The organization of comfortable parking on the water is impossible without reliable anchor pumpBut the weakest link in the chain is often not the compressor itself, but the power source, and many water-engineers are faced with a situation where the declared operating time is barely enough for half the cylinder, which makes preparation for the alloy into anguish.
Well-chosen battery This ensures stable pressure throughout the pumping cycle, prolongs the life of the pump and ensures that you do not stay on shore with a half-empty boat. In this article, we will discuss the technical nuances that will help you avoid mistakes when buying.
The main problem lies in the fact that manufacturers often specify ideal specifications, not taking into account the real conditions of operation on the water: temperature changes, vibration and high humidity. Battery capacity This is only one side of the coin, no less important is the initiation current and chemical composition.
Calculation of power consumption and battery capacity
Before you go to the store for a new one. feed-inA standard PVC boat electric pump consumes between 10 and 20 Amps per hour, but at launch or when operating under high loads (such as high winds), current can jump to 30-40 Amps for a short time.
If you plan to pump the boat regularly, consider installing a battery with a margin of capacity. Using a "stretching" battery leads to a deep discharge, which is critical for lead-acid models. Depth of discharge more than 50% for a standard AGM battery reduces its lifespan by 3-4 times.
To calculate the minimum capacity required, use a simple formula: multiply the current pump consumption by running time. For example, if the pump consumes 15A and runs for 20 minutes (0.33 hours), you will need about 5 Ah. However, given the losses during peak loads, it is recommended to take the battery at least 12-15 Ah.
It's important to consider the stress under load. When you're under a lot of discharge, the voltage drops. pump-motor It starts to work less efficiently, consumes even more current, and this creates a vicious circle that quickly drops the weak battery.
Technology comparison: AGM, GEL and LiFePO4
The market offers several main types batteryThe choice between them depends on the budget and frequency of use of the boat. Traditional lead-acid models with liquid electrolyte (WET) are best avoided due to the risk of acid leakage and maintenance.
AGM (Absorbent Glass Mat) technology is the gold standard for water transport, and the electrolyte in these batteries is sealed and absorbed into fiberglass, making them completely sealed and safe. They hold the initiating current needed to start. pump-engine.
Lithium-iron-phosphate batteries (LiFePO4) are the modern top-end segment, they are much lighter than lead analogues (by 3-4 times) and allow you to use up to 90-100% of their capacity without harm to chemistry.
- 🔋 AGM/GEL: Optimal value for money, resistance to vibration, do not require maintenance, but have a lot of weight.
- ⚡ LiFePO4: Minimum weight, huge cycle life (2000+), stable voltage, but high initial price and the need for BMS.
- 🚗 Automotive starters: Cheap, but afraid of deep discharge, can emit gases and require vertical installation.
For most owners of PVC boats, the best choice will be traction-carrierIt will forgive the errors in operation, withstand the shaking when transported in the trunk and provide sufficient power.
Why not use a car battery starter?
Car batteries (SLIs) are designed to give off a short-term huge current to start the engine, then immediately charge from the generator. At the deep discharge characteristic of pump operation, the plates in them quickly sulfate and collapse.
Protection against moisture and operating conditions
Water and electricity are dangerous combinations, especially when it comes to salt water or splashing with a wave. IP65 You can't neglect the extra protection, and corrosion of the contacts is the main reason for the failure of the power system on the boat.
It is recommended to use special sealed boxes or batteries in a plastic case with a lid. When installed in an open form, be sure to process the terminals. solid-grease Or a spray to protect the contacts, which will prevent oxidation and loss of stress.
⚠️ Warning: Never leave the connected battery in direct sunlight for long periods of time. Overheating the case above +50C can cause the valves to depressurize and the battery to fail.
Storage is also important: If you are putting the boat away for the winter, the battery must be removed, fully charged and stored at room temperature, periodically (once every 3-4 months) conducting a charge-discharge control and training cycle.
For lithium batteries, the requirements are even stricter: they cannot be stored fully discharged or fully charged at low temperatures. LiFePO4 It's 60-70%.
Switching and selection of wire cross-section
Many people forget that the quality of the connection and the thickness of the wires directly affect the efficiency of the pump. Thin wires create resistance that turns into heat, "eating" the precious energy of the battery. Standard wires, which come with cheap pumps, often have a cross section of less than 1.5 mm2, which is critically small.
For currents in 15-20 Amps, the minimum permissible cross-section of the copper wire is 2.5 mm2, and for comfortable operation and minimization of losses, it is better to use 4 mm2. The length of the wires also matters: the longer the cable, the larger its cross-section should be.
☑️ Electrical circuit inspection
Use quality connectors, such as quick-removal contacts of the type SB Anderson Power Products, or reliable screw terminals, twists and tape on a boat are guaranteed corrosion and loss of contact at the most inopportune time.
If you build the system yourself, be sure to install a fuse on the plus wire as close to the battery as possible, which will save the boat from fire in the event of a short circuit.
| Current (A) | Wire length (m) | Min. section (mm2) | Recommended section (mm2) |
|---|---|---|---|
| 10 A | 2m | 1.5 | 2.5 |
| 15 A | 2m | 2.5 | 4.0 |
| 20 A | 3m | 4.0 | 6.0 |
| 30 A | 3m | 6.0 | 10.0 |
Chargers: nuances of recovery
Choosing the right charger (ROM) prolongs battery life. Lead batteries (AGM/GEL) require a voltage-restricted mode that automatically switches to storage mode. Recharging is disastrous for them: the electrolyte boils out and the battery swells.
Modern “smart” chargers have microprocessor control, which analyzes the state of the device. battery And it chooses the optimal algorithm: desulfation, primary charge, saturation and buffer mode. Using simple transformer charges by eyeball, gradually kills expensive equipment.
Lithium batteries (LiFePO4) require specialized charge profile RAMs CC/CV (Constant Current / Constant Voltage) and precise cut-off voltage (usually 14.4-14.6V for 12V battery) Charging lithium with a lead charger is dangerous and can lead to fire.
Use temperature-compensated chargers. If you charge your battery in a cold garage or in the heat, the charge voltage must be adjusted automatically to avoid under- or over-charging.
Common mistakes in selection and operation
One of the most common mistakes is trying to use charger They are not designed to be used for long periods of loading and can quickly fail or overheat.
They also often ignore the compatibility of connectors, and by buying a pump with thin wires and connecting it to a powerful battery through adapters, users create a "bottleneck," which causes the pump to fail to develop its declared power, and the adapters to warm up.
⚠️ Warning: Do not use damaged batteries with a swollen body or traces of electrolyte on the terminals. Operation of such a battery can lead to a short circuit and a fire on the boat.
Another mistake is to store a battery that is dead, and if you leave the battery dead for six months, the probability of recovery is close to zero, especially if you're talking about lead-acid technology.
The right wire cross section and the use of a quality charger are more important than overpaying for the battery brand.
FAQ: Frequently asked questions
How long does the pump from the battery 12V 20Ah work?
With a pump of about 15A, a 20Ah battery would theoretically last about 1 hour and 20 minutes, but given the efficiency and inadmissibility of deep discharge, the real safe operating time would be about 40-50 minutes, which is usually enough for 2-3 full pumping cycles of a PVC boat.
Can I charge the AGM battery with a conventional car charger?
You can, but only if the charger has a manual voltage regulator and you can control the process, not allowing exceeding 14.4-14.7V. Automatic "boilers" without switching to AGM mode can recharge the battery, which will lead to its deterioration.
Which battery is better for seawater?
Seawater is critically tight, and plastic case batteries (ABS plastics) are best suited to AGM or GEL technology. Lithium batteries are also sealed, but require more careful protection from salt corrosion.
Why does the pump hum but not pump when connected to the battery?
The battery is probably very discharged and cannot produce the necessary initiation current, or the interconnection wires are too small, and the voltage at the pump inlet drops below a critical level, and there may be a mechanical failure of the pump itself.