Battery Instructions

Within 10 days of purchase, it is mandatory to check the charging voltage of the electric relay at a Rombat partner service center (where available) or at a RAR-authorized service center in locations without a Rombat partner.

The voltage must be within 14 - 14.4 V. If the charging voltage is outside this range, please correct the issue. The certificate becomes valid only when the voltage is correct and noted accordingly.

Charging voltage check is free of charge both at the time of purchase and during the warranty period, at service centers authorized by Rombat and listed in the warranty certificate.

Batteries delivered with electrolyte should be stored in closed, dry rooms with proper ventilation, temperatures between 5 and 30°C, and relative humidity below 80%, away from heat sources and sunlight. After a maximum storage or inactivity period of:

Disconnect all electrical consumers

Clean the battery terminal and cable lug contact surfaces of oxides until a metallic shine appears

Secure the lugs firmly on the terminals without causing mechanical damage

Only use proper cable lugs for good electrical contact

Disconnection order: first the ground (negative) terminal, then the positive terminal

Connection order: first the positive terminal, then the ground (negative) terminal

In vehicles with 24VDC power systems, both series-connected batteries must be structurally identical, functional, and equally charged (same voltage and electrolyte density)

It is strictly forbidden to connect 12V consumers directly to the terminals of either battery in 24VDC systems

Use a 24VDC/12VDC converter to power such consumers

We recommend battery checks at the beginning of the cold season, free of charge at any partner service center.

These are maintenance-free batteries; any intervention in the battery construction is prohibited.

Also, check that the vent holes in the caps are not blocked.

If overcharging is observed (indicated by high electrolyte consumption or drop in level), or undercharging (voltage below 12.5V and electrolyte density below 1.25g/cm³), check the vehicle's electrical system (regulator relay, alternator) and recharge the battery promptly.

City driving with frequent starts and short trips (e.g., taxis) can drain the battery faster, even if the system is working properly.

Never leave a discharged battery (under 12V and 1.2g/cm³) at temperatures below 0°C—electrolyte may freeze and damage the plates! Relay voltage must be maintained at (14.2 ± 0.2 V).

Avoid prolonged use of batteries under 70% charge—it leads to capacity under-dimensioning and overload failure (warranty void).

Recharge using a charger any battery in one or more of the following conditions:

Accidentally discharged battery (below 75%)

Stored battery at the end of the storage interval defined in the "Storage" section

Discharged battery claimed as defective, before visiting a service center

Charging can generally be performed using any commercial DC charger capable of delivering: 13.5V ≤ Output Voltage ≤ 16.5V and 4A ≤ Output Current ≤ 25A

Typically, charging is done with a current of approx. (5–10)% of Cn (A), until uniform gas release occurs and electrolyte density stabilizes around 1.28 ± 0.01 g/cm³

Toward the end of charging, terminal voltage reaches 15.80–16.50V at 25°C (in charger mode). During charging, battery caps must be removed. Recharging is best done in specialized workshops.

Warning:
For AGM or GEL batteries, charging voltage must remain within 14.4V–14.8V. Do not exceed this limit to avoid overcharging!