Bosch is soon coming out with a new 6-bay 18V cordless power tool battery charger, model GAL18V6-8.
The new 6-port Bosch 18V battery charger is said to recharge a 4.0Ah battery to 80% in 32 minutes.
It features an 8-amp charging rate, for speedy charging of Bosch’s higher capacity batteries (and of course older standard packs), and has active cooling – a fan to help keep components at an optimized temperature.
This is a sequential charger, meaning it can only recharge batteries one at a time.
Bosch designed this charger with a 2-cycle process, with a fast charging cycle to 80% and then slow charging to top off the battery the last 20% to a full charge.
A fully discharged 4.0Ah battery will recharge to 80% in 32 minutes, and to a full charge in 50 minutes.
If you have Bosch 18V 4.0Ah batteries in each port, it will take up to 5 hours to fully recharge all of them, but 3.2 hours to charge them all to 80% – IF the charger is set to only fast-charge as it recharges multiple batteries in order. Bosch’s product imagery doesn’t show controls that might allow for switching between fast and full charging, and their marketing language is unclear as to how the charger will behave with multiple batteries connect to it.
The new Bosch 6-bay Li-ion charger also has a top handle, for convenient carrying of the charger by itself or with a load of batteries, and a built-in cord wrap.
Size and Weight
- 11.92″ long
- 8.89″ tall
- 8.27″ wide
- Weighs 4.0 lbs
The charger is compatible with all Bosch 18V Li-ion batteries.
- Wide-looking base
- Top handle and cord wrap
- Fast charging rate
- Clear communications about battery charging order
- Reasonable price
- Sequential charging (and not simultaneous)
- Uncertain rechareging behaviors
I would have liked to have seen a pass-thru plug, like on Milwaukee’s M18 six-port charger. Bosch doesn’t describe the plug at all, suggesting it’s an ordinary plug and not a pass-thru. The benefit of a pass-thru is that you can connect something else – such as another charger – to the same AC receptacle, saving space.
An 8-amp charging rate is convenient, but can be confusing to end users. Bosch says that an 18V 4.0Ah battery fully recharges in 50 minutes.
It’s not a big deal that the charger takes 32 minutes to recharge a 4.0Ah battery to 80% and then another 18 minutes for the final 20%. But does this new charger allow for user controls to stop it at 80%?
Each bay sequentially charges a spent CORE18V 4.0 Ah battery to 80% in 32 minutes and full in 50 minutes.
But does this mean it charges a 4.0Ah to 80% and then to 100% and then moves on? Or does it charge a battery to 80%, move on to the next, and then tops all of the batteries to 100% of the user hasn’t removed them yet.
That is, which recharging behavior is true? For two batteries, how does the charger work?
- Battery 1 to 80%
- Battery 2 to 80%
- Battery 1 to 100%
- Battery 2 to 100%
- Battery 1 to 100%
- Battery 2 to 100%
Option 1 would be a big deal, if the batteries all charged to 80% and then topped off after that, but, as Bosch only describes the charging rate for a single battery, there’s indication that it does this.
I have a Sony camera battery charger, and it has “normal” charging mode, which fast charges the battery to partial capacity, and “full” charging mode that does the same but then tops it off for maximum charge capacity.
Many cordless power tool brands’ battery chargers have 80% indication – or thereabouts – where it will blink a different color when charging, when mostly charged, and then when complete.
80% indication would be convenient on any charger, but on a sequential charger it would be much more convenient if the charger could stop at 80% and then move on to the next battery.
Bosch’s official product imagery doesn’t show any buttons or user controls where you can change the charging settings in any way, nor is there any commentary about any user interface.
We’ve asked Bosch PR for clarification and are waiting for their response.
In my opinion, this would be a hugely impactful feature, if the charger was able to charge each battery to 80% and then start a series of top-off cycles. If you can connect 4.0Ah batteries to every port, taking advantage of only the quick charging cycle would result in all 6 batteries being charged to 80% in around 3 hours and 12 minutes. If each battery must go through quick charging and slow top-off cycles, the total charging time increases to 5 hours.
The biggest benefit of a sequential charger is to recharge multiple batteries without having to watch over and swap batteries in a single charger.
Let’s say the charger operates in the first manner described above, where it charges each battery to 80% before moving on. After 2 hours into the 5 hour charging sequence, you 3 batteries charged to 80% and a fourth nearly there. If the charger operates where each battery is recharged to 100% before moving on to the next battery, you will have 2 fully charged batteries and the third halfway there. This is all assuming 4.0Ah batteries. The effect will be multiplied with higher capacity batteries.
That top-off charge extends the charging rate of a 4.0Ah battery by 56% to get you the last 20% of charge capacity.
Now, think about how long sequential charging will take if you have even higher capacity batteries. If things are proprotionate, an 8Ah battery might take 64 minutes to fast-charge to 80% and 100 minutes total to get to 100%. And if you have 6 batteries connected, that’s an extra 36 minutes per battery for the top-off charge.
Why would Bosch mention the 2-cycle charging behavior if the charger could only charge each battery to 100% before moving on? As mentioned, we’ve asked Bosch for clarification, and hope they can clear things up.
Maybe Bosch is also working on a simultaneous 4-bay or 6-bay charger?
Or maybe an 18V + 12V multi-port charger? They came out with a 12V/18V charger back in 2017, and I was hoping that would become standard, similar to how Dewalt and Milwaukee all have multi-volt chargers.
Some Bosch 18V users will love this new 6-bay charger, but others will lament that it’s a sequential charger rather than a simultaneous charger capable of 2 or more concurrent charging cycles.
What do you think?