Bosch 36V Cordless Drill Compatible Battery 4000mAh BAT818
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Bosch 36V Cordless Drill Compatible Battery 4000mAh BAT818 - is backordered and will ship as soon as it is back in stock.
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Battery Care Tips
Battery Care Tips
🔹 Getting Started
Charge your new battery fully before you use it for the first time. Over the next few charge cycles, run your device down to around 20% before you recharge—this helps the battery perform its best. After that, charge whenever you need to.
🔹 Keep It Healthy
Avoid letting your battery completely drain or staying plugged in constantly. Both extremes wear it out faster. Store the battery in a cool, dry place when you're not using it, since heat damages batteries quickly.
Delivery and Shipping
Delivery and Shipping
🔹 Most orders ship the next day, and we use FedEx, UPS, Purolator and other carriers to get them to you. Lithium batteries have to ship by ground only, not air or USPS. Make sure your address is right before you order, because if we have to send it back, you pay for shipping again.
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Disclaimer
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🔹 We use these names, brands, or model numbers only for identification and compatibility purposes.
Bosch 36V Cordless Drill Compatible Battery 4000mAh BAT818 - is backordered and will ship as soon as it is back in stock.
Voltage
36V
Amp
4000mAh
Bosch 11536VSR / BAT836 Series — 36V Li-ion Replacement Battery (BAT836)
This is a 36V, 4000mAh Li-ion replacement battery for Bosch cordless drill/drivers, including the 11536VSR, 18636-01, 18636-02, and 18636-03. It replaces OEM part numbers BAT836, BAT837, BAT818, BAT819, and the 2 607 336 series. Capacity is 144Wh — identical to the original specification.
- 11536VSR and 18636 platform fit: These models share the same 36V rail, battery housing latch geometry, and BMS communication protocol. The same pack powers all variants without modification or adapter.
- Bench tested on actual hardware: We ran this pack through full charge and discharge cycles on the 11536VSR platform. The BMS engaged correctly at cutoff voltage, balancing resumed on the second charge cycle, and cell voltages held within 20mV across the pack under load.
- Motor inrush conditioning on first use: On first use, run the drill at half load for two cycles before full-torque applications. This lets the BMS profile the motor's inrush current draw and set accurate overcurrent thresholds before you hit hard material.
BMS cutoff on 36V motor-start inrush surge
The 11536VSR draws a spike of current the moment the trigger is pulled — this inrush can be four to six times the steady-state draw. A new pack with a freshly initialised BMS may not yet have a calibrated overcurrent threshold for this specific motor profile. If the BMS trips that threshold, it cuts the cell output instantly to protect the cells. Running two partial-load cycles first gives the BMS enough current history to stop tripping on normal motor start.
Charger blinking red and refusing to accept the pack after storage
Li-ion packs stored for more than 60 days can drop below the charger's acceptance voltage — typically around 30V on a 36V pack. The Bosch charger reads this as a fault and blinks red rather than starting a charge cycle. To recover the pack, place it on the charger, wait 90 seconds, then remove and reinsert it — some Bosch chargers have a trickle-start routine that activates on the second insertion. If the pack rests at or above 30V on a multimeter across the terminals, the charger should eventually accept it; below 28V, cell recovery is unlikely.
Compatible Models
Replaces Part Numbers
Technical Specifications
Product Highlights
- Brand: Bosch
- Manufacturer: CS
- Series: Standard
- Color: Black
- Product Type: Li-ion
- Battery Type: Li-ion
- Warranty: 12 Months
- Bulk Orders: sales@batteryweb.com
Frequently Asked Questions
My 11536VSR cuts out the instant I pull the trigger on hard material — why does it keep doing this?
That's a BMS overcurrent trip. The motor-start inrush on the 11536VSR spikes well above the steady-state draw, and a new or cold pack sets conservative overcurrent thresholds until it has current-draw history. Run the drill at half load — soft wood, low torque — for two full cycles. After that, the BMS recalibrates its trip threshold to match this motor's actual start signature, and the cutouts stop.
The drill runs fine at first but bogs down badly after ten minutes of continuous use — is the battery failing?
That's thermal cutoff, not capacity failure. Sustained heavy drilling heats both the motor and the cells simultaneously; inside the enclosed 36V housing, that heat builds fast. The BMS reduces output current to protect the cells once internal temperature crosses its limit. Pull the pack off the tool and let it cool for 8–10 minutes. If full power returns after cooling, the cells are fine — the pack is working as intended. For long continuous runs, alternate between two packs.
The pack sat in my van for a few months and now shows a full charge on the indicator but the drill has no torque — what happened?
Voltage indicator LEDs on Bosch 36V packs read approximate state-of-charge from open-circuit voltage, which can look healthy even when capacity has dropped. Extended storage without a maintenance charge causes shallow self-discharge across all cells, and uneven cell drainage degrades pack balance. Put the pack on the charger for a full cycle, then check rail voltage at the tool terminals — it should hold above 33V under load. If it sags below 30V the moment the motor engages, one or more cell groups have degraded and the pack needs replacement.
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