The Güde V 421 C is a professional battery charger and starter for workshop use, compatible with lead-acid (PB) and wet (WET) batteries at 12 V and 24 V with a capacity of 20 to 800 Ah. Effective charging current 60 A, jump-start assistance up to 390 A at 0 V, interference-free analogue ammeter, thermal protection and reverse polarity protection. Made in Germany by Güde, founded in 1970. Distributed in Italy by Krollit, official Güde distributor since 2007.
- Item code: 85074
- Output voltage: 12 V / 24 V (selectable)
- Effective charging current: 60 A
- Compatible battery capacity: 20–800 Ah
- Jump-start at 1.5 V: 240 A
- Jump-start at 0 V: 390 A
- Battery start without pre-charge: 35–50 Ah
- Battery start with pre-charge: 65–100 Ah
- Mains power: 8,000 W
- Power supply: 230 V / 50 Hz
- Mains fuse: 16 A (slow-blow)
- Fuses included: 10 x 50 A (2 x 50 A fuses for the rectifier)
- Connecting cable: 2 m
- Net weight: 15.9 kg
- Dimensions (L x W x H): 330 x 250 x 600 mm
- Certifications: CE, TÜV Süd
Who uses the V 421 C and for what
The Güde V 421 C is used by mechanical workshops and body shops that need to charge, fast-charge and start vehicles with 12 V batteries (cars, vans) and 24 V batteries (trucks, buses, construction machinery). The 800 Ah capacity covers almost all batteries fitted to heavy commercial vehicles. With 390 A of jump-start assistance at 0 V, it can start vehicles with a completely flat battery. The two 50 A fuses included in the rectifier and the 10 spare fuses make the device immediately operational without additional purchases. Transport around the workshop is made easy by the two large wheels.
Logistics and Krollit support
Shipping 5–9 working days (7 days for southern Italian regions). Technical assistance in Italian available for the entire product lifetime. Original Güde spare parts available from Krollit stock, Monteforte Irpino (AV).
Who is the V 421 C for
| Profile | Suitability | Reason |
|---|
| Mechanical workshop with 12 V and 24 V vehicles | Suitable | The 12 V / 24 V selector, capacity up to 800 Ah and 390 A jump-start cover cars, vans, trucks and construction machinery with a single device. |
| Body shop or car wash requiring fast charging | Suitable | The 60 A effective charging current enables fast charging and charge maintenance during work without immobilising the vehicle for long periods. |
| Occasional home use or private garage | Not suitable | At 15.9 kg, 8,000 W mains power and a 16 A fuse, the V 421 C is sized for continuous professional use; for home use, automatic chargers of 10–20 A are more appropriate. |
Not suitable for: lithium batteries (LiFePO4, Li-Ion) — the V 421 C is compatible only with lead-acid (PB) and wet (WET) batteries; occasional home use where the power and size are excessive; environments without a 230 V / 16 A outlet.
Technical specifications
Power supply and charging
| Mains voltage | 230 V / 50 Hz |
| Mains fuse | 16 A (slow-blow) |
| Mains power | 8,000 W |
| Output voltage | 12 V / 24 V |
| Effective charging current | 60 A |
| Compatible battery capacity | 20–800 Ah |
| Battery types | PB (lead-acid, including MF), WET (wet cell) |
Jump-start assistance (emergency starting)
| Jump-start at 1.5 V | 240 A |
| Jump-start at 0 V | 390 A |
| Battery start without pre-charge | 35–50 Ah |
| Battery start with pre-charge | 65–100 Ah |
Safety and protection
| Thermal protection | Yes |
| Reverse polarity protection | Yes |
| Rectifier fuses included | 2 x 50 A |
| Spare fuses included | 10 x 50 A |
| Battery terminals | Fully insulated |
| Certifications | CE, TÜV Süd |
Dimensions and weight
| Length | 330 mm |
| Width | 250 mm |
| Height | 600 mm |
| Net weight | 15.9 kg |
| Gross weight (packed) | 17.2 kg |
| GTIN | 4015671850744 |
Standard equipment
- Güde V 421 C battery charger (item no. 85074)
- 2 m connecting cable with fully insulated terminals
- 10 spare fuses 50 A
- 2 x 50 A rectifier fuses (fitted)
- User manual and safety instructions
Original Güde spare parts
| Code | Description | Note |
|---|
| 85074-01001 | Axle | 1 pc — for versions FSL01 and FSL02 |
| 85074-01002 | Wheel | 2 pcs — replace as a pair |
| 85074-01003 | Handle | 1 pc |
| 85074-01004 | Rectifier | 1 pc — main electrical component |
| 85074-01005 | Rectifier fuse | 1 pc — replace after every rectifier intervention |
| 85074-01006 | Ammeter | 1 pc — analogue type |
| 85074-01007 | Fuse holder | 1 pc |
| 85074-01008 | Fuse set 50 A (2 pcs) | Replacement main fuses |
| 85074-01010 | Transformer | 1 pc — main component |
| 85074-01011 | Charge selection toggle switch | 3 pcs — charge mode selection |
| 85074-01014 | On/off toggle switch | 1 pc |
| 85074-01016 | 12 V / 24 V connector (complete) | 1 pc |
| 85074-01023 | 12 V / 24 V output cable | 1 pc |
| 85074-01024 | Ground cable | 1 pc |
| 85074-01019 | Support foot | 2 pcs |
Frequently asked questions
Is the Güde V 421 C compatible with lithium batteries?
No. The V 421 C is compatible exclusively with lead-acid (PB, including maintenance-free MF) and wet cell (WET) batteries. Lithium batteries (LiFePO4, Li-Ion, lithium AGM) require chargers with a dedicated charging profile.
Using the V 421 C on lithium batteries can cause irreparable damage and constitutes a safety hazard. Güde does not cover this type of use under warranty. Workshops servicing hybrid or electric vehicles with 12 V lithium service batteries should verify the battery chemistry before connecting any charger.
What is the difference between jump-start at 1.5 V and at 0 V?
Jump-start at 1.5 V delivers 240 A and is intended for partially discharged batteries (residual voltage of at least 1.5 V per cell, equivalent to approximately 9 V for a 12 V monobloc). Jump-start at 0 V delivers 390 A and enables starting even with completely flat or partially short-circuited batteries.
In a workshop, the 0 V function is essential for heavy vehicles (trucks, buses) that arrive completely dead after extended downtime. Pre-charging (65–100 Ah) before starting reduces stress on the rectifier and extends its service life. The Güde manual states that continuous jump-start assistance must not exceed 15 seconds without a cooling pause of at least 3 minutes.
How do you select the voltage between 12 V and 24 V on the V 421 C?
Selection is made via the dedicated toggle switch (spare part code 85074-01016 — 12 V/24 V connector complete). At 12 V, the unit works on passenger cars and light vehicles; at 24 V on heavy commercial vehicles, buses and construction machinery.
Always verify the battery's rated voltage before connecting the charger. The reverse polarity protection activates if the terminals are connected incorrectly, but does not replace prior voltage verification: connecting a charger set to 24 V to a 12 V battery can damage it within seconds if the protection does not activate in time.
How often should the fuses on the Güde V 421 C be replaced?
The 10 spare 50 A fuses included in the equipment are intended for replacing the two rectifier fuses (code 85074-01005) and the fuse holder (code 85074-01007). Rectifier fuses must be replaced every time they blow, without exception.
Güde recommends not replacing fuses with values other than the original 50 A: a fuse with a higher rating does not adequately protect the rectifier, which is the most costly component (code 85074-01004). Fuse replacement is the first maintenance operation to carry out before any other diagnosis in the event of no current output.
Are original Güde spare parts for the V 421 C available from Krollit?
Yes. Krollit holds original Güde spare parts for the V 421 C in stock, including the rectifier (85074-01004), transformer (85074-01010), ammeter (85074-01006), toggle switches and cables. Parts can be ordered by calling +39 0825-1494022 and quoting the 5-digit serial number prefix to confirm the correct FSL version (FSL85074-01 or FSL85074-02).
Note: the red terminal clamp (85074-01017) and black terminal clamp (85074-01018) are no longer available from Güde. For terminal replacement, contact Krollit to assess compatible alternatives. All other parts on the official list are available from stock or with short lead times.
