{"id":5158,"date":"2026-05-09T06:34:24","date_gmt":"2026-05-09T06:34:24","guid":{"rendered":"https:\/\/www.kmdpower.com\/?p=5158"},"modified":"2026-05-09T06:57:12","modified_gmt":"2026-05-09T06:57:12","slug":"how-to-size-a-12v-sodium-ion-battery-for-a-remote-solar-irrigation-pump","status":"publish","type":"post","link":"https:\/\/www.kmdpower.com\/cs\/news\/how-to-size-a-12v-sodium-ion-battery-for-a-remote-solar-irrigation-pump\/","title":{"rendered":"How to Size a 12V Sodium-Ion Battery for a Remote Solar Irrigation Pump"},"content":{"rendered":"

Sizing a battery for a remote solar irrigation pump is not just an amp-hour calculation. A reliable system must store enough usable energy, start the pump without BMS shutdown, and keep water moving when sunlight is weak or maintenance access is limited.<\/p>

Many off-grid pump failures happen because the battery is selected only by Ah. In real field conditions, the correct size depends on daily water demand, Total Dynamic Head (TDH), pump efficiency, startup current, usable Depth of Discharge, autonomy days, cable voltage drop, and temperature.<\/p>

A 12V sod\u00edko-iontov\u00e1 baterie<\/a><\/strong> can be a strong option for remote solar irrigation when the pack and BMS are properly designed. The battery still must match the pump, water schedule, charge controller, wiring, enclosure, and field environment.<\/p>

\"\"<\/figure>

Kamada Power 12V 100Ah Sodium ion battery<\/a><\/strong><\/p>

What Size 12V Battery Do You Need?<\/h2>

Pou\u017eijte tento vzorec:<\/p>

Battery Ah \u2248 Required Battery Wh \u00f7 System Voltage \u00f7 Usable DoD<\/strong><\/p>

If a pump needs 272Wh from the battery, the system is 12V, and the sodium-ion pack is designed around 90% usable DoD:<\/p>

272Wh \u00f7 12V \u00f7 0.90 = 25.2Ah<\/strong><\/p>

A properly specified 12V 30Ah sodium-ion battery<\/strong> may cover normal off-sun pumping. If the same system needs three cloudy-day autonomy, it may require around 12V 100Ah<\/strong> after adding field margin.<\/p>

Sizing Question<\/th>Required Input<\/th>Decision Impact<\/th><\/tr><\/thead>
How much water per day?<\/td>Liters or gallons<\/td>Defines total hydraulic work<\/td><\/tr>
How high is the lift?<\/td>TDH, not only vertical lift<\/td>Higher head increases Wh demand<\/td><\/tr>
When does the pump run?<\/td>Daytime, morning, night, cloudy backup<\/td>Determines battery-supported energy<\/td><\/tr>
How hard is startup?<\/td>Running current and startup current<\/td>Defines BMS peak rating<\/td><\/tr>
How many cloudy days?<\/td>Autonomy target<\/td>Drives backup capacity<\/td><\/tr>
What is the site condition?<\/td>Temperature, cable length, enclosure<\/td>Affects reliability<\/td><\/tr><\/tbody><\/table><\/figure>

Step 1: Start with Water Demand and TDH<\/h2>

Farmers usually start with water, not kilowatt-hours:<\/p>

How much water must be moved every day?<\/strong><\/p>

The key concept is Total Dynamic Head<\/strong>, or TDH. TDH is not just vertical lift. It includes the full resistance the pump must overcome.<\/p>

TDH = Static Lift + Drawdown + Pipe Friction + Pressure Head + Safety Margin<\/strong><\/p>

TDH Item<\/th>Co to znamen\u00e1<\/th>Why Users Underestimate It<\/th><\/tr><\/thead>
Static lift<\/td>Water level to discharge point<\/td>They use ground level instead of actual water level<\/td><\/tr>
Drawdown<\/td>Water level drop during pumping<\/td>Seasonal well changes are ignored<\/td><\/tr>
Pipe friction<\/td>Loss from pipe length, diameter, elbows, valves<\/td>Pipe loss is assumed to be zero<\/td><\/tr>
Pressure head<\/td>Pressure required by drip lines or sprinklers<\/td>System is sized only for open tank filling<\/td><\/tr>
Safety margin<\/td>Buffer for field variation<\/td>No room for aging or weather changes<\/td><\/tr><\/tbody><\/table><\/figure>

Two farms may both need 10,000 liters per day, but the farm lifting water 60 meters needs much more energy than the farm lifting water 10 meters.<\/p>

Step 2: Convert Water Volume and TDH into Watt-Hours<\/h2>

After you know water volume and TDH, estimate the energy required to move the water.<\/p>

Energy Required, Wh \u2248 Water Volume, Liters \u00d7 TDH, meters \u00f7 367 \u00f7 Pump Efficiency<\/strong><\/p>

Example: a remote cattle ranch needs to move 10,000 liters per day. TDH is 30 meters, and pump efficiency is 60%.<\/p>

10,000L \u00d7 30m \u00f7 367 \u00f7 0.60 = 1,362Wh<\/strong><\/p>

So the full daily hydraulic energy demand is about 1.36kWh per day<\/strong>.<\/p>

This does not always mean the battery must supply all 1.36kWh. In many solar pumping systems, panels run the pump during strong sunlight, while the battery only supports early morning, evening, cloudy intervals, or backup operation. If the system has a water tank, stored water can reduce battery size. If the system must pump during weak sunlight or at night, the battery must cover a larger share of demand.<\/p>

Step 3: Decide What the Battery Actually Needs to Cover<\/h2>

Do not size the battery from total daily water demand unless the battery must support total daily pumping.<\/p>

N\u00e1vrh syst\u00e9mu<\/th>Battery Role<\/th>Best Fit<\/th><\/tr><\/thead>
Solar direct + water tank<\/td>Small battery or no battery for normal pumping<\/td>Farms with enough daylight and tank capacity<\/td><\/tr>
Solar + battery backup<\/td>Covers morning, evening, and cloudy gaps<\/td>Remote farms needing reliability<\/td><\/tr>
Battery-backed scheduled pumping<\/td>Supports pumping whenever water is needed<\/td>Livestock, greenhouse, critical water supply<\/td><\/tr>
Battery replacing water storage<\/td>Carries most backup burden<\/td>Only when tank storage is difficult<\/td><\/tr><\/tbody><\/table><\/figure>

For the ranch example, assume solar panels handle most pumping during the day. The battery only supports early morning watering.<\/p>

If 20% of daily water demand must come from battery energy:<\/p>

1,362Wh \u00d7 20% = 272Wh<\/strong><\/p>

That 272Wh is the normal daily battery energy target. This is why a larger water tank can sometimes reduce battery cost. In agricultural pumping, water storage is often cheaper than electrical storage.<\/p>

Step 4: Convert Watt-Hours into 12V Amp-Hours<\/h2>

Battery capacity is usually sold in amp-hours, but pump work is calculated in watt-hours.<\/p>

Watt-hours = Amp-hours \u00d7 Voltage<\/strong><\/p>

For the example:<\/p>

272Wh \u00f7 12V = 22.7Ah<\/strong><\/p>

So the pump needs about 22.7Ah of usable battery energy<\/strong> for early morning pumping.<\/p>

Usable Ah is not the same as nominal Ah. A 12V 30Ah battery does not always provide 30Ah of practical field energy. The usable portion depends on chemistry, BMS settings, discharge current, temperature, aging, and the manufacturer\u2019s cycle-life rating.<\/p>

Step 5: Adjust for Usable Depth of Discharge<\/h2>

Depth of Discharge, or DoD, describes how much of a battery\u2019s nominal capacity can be used in normal operation.<\/p>

Typ baterie<\/th>Practical Design Assumption<\/th>What It Means for Pumping<\/th><\/tr><\/thead>
Basic lead-acid<\/td>Around 50% usable DoD<\/td>Needs larger nominal capacity; deep cycling shortens life<\/td><\/tr>
AGM \/ GEL lead-acid<\/td>Often 50\u201370%<\/td>Better sealed option, but over-discharge still hurts cycle life<\/td><\/tr>
LiFePO4<\/td>Often 80\u201390%<\/td>High usable capacity; low-temperature charging needs protection<\/td><\/tr>
Sod\u00edkov\u00e9 ionty<\/td>Often designed for high usable DoD<\/td>Strong for daily cycling, but verify datasheet, BMS, C-rate, and temperature limits<\/td><\/tr><\/tbody><\/table><\/figure>

For the sodium-ion example:<\/p>

22.7Ah \u00f7 0.90 = 25.2Ah<\/strong><\/p>

A properly specified 12V 30Ah sodium-ion battery<\/strong> can cover the normal early-morning load.<\/p>

Do not treat 90% DoD as universal. It must be confirmed from the battery datasheet. Rated cycle life, discharge rate, charging temperature, and BMS cut-off settings all matter.<\/p>

Step 6: Check Pump Startup Current Before Finalizing the Battery<\/h2>

A pump battery can have enough energy and still fail to start the pump.<\/p>

This usually happens because of rozb\u011bhov\u00fd proud motoru<\/strong>. A pump that draws 10A during normal operation may briefly require 30A, 50A, or more during startup. If the BMS cannot support that short peak, it may shut down. The user sees a confusing failure: the battery looks full, but the pump clicks, resets, or refuses to start.<\/p>

For many small 12V DC pump systems:<\/p>

Battery peak discharge rating should be at least 3\u00d7 to 5\u00d7 pump running current.<\/strong><\/p>

Field Symptom<\/th>Pravd\u011bpodobn\u00e1 p\u0159\u00ed\u010dina<\/th>What to Check<\/th>Corrective Action<\/th><\/tr><\/thead>
Pump clicks then stops<\/td>BMS peak current too low<\/td>Battery peak discharge rating<\/td>Use higher-peak BMS or lower-inrush pump<\/td><\/tr>
Battery looks full but pump resets<\/td>Voltage sag during startup<\/td>Cable length, gauge, connector loss<\/td>Use thicker cable or shorter cable run<\/td><\/tr>
Fuse trips at startup<\/td>Protection not matched to surge<\/td>Fuse rating and startup current<\/td>Use correct DC-rated protection<\/td><\/tr>
Pump starts only in strong sun<\/td>Battery cannot support surge alone<\/td>Battery peak output and SOC<\/td>Increase peak current capability<\/td><\/tr>
Inverter pump shuts down<\/td>Inverter surge not supported<\/td>Inverter surge and BMS rating<\/td>Match battery to inverter surge requirement<\/td><\/tr><\/tbody><\/table><\/figure>

Check BMS continuous current, BMS peak current, peak duration, cell C-rate, cable size, connector rating, fuse rating, and pump controller behavior. If the pump uses an inverter or AC motor, include inverter surge current in the design.<\/p>

Step 7: Add Autonomy Days for Cloudy or Monsoon Conditions<\/h2>

A system that works in good sun can still fail during cloudy days, winter, or monsoon season.<\/p>

Days of autonomy<\/strong> means how many days the battery can support required pumping with weak or limited solar input.<\/p>

Using the example:<\/p>

25.2Ah \u00d7 3 days = 75.6Ah<\/strong><\/p>

After adding aging margin, temperature margin, cable loss, and real-world usage variation, this would usually be rounded up to a 12V 100Ah sodium-ion battery bank<\/strong>.<\/p>

Sc\u00e9n\u00e1\u0159 aplikace<\/th>Suggested Autonomy<\/th>Pro\u010d na tom z\u00e1le\u017e\u00ed<\/th><\/tr><\/thead>
Garden or non-critical irrigation<\/td>1 day<\/td>Water delay has low consequence<\/td><\/tr>
Small farm or greenhouse<\/td>2 days<\/td>Crop stress risk exists<\/td><\/tr>
Livestock water supply<\/td>3 days<\/td>Water interruption is serious<\/td><\/tr>
Remote agricultural site<\/td>3\u20135 days<\/td>Maintenance access may be limited<\/td><\/tr>
Monsoon or winter low-sun region<\/td>5+ days<\/td>Solar recovery may be slow<\/td><\/tr><\/tbody><\/table><\/figure>

The right battery is not always the smallest battery that works on a sunny day. It is the battery that matches the cost of water interruption.<\/p>

Sodium-Ion vs Lead-Acid vs LiFePO4 for Solar Irrigation Pumps<\/h2>

The best battery chemistry depends on the site. In remote pumping, maintenance, usable capacity, partial charging, surge current, temperature, and replacement frequency often matter more than purchase price alone.<\/p>

Rozhodovac\u00ed faktor<\/th>Olov\u011bn\u00e9 kyseliny<\/th>LiFePO4<\/th>Sod\u00edkov\u00e9 ionty<\/th><\/tr><\/thead>
Usable capacity<\/td>Lower under deep cycling<\/td>Vysok\u00e1<\/td>High, depending on pack design<\/td><\/tr>
Daily cycling<\/td>Weak to moderate<\/td>Siln\u00fd<\/td>Strong potential<\/td><\/tr>
Partial charging<\/td>Sensitive to sulfation<\/td>Generally tolerant<\/td>Generally tolerant; no lead-sulfate mechanism<\/td><\/tr>
Startup current<\/td>Model-dependent<\/td>Strong if BMS allows<\/td>Strong if BMS allows<\/td><\/tr>
\u00dadr\u017eba<\/td>Higher for flooded types<\/td>N\u00edzk\u00e1<\/td>N\u00edzk\u00e1<\/td><\/tr>
Hmotnost<\/td>T\u011b\u017ek\u00e9<\/td>Sv\u011btlo<\/td>Usually lighter than lead-acid<\/td><\/tr><\/tbody><\/table><\/figure>

Sod\u00edkovo-iontov\u00e1 baterie<\/a><\/strong> has a real advantage over lead-acid in partial-charging solar applications because it does not suffer from lead-sulfate crystallization. However, it should not be described as zero aging. Like every rechargeable battery, sodium-ion packs still need BMS protection, temperature control, and datasheet-based validation.<\/p>

Engineering Checklist Before Selecting a 12V Sodium-Ion Battery<\/h2>

Use this as an inquiry checklist before asking a supplier for battery sizing.<\/p>

Parametr<\/th>Minimum Input Needed<\/th>Pro\u010d na tom z\u00e1le\u017e\u00ed<\/th><\/tr><\/thead>
Water demand<\/td>Liters or gallons per day<\/td>Determines total work<\/td><\/tr>
TDH<\/td>Lift, pipe loss, pressure<\/td>Prevents energy under-sizing<\/td><\/tr>
Pump voltage<\/td>12V, 24V, or AC<\/td>Matches battery and controller<\/td><\/tr>
Running current<\/td>Rated or measured current<\/td>Defines continuous discharge<\/td><\/tr>
Startup current<\/td>Estimated or measured peak<\/td>Defines BMS peak requirement<\/td><\/tr>
Pumping schedule<\/td>Daytime, morning, night, cloudy backup<\/td>Determines battery Wh<\/td><\/tr>
Autonomy target<\/td>Number of backup days<\/td>Determines backup capacity<\/td><\/tr>
Teplota<\/td>Battery box min\/max temperature<\/td>Affects BMS and cycle life<\/td><\/tr>
Cable run<\/td>Length and gauge<\/td>Prevents voltage sag<\/td><\/tr>
Sk\u0159\u00ed\u0148<\/td>IP rating, ventilation, heat exposure<\/td>Affects reliability<\/td><\/tr><\/tbody><\/table><\/figure>

If you send these values to a battery supplier, they can size capacity, BMS current, enclosure, and charging strategy much more accurately.<\/p>

Complete Example Summary<\/h2>
Design Item<\/th>Hodnota<\/th><\/tr><\/thead>
Daily water volume<\/td>10,000L<\/td><\/tr>
TDH<\/td>30m<\/td><\/tr>
Pump efficiency<\/td>60%<\/td><\/tr>
Full daily energy demand<\/td>1,362Wh<\/td><\/tr>
Battery-supported share<\/td>20%<\/td><\/tr>
Required battery energy<\/td>272Wh<\/td><\/tr>
Usable battery energy<\/td>22.7Ah<\/td><\/tr>
Sodium-ion DoD assumption<\/td>90%, verify by datasheet<\/td><\/tr>
Minimum nominal capacity<\/td>25.2Ah<\/td><\/tr>
Practical one-day selection<\/td>12V 30Ah<\/td><\/tr>
Practical cloudy-day selection<\/td>Around 12V 100Ah<\/td><\/tr>
Pump running current example<\/td>10A<\/td><\/tr>
Recommended peak discharge<\/td>30A\u201350A minimum<\/td><\/tr><\/tbody><\/table><\/figure>

This is not a universal battery size. It is a sizing method. If TDH, pipe length, outlet pressure, off-sun pumping time, startup current, or autonomy requirement increases, the required battery size also increases.<\/p>

Z\u00e1v\u011br<\/h2>

A reliable solar irrigation pump battery is not selected by amp-hours alone, but by matching water demand, TDH, pump efficiency, startup current, usable DoD, autonomy days, wiring loss, and field conditions. A 12V sodium-ion battery can be a strong option for remote agricultural pumping when the pack is matched to the real system\u2014not chosen by chemistry claims alone.\u00a0Kontaktujte n\u00e1s<\/a> to design the right sod\u00edkovo-iontov\u00e1 baterie<\/a> pack for your remote solar irrigation pump.<\/strong><\/p>

\u010cASTO KLADEN\u00c9 DOTAZY<\/h2>

How do I calculate the battery size for a 12V solar irrigation pump?<\/h3>

Calculate required watt-hours from daily water volume, TDH, and pump efficiency. Then decide how much pumping must come from the battery instead of direct solar power. Convert Wh to Ah by dividing by 12V, adjust for usable DoD, and multiply by autonomy days if cloudy backup is required.<\/p>

Can a 12V sodium-ion battery handle pump startup current?<\/h3>

Yes, if the pack is designed with a suitable BMS and cell discharge rating. For many small DC pump systems, the battery peak discharge rating should be at least 3\u00d7 to 5\u00d7 the pump\u2019s continuous running current.<\/p>

Do I still need a water tank if I use a larger battery?<\/h3>

Usually, yes. In agricultural pumping, stored water is often cheaper and more reliable than oversized battery capacity. A strong design uses solar panels to pump during the day, a tank to store water, and the battery to cover early morning, evening, cloudy, or backup operation.<\/p>

What information should I send to a battery supplier for accurate sizing?<\/h3>

Send daily water volume, TDH, pump voltage, running current, startup current, pumping schedule, autonomy-day requirement, local temperature range, cable length, enclosure conditions, and whether the system uses direct DC pumping or an inverter.<\/p>","protected":false},"excerpt":{"rendered":"

Sizing a battery for a remote solar irrigation pump is not just an amp-hour calculation. A reliable system must store enough usable energy, start the pump without BMS shutdown, and keep water moving when sunlight is weak or maintenance access is limited. Many off-grid pump failures happen because the battery is selected only by Ah….<\/p>","protected":false},"author":1,"featured_media":1180,"comment_status":"closed","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"rank_math_lock_modified_date":false,"_kad_post_transparent":"","_kad_post_title":"","_kad_post_layout":"","_kad_post_sidebar_id":"","_kad_post_content_style":"","_kad_post_vertical_padding":"","_kad_post_feature":"","_kad_post_feature_position":"","_kad_post_header":false,"_kad_post_footer":false,"footnotes":""},"categories":[19,26],"tags":[],"class_list":["post-5158","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-news_catalog","category-product-news"],"_links":{"self":[{"href":"https:\/\/www.kmdpower.com\/cs\/wp-json\/wp\/v2\/posts\/5158","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.kmdpower.com\/cs\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.kmdpower.com\/cs\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.kmdpower.com\/cs\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/www.kmdpower.com\/cs\/wp-json\/wp\/v2\/comments?post=5158"}],"version-history":[{"count":1,"href":"https:\/\/www.kmdpower.com\/cs\/wp-json\/wp\/v2\/posts\/5158\/revisions"}],"predecessor-version":[{"id":5159,"href":"https:\/\/www.kmdpower.com\/cs\/wp-json\/wp\/v2\/posts\/5158\/revisions\/5159"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/www.kmdpower.com\/cs\/wp-json\/wp\/v2\/media\/1180"}],"wp:attachment":[{"href":"https:\/\/www.kmdpower.com\/cs\/wp-json\/wp\/v2\/media?parent=5158"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.kmdpower.com\/cs\/wp-json\/wp\/v2\/categories?post=5158"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.kmdpower.com\/cs\/wp-json\/wp\/v2\/tags?post=5158"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}