review → 3.5/5 There is a simple reason the C30 has become the shelf reference: Bosch understands batteries better than anyone, since the supplier builds them for half of Europe's carmakers. That expertise shows on one specific point, the handling of EFB and AGM batteries. These technologies now fit every stop-start vehicle, they demand specific charging voltages, and many cheap chargers treat them as ordinary lead-acid, which shortens their life. The C30 applies the right profile. The second argument is admissible capacity: 120 amp-hours, where most chargers of this size stop well short. In practice it is not limited to the city car, it also copes with the large diesel saloon and the family MPV. At 3.8 amps charging stays slow on a deeply flat battery, but that is the very principle of this class of device: gentle charging wears the plates less than a brutal one. In use the housing is sturdy, the clamps are decent, and the supplied carrying case saves you from finding tangled cables in a corner of the garage. Two honest remarks. Status reporting is limited to indicator lights, with no screen: you know roughly where charging stands, not to the percentage, which the Einhell CE-BC 4 M displays for a good fifteen pounds less. And like most lead-acid chargers, it does not handle LiFePO4 lithium. At fifty pounds it is a purchase of peace of mind rather than a bargain, but the reliability is there.

The C70 tops Bosch's C-Line range and stands apart on two counts its siblings cannot match. First 24 volts, essential as soon as you leave the passenger car behind: trucks, coaches, agricultural machinery and many boats run on two batteries in series. Then 10 amps, which cut charging time threefold against a 3.8 amp model. It keeps the modern EFB and AGM battery support and adds a function workshops value: keeping the vehicle live while its battery is replaced, so no electronic setting is lost.

In-depth reviewRead our full review → 3.9/5 The C70 targets a specific audience, and it should be said plainly: if you only have a passenger car in the garage, it is overkill and the C30 will do. Its interest begins as soon as the fleet diversifies. The 24 volt capability first opens the door to trucks, tractors, dual-circuit motorhomes and a large share of motor boats, all fitted with two batteries wired in series. No other charger in our selection can do that. The 10 amps then change your relationship with time: a half-empty 100 amp-hour battery recharges in half a day rather than a full night, which matters when the vehicle has to leave. The function we find cleverest is aimed at workshops. On a recent car, disconnecting the battery wipes the memories of the ECU, the radio, sometimes the electric windows, which then need resetting. The C70 can power the onboard circuit during the operation, much like a stabilised power supply, and the battery is swapped without losing anything. That is a service normally charged for by far dearer equipment. Two reservations. Status reporting stays basic, with indicator lights where a screen would be welcome at this price. And it does not handle LiFePO4 lithium, which is starting to be limiting on recent motorhomes. At just under eighty pounds it is a considered investment for anyone maintaining several vehicles, and a pointless one for a single city car.

The ProCORE18V 8.0Ah is the high-capacity reference in the Bosch Professional 18V range: two layers of 21700 cells deliver up to 87% more power than a conventional battery and 50% more runtime than the ProCORE18V 4.0Ah. CoolPack 2.0 technology dissipates heat faster and promises up to 135% longer lifetime than a standard Bosch 18V pack. Compatible with the whole 18V Professional ecosystem, CORE18V and older tools alike, plus PROFACTOR tools and the AMPShare alliance. Its taller body does not fit a few compact tools.

In-depth reviewRead our full review → 4.0/5 On our tester's bench, this ProCORE18V 8.0Ah replaced a 4.0Ah that was starting to feel short on the angle grinder and the reciprocating saw: the extra grunt is obvious from the first cut, with no drop-off even on the most current-hungry PROFACTOR tools. Runtime is the real selling point, echoed by most UK reviews on this exact battery: a full day of drilling and cutting without going back to the charger. The flip side of that capacity is size: the pack is noticeably taller and heavier than a 4.0Ah, and it will not fit a few compact tools such as some older corded-style circular saws, worth checking if you already own smaller CORE18V packs. Paired with the GAL18V-160C fast charger, it reaches 80% in around 32 minutes, genuinely useful on a busy site, though an older 18V charger will take a lot longer, over an hour and a half by some accounts. The one gripe that comes up again and again is price, well above a standard 18V pack. For anyone running Bosch 18V tools all day, this remains our default pick above 6.0Ah.