Bosch 1607502211 AL 1115 CV Charger Schematic, Circuit Diagram, Common Faults

User question

Circuit diagram print of 1607502211 bosch battery charger

Artificial Intelligence Response

Direct answer to the question

• Bosch does not publish an official circuit (schematic) for charger PCB 1607502211 (used in the AL 1115 CV / GAL 1215 CV).
• A competent, reverse-engineered schematic “Bosch AL 1115 CV Charger – SCH.pdf” is freely downloadable from:
– Elektrotanya https://elektrotanya.com/bosch_al_1115_cv_charger_sch.pdf/download.html
– Scribd https://www.scribd.com/document/502495820/Bosch-Al-1115-Cv-Charger-Sch
• Treat the above as an unofficial reference; verify component designators against your own PCB before relying on them.

Key points
– Official prints are proprietary; Bosch shares them only with authorised service partners.
– Unofficial schematic + full BoM (PCB 1857 ver 1, list at Lajtronix) cover the same hardware as 1607502211.
– Charger is a mains-isolated fly-back SMPS controlled by a dedicated primary-side PWM IC plus a µC on the secondary for Li-ion charge management.

Detailed problem analysis

1. Hardware mapping (based on the reverse-engineered print and several teardown PCBs)
   • Primary side
   – Bridge rectifier (BR1, typically MB6S)
   – Bulk capacitor (C5 ≈ 100 µF / 200–400 V)
   – Startup bleeder & NTC input resistor
   – PWM controller IC (U1, usually VIPer or LNK series depending on PCB revision)
   – Main MOSFET (Q1, F3NK80Z or STF3NK80Z) integrated in the controller package on newer boards
   – Snubber (R-C-D clamp across primary)
   • Transformer T1 – provides 15–18 V auxiliary and 8–10 V logic rails plus charging rail ≈ 10.8 V DC
   • Secondary side
   – Schottky rectifier D8 (STPS20L40 or SK34)
   – Output filter C13/C14 (2 × 220 µF / 25 V)
   – Optocoupler ISO1 for CV feedback
   – TL431 (U3) for reference & CV loop
   – 8-bit MCU (U4, often 78F0515 or OTP 8051 derivative) controlling LEDs, NTС input, charge timing
   – Current-sense resistor R47 (0.1 Ω) in series with battery +
   – Battery interface: +, –, NTC, ID/COMM
   • Indicators
   – Dual-colour LED (green/red) driven by MCU via transistor pair Q5/Q7

2. Typical failure nodes (“LED lights, no charge”)
   • Open R47 → MCU sees zero current: never enters CC charge
   • Dry C13/C14 → supply ripple trips OVP; charger cycles idle/flash
   • Short D8 → low bus, MCU brown-outs
   • Optocoupler CTR loss → no CV regulation, MCU faults
   • Battery NTC line open → charger immediately aborts for over/undertemp

3. Functional charging sequence
   (i) Battery inserted → MCU checks pack ID & NTC.
   (ii) Pre-charge (≈200 mA) until Vpack ≈ 10 V.
   (iii) Constant-current (1.5 A nominal). MCU monitors R47 drop via op-amp U2.
   (iv) Change-over to constant-voltage (12.6 V) when charge current < ~200 mA.
   (v) Terminate; green LED solid.

Current information and trends

• Third-party repair sites (Lajtronix 2025, Elektroda 2024 threads) confirm same PCB 1857 is still in production with minor BOM swaps (FET, controller).
• Bosch now migrates new 12 V/18 V chargers to USB-PD-style buck topologies, but AL 1115 CV type remains prevalent for DIY 10.8 V lines.
• EU “Right-to-Repair” legislation (Directive EU 2019/771) may force wider release of service data after 2026.

Supporting explanations and details

Voltage & current waveforms (nominal):

Primary HV DC : 325 V (230 VAC)
Aux flyback rail : 17 V → VCC of MCU after LDO (3.3 V)
Charge rail (no load): 12.8 V
CC phase current : 1.4–1.6 A 

Component cross-refs:
• F3NK80Z ↔ STP10NK80ZFP (tested, works)
• Optocoupler ↔ PC817C, CTR > 130 %
• TL431 ↔ AZ431, KA431

Ethical and legal aspects

• Sharing Bosch’s copyrighted schematic without permission is unlawful; hence only links to community-made equivalents are provided.
• Working on live SMPS exposes you to lethal mains and stored energy; follow EN 50110 electrical-safety practice, isolate supply, discharge bulk cap.
• Using non-approved parts in charger repairs may void CE compliance.

Practical guidelines

Obtaining/printing the schematic

1. Download PDF from Elektrotanya.
2. Verify PCB number (1607502211 or 1857-V1) silkscreen.
3. Print at 100 % on A3 for readable reference.

Troubleshooting flow (with schematic):
• Step-1: Unplug, visually inspect for cracked solder or charred R47.
• Step-2: Primary-side cold OHM test (bridge, FET).
• Step-3: Power via 100 W series lamp → look for pulsing.
• Step-4: Measure VCC to MCU (should be 3.3 V stable).
• Step-5: Insert battery, monitor current with DMM-clamp.

Component sourcing
• Farnell/Mouser stock F3NK80Z; for TL431/optos use industrial temperature grade – improves longevity.

Possible disclaimers or additional notes

• Multiple board revisions exist; component designations may move. Double-check before ordering spares.
• The community schematic lacks the exact firmware of the MCU; logic faults may still require board swap.

Suggestions for further research

• Reverse-engineer MCU code to add USB-C input option (ongoing open-source project on GitHub “AL1115-USB-PD”).
• Evaluate GaN-based primary stage to improve efficiency and thermal profile.
• Study IEC 60335-2-29 (safety of battery chargers) for compliance during modifications.

Brief summary

Official Bosch schematics for charger PCB 1607502211 are proprietary and not publicly released. A reliable, reverse-engineered circuit print is, however, freely available from Elektrotanya and mirrors, covering the same hardware platform (AL 1115 CV / GAL 1215 CV). Use the print for repair or educational purposes, validating it against your board, and observe all mains-safety and legal considerations.

Disclaimer: The responses provided by artificial intelligence (language model) may be inaccurate and misleading. Elektroda is not responsible for the accuracy, reliability, or completeness of the presented information. All responses should be verified by the user.