With all of the obtainable battery fashions and types in the marketplace, discovering an acceptable trolling motor battery usually generally is a daunting process, nevertheless it should not be.

However earlier than getting a brand new battery or battery pack, one ought to first write down a number of issues, together with the dimensions and weight of the boat, motor energy, required trolling time, and naturally, the funds allotted for the brand new trolling motor battery.

Up to date: October 29, 2021.

On This Web page:

Dimension and Weight of the Boat

Electrical Trolling Motor Thrust vs. Energy

What Sort of Battery Do I Want For My Trolling Motor?

Little Little bit of Math

BCI Group 31 Batteries

100Ah Lithium Batteries

200Ah Lithium Batteries

Often Requested Query – FAQ

Few Remaining Phrases

Dimension and Weight of the Boat

Electrical motor energy is rated in “kilos of thrust” (or “kg of thrust”) which isn’t essentially the most right measure of power, nevertheless it offers a tough image of the electrical motor’s capacity to offer technique of propulsion for the boat.

Additionally, when choosing the proper electrical trolling motor, it’s a good suggestion to over-dimension each the electrical motor and the battery for security causes.

The next desk lists the most typical sizes and weights of small boats and pontoons generally used for trolling:

Boat Weight Boat Size Minimal Suggest Thrust Beneficial Thrust With Energy Reserve 2000 lbs (906 kg) <16 toes(~4.9 m) 40 lbs~18 kg 60 lbs~27 kg 2500 lbs (1132 kg) ~17 toes(~5.2 m) 50 lbs~23 kg 70 lbs~32 kg 3000 lbs (1360 kg) ~18 toes(~5.5 m) 60 lbs~27 kg 80 lbs~36 kg 3500 lbs (1586 kg) ~19 toes(~5.8 m) 70 lbs~32 kg 90 lbs~41 kg 4000 lbs (1812 kg) ~20 toes(~6.1 m) 80 lbs~36 kg 100 lbs~45 kg 5000 lbs (2265 kg) 21+ toes(6.4+ m) >100 lbs>45 kg >120 lbs>54 kg

Be aware that the precise required thrust relies on different issues too, for instance:

– water and climate circumstances: calm water and no wind require no further motor energy. However, robust currents and wind may also help the vessel sail sooner down the present and wind, but when one has to sail up the present and wind, way more energy and bigger thrust are required.

– top of the boat: kayaks and many of the inflatable boats are low within the water with a comparatively modest space of the boat that may act because the sail, requiring little or no further energy. Nevertheless, some pontoon boats and catamarans/trimarans are very tall, requiring further energy and thrust in windy circumstances.

– presence of seagrass or comparable vegetation: subsurface vegetation will increase the vessel’s resistance requiring extra energy and thrust to maintain the required trolling velocity. Additionally, the vegetation can wrap across the propeller shaft, significantly growing the motor load and even inflicting the circuit breaker to go off.

So, be happy to decide on the required electrical trolling motor energy in accordance with the desk, simply keep in mind all (or most of) different doable conditions, too.

Electrical Trolling Motor Thrust vs. Energy

Thrust achieved by electrical trolling motor roughly equals to the water mass movement within the unit of time, multiplied by the water velocity distinction.

To be able to keep away from the mathematics as a lot as doable, simply keep in mind that an electrical trolling motor with a bigger thrust requires extra electrical energy.

The next desk lists among the widespread electrical trolling motors, their most thrust, nominal voltage, most present, and nominal most energy:

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To be able to maintain most currents at acceptable ranges (at most 50-60 Amps), stronger electrical trolling motors function at 24, 36, and even at 48 volts.

For instance, electrical trolling motors with thrust as much as 60-70 kilos function at 12 V, trolling motors with a thrust between 70-100 kilos function at 24 volts, whereas electrical trolling motors with thrust ranges of 100 or extra kilos, often function at 36 V, though there are fashions that function at 48 or much more volts.

In fact, there are exceptions. For instance, Minn Kota Riptide EM 160 operates at 24V with a most of 116 Amps. Nevertheless, it is a double motor electrical drive consisting of two 80 kilos electrical motors, requiring 58 Amps every – therefore the 116 Amps max.

What Sort of Battery Do I Want For My Trolling Motor?

When in search of a brand new trolling motor battery, be sure you verify battery chemistry, voltage, capability (Ah or Amp Hour Score), kind, Reserve Capability, most steady discharge present, most surge present, variety of charging/discharging cycles, and so on.

Trolling motor batteries should have the ability to face up to common deep discharge operations and cyclic use. Additionally, once in a while, these batteries are left unattended for weeks and even for months, with native temperatures being typically very low (winter) or extremely popular (summer season).

Frequent beginning/cranking automotive/boat batteries shouldn’t be discharged usually under 50% of their capability, or their working life might be considerably diminished.

Trending: Best Trolling Motor Battery Picks

Thus, for an electrical trolling motor battery, one ought to select a dual-purpose or ideally deep-cycle lead-acid or lithium marine or general-purpose battery. Such batteries have restricted cranking currents, however that isn’t what they’re designed for – they’ll simply face up to common deep discharges right down to 20-30% with out adversarial results on their working life.

Lead-Acid or Lithium Batteries?

Lead-acid batteries have been in use for a very long time and can proceed for use for numerous functions.

Lead-acid batteries could also be moist/flooded lead-acid batteries, Absorbent Glass Mat (AGM) Sealed Lead-Acid (SLA) batteries, or Gel-Cell SLA batteries.

Lead-acid batteries are reasonably inexpensive and dependable batteries that may be recharged utilizing numerous lead-acid battery chargers, preferable superior battery chargers that additionally embody battery diagnostics.

However, lead-acid batteries are heavy, they help a comparatively small variety of charging/discharging cycles, they do not tolerate effectively deep discharge purposes, they endure from capability loss when discharged by way of robust currents, and comparable.

Lithium rechargeable batteries initially value extra and are delicate to charging and discharging circumstances, however lithium batteries include the built-in Battery Administration Programs (BMS) that monitor the battery’s situation and if required, they shield the batteries from undesirable conditions like low/excessive temperature, low/excessive voltage, over-current, short-circuit, and comparable.

Additionally, as a way to lengthen the lithium battery working life, BMS often displays particular person cells and if required, it balances them.

Lithium rechargeable batteries come as beginning (with the ability to present enormous currents however for a restricted time) and as deep cycle batteries (having restricted most allowed currents, however nice capability). Additionally, some manufacturers provide dual-purpose lithium batteries that are in a position to present robust currents and which tolerates deep discharge circumstances effectively.

Lithium batteries value maybe 3-5x instances greater than lead-acid batteries, however they usually can face up to 5-10x extra charging and discharging cycles and are 3-4x lighter than lead-acid batteries. So, in the long term, they’re really cheaper (verify guarantee circumstances!) and save loads of weight.

Though there are a number of lithium battery chemistries in the marketplace at the moment, lithium deep-discharge rechargeable batteries which might be used as trolling motor batteries are nearly solely Lithium Iron Phosphate (LiFePO4) batteries, that includes a nominal voltage of three.2V per cell and are in a position to present ~1C present repeatedly and typically 2-5C currents for a really brief time period.

Lithium Iron Phosphate (LiFePO4) batteries are the most secure lithium battery chemistry, however in addition they will need to have protecting BMS – higher secure than sorry. Additionally, these batteries are true non-spillable and maintenance-free batteries, which might be in a position to function at any place.

Battery Voltage

Most batteries are supplied as 12V fashions, however there are lithium batteries which might be supplied as 12V, 24V, 36V, 48V, and so on. batteries.

Whereas lead-acid batteries could also be linked in sequence and parallel freely (some guidelines do apply!), lithium batteries could also be linked in sequence and parallel provided that explicitly allowed/advisable by the battery producer.

After selecting “one of the best” trolling motor, verify its voltage and most present.

Be aware: some electrical trolling motors function battery cost indicators which might be calibrated for lead-acid batteries – such battery cost indicators are inaccurate when the lithium batteries are used!

Battery Capability

Battery capability is given in Amp Hours (Ah) and is the flexibility of the battery to offer the present at sure circumstances.

Normally, the battery capability of the lead-acid batteries is given for the interval of 20h – the battery is discharged with 0.05C present.

When the battery is getting used for powering trolling motors, one should calculate discharge time when the trolling motor is pushed to its most as a way to discover the shortest time {that a} new, totally charged battery, is ready to energy such trolling motor.

When the discharge present of the lead-acid battery is elevated, the precise capability is decreased – when the lead-acid battery is discharged for one hour, the battery’s precise capability drops right down to 50-70% of the nominal capability!

Lithium batteries do not endure from such capability loss – many of the lithium batteries help 1C currents repeatedly for nearly an hour.

Variety of Charging/Discharging Cycles

When the deep-cycle lead-acid batteries are discharged right down to 80-100% DoD (Depth of Discharge), they help 150-300 charging/discharging cycles.

When the Lithium Iron Phosphate batteries are discharged right down to 80-100% DoD, they help as much as 2000-4000 charging/discharging cycles.

Additionally, Lithium Iron Phosphate batteries tolerate charging currents within the 0.33-1.0C vary and might be cycled a lot faster than lead-acid batteries.

Battery Weight

Relative battery weight might be simply calculated by dividing nominal vitality saved within the battery (often given within the Wh) by the load of the battery (given in kilos or kilograms).

The issue with that calculation is that for lead-acid batteries one makes use of nominal capability (rated for 20h fixed present discharge) and never the precise capability when the battery is used for powering trolling motor (or another comparable software).

When the lead-acid battery is discharged, for instance, for 90 minutes, the precise capability is simply 70-80% of the nominal capability, which will increase the battery’s relative weight much more.

However, lithium batteries tolerate very effectively discharge currents as much as 1C, with nearly no capability loss, inflicting the relative battery weight distinction between lead-acid and lithium batteries to be even bigger.

On common, a superb lead-acid deep-discharge battery is 3-6x heavier than the lithium deep-discharge battery – and that may be a lot.

Connecting the Batteries in Sequence and Parallel

In case your trolling motor operates at 12 V, you want one giant or a pair of two smaller batteries linked in parallel.

In case your motor operates at 24V, you want a pair of bigger batteries linked in sequence or 4 smaller batteries linked in parallel and sequence.

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In case your motor operates at 36V, you want three bigger batteries linked in sequence or six smaller batteries linked in parallel and sequence to realize desired performances.

To be able to maintain the variety of connections to the minimal, one may also go for 24V, 36V, or 48V lithium batteries – if the capability is just too low, go for the fashions that permit connecting the batteries in parallel and add sufficient batteries to create the battery pack in accordance with your individual wants and preferences.

In actual life, one not often makes use of an electrical trolling motor at full throttle on a regular basis – more often than not, energy is diminished right down to 30-50%, whereas the utmost energy is used solely in emergencies or when altering fishing places and comparable.

In the event you do use your trolling motor at full throttle more often than not, maybe it’s underpowered in your software, and getting a stronger motor (or yet another) with extra highly effective/bigger batteries will improve your security.

Little Little bit of Math

Sadly, as a way to decide one of the best trolling motor battery, some math is required.

Lead-acid batteries are often called being very tolerant when working linked in sequence (for bigger voltage) and in parallel (for bigger capability). When connecting batteries in sequence and/or parallel, at all times attempt to acquire the identical batteries from the identical producer, ideally from the identical manufacturing batch.

Why? Properly, even the slightest variations among the many batteries may cause one battery to be underneath bigger stress/load, resulting in imbalances throughout the battery pack and in the end to the battery pack failure. And that may be pricey!

Instance: In the event you want/have an electrical trolling motor that pulls 55-60 Amp at most energy and also you need not less than 90 minutes of operation at full throttle, you want not less than 150-160 Ah battery.

60 A x 1.5 h = 90 Ah

Since we do not wish to totally discharge the lead-acid battery, we are going to discharge it down to twenty%:

90 Ah / 0.8 = 112 Ah

The nominal capability of lead-acid batteries drops when they’re being discharged sooner. On common, when such batteries are discharged inside a 1.5 h interval, their capability drops right down to ~70-80% of nominal capability. Simply to be secure, let’s assume that our battery capability drops right down to 70% of nominal capability when being drained at such charge:

112 Ah / 0.7 = 160 Ah112 Ah / 0.8 = 140 Ah

Though that is the calculation for the ‘worst-case state of affairs’, it is usually a calculation for the real-life state of affairs!

In the event you do not want to join the batteries in parallel as a way to obtain desired capability, good decisions for such necessities are batteries of the BCI Group 8D, with capacities of 200 or much more Ah.

Nevertheless, when you do not thoughts connecting batteries in parallel, the listing of potential batteries is for much longer (you simply want a pair of them) – virtually a pair of any deep cycle batteries with not less than 75-80 Ah shall be sufficient.

BCI Group 31 Batteries

BCI Group 31 batteries are a extremely popular battery group measurement utilized in many automotive, marine, off-the-grid, and industrial purposes.

Group 31 batteries are available numerous chemistries together with lead-acid moist/flooded, AGM, Gel-cell, enhanced moist, lithium, and so on.

One of the best trolling motor group 31 batteries function 12V nominal voltage and nominal capability of 100-135 Ah, with some fashions that includes Reserve Capability of as much as 240+ minutes, particularly the lithium 100Ah 12V batteries.

The next comparability chart lists among the hottest group 31 batteries, with their most vital options and specs:

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For infrequent use of an electrical trolling motor, one ought to go for an inexpensive, general-purpose, deep-cycle, sealed lead-acid battery (AGM or Gel-Cell) with a nominal capability of 100+ Ah.

Such batteries are simple to take care of, they tolerate vibrations very effectively, have good capability when discharged with currents as much as 0.5C.

For frequent use, however with prices in thoughts, one ought to go for a powerful and sturdy AGM or Gel-Cell battery that tolerates biking purposes reasonably effectively, like Odyssey, NorthStar, Optima, and VMAXTANKS batteries.

Nevertheless, even such batteries can’t be in contrast with the Group 31 lithium batteries by way of light-weight design and variety of charging/discharging cycles – and sure, these batteries value extra, however in the long term, lithium batteries get monetary savings!

100Ah Lithium Batteries

100Ah lithium batteries are a extremely popular class of deep-cycle lithium batteries ranging in voltage from 12V to 48V.

Though these batteries have restricted most discharge currents to principally 1C (100 Amps), that is nonetheless robust sufficient for many trolling motors in the marketplace (max. present as much as 60 Amps).

The next comparability chart lists among the hottest 100Ah lithium batteries, with their most vital options and specs:

Most 12V 100Ah lithium batteries belong to the BCI group 31, though the batteries with larger voltages are typically 4D (6D) batteries.

Be aware: Many batteries are labeled as 4D batteries, however they really have dimensions nearer to BCI 6D battery group.

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100Ah deep-cycle lithium batteries can’t be used as beginning/cranking batteries, however that isn’t their meant use – they’re designed for purposes that require currents as much as 1C, from the light-weight batteries that help a lot of charging/discharging cycles.

When connecting lithium batteries in parallel and/or sequence, at all times join them as advisable by their producer.

And if You might be in search of lithium batteries of even bigger capability, verify 200Ah lithium batteries.

200Ah Lithium Batteries

200Ah lithium batteries are made as 4D (6D) and even bigger batteries, ranging in voltage from 12V to 48V.

The next comparability chart lists among the hottest 200Ah lithium batteries, with their most vital options and specs:

The usage of such giant batteries reduces the variety of connections between the batteries, simplifying their use.

For instance, Ampere Time 12V 200Ah Plus (Amazon hyperlink, hyperlink opens within the new window) battery weighs solely 52.3 kilos (23.7 kg), can present 200 Amps repeatedly, 400 Amps for five seconds, and helps connecting in parallel/sequence (as much as 4).

Single such battery is ready to energy 12V 50 Amps electrical trolling motor for ~4 hours at full throttle (if it does not overheat within the meantime), or 6+ hours when the motor is throttled right down to ~33 Amps.

Often Requested Query – FAQ

These are the most typical questions on electrical trolling motors and their batteries. A few of them might be answered with a easy sure or no, however a few of them require way more elaborate solutions.

How lengthy will a 100ah battery run a trolling motor?

This relies on the precise battery capability and the precise trolling motor present draw.

Lead-acid batteries discharged inside one hour function precise capability within the 55-70% nominal capability vary – for instance, 12V 75Ah AGM battery might present 40-50 Amps for one hour. If You might have an electrical trolling motor that pulls 50 Amps max. and You propose to make use of it at most throttle, You possibly can anticipate such battery to last as long as 45-50 minutes (60 minutes at most, if a high-quality battery is used) underneath such circumstances.

One of the best plan of action is to verify the battery’s precise fixed present discharge desk and evaluate it with the deliberate electrical motor use/present draw.

Can you employ a lithium battery for a trolling motor?

Sure, You possibly can. However, lead-acid batteries function a nominal voltage of 12V with precise voltage starting from 12.8-13.2V right down to 10.5 and even fewer volts. However, lithium batteries function a nominal voltage of 12.8 volts which may be very fixed throughout the discharge.

If the trolling motor contains a battery cost indicator, it’s most likely calibrated for lead-acid batteries and it may possibly present inaccurate readings for lithium batteries.

The best way to cost trolling motor battery?

Simply – join the battery to the acceptable battery charger and let it do its job.

Moist/flooded, AGM and Gel-Cell batteries must be charged utilizing currents within the 0.1-0.2C vary (mannequin dependent) utilizing good/superior lead-acid battery chargers that permit the person to set the battery kind (moist, AGM, Gel) and that function temperature sensor for temperature compensation.

Lithium batteries must be charged utilizing chargers for lithium batteries (or not less than with the chargers that function lithium battery charging mode) utilizing currents within the 0.2-1.0C vary (mannequin dependent).

Does a 24-volt trolling motor want 2 batteries?

A 24-volt electrical trolling motor requires a single 24-volt battery or 24-volt battery pack consisting of two 12V batteries linked in sequence.

Will a automotive battery work for a trolling motor?

Sure, it’ll. However, if such battery is discharged too low, it will be unable to crank the automotive’s engine till it’s totally recharged once more.

Additionally, automotive batteries are beginning batteries, which aren’t meant for deep-discharge purposes – if You wish to check the electrical trolling motor utilizing a automotive’s battery, go for it for a couple of minutes.

For instance, if 50 Amps trolling motor is run for five minutes utilizing a 12V beginning battery, the battery shall be discharged by ~4.2 Ah – that’s lower than 10% capability for a 42Ah battery.

Will a automotive battery harm a trolling motor?

No, the automotive battery won’t harm your trolling motor, however your trolling motor might hurt your automotive’s battery which is beginning battery and never a deep-cycle battery.

How lengthy can a automotive battery run a trolling motor?

This relies on the battery capability and common trolling motor present.

For instance, a 12V 50 Amps electrical trolling motor discharges the 12V battery by ~0.84 Ah per minute. If You might have a superb 12V 75Ah lead-acid battery that is ready to present 50 Amps for 1h (precise 1h capability is 50Ah!), powering the electrical trolling motor for half-hour will discharge such battery right down to 50% DoD (50% SoC) – such battery continues to be in a position to crank petrol and even diesel engines, however not so good as when the battery was totally charged.

Are lithium batteries price it for trolling motors?

When lithium batteries are cycled usually, sure, they’re effectively price it.

Additionally, for purposes the place the light-weight battery is a “must-have”, lithium batteries have to be used, no matter how usually they cycle!

Few Remaining Phrases

When selecting “one of the best” battery for an electrical motor, go for the mannequin or fashions that finest fit your wants and preferences.

For a really small electrical trolling motor (<30 kilos, <30 Amps), one might go for lighter and smaller AGM/Gel-Cell batteries which might be additionally cheaper – simply bear in mind that lead-acid batteries lose their capability when discharged utilizing robust currents.

Lithium batteries have to be recharged utilizing devoted lithium battery chargers or not less than with superior AGM battery chargers with the devoted lithium battery charging mode, however they provide massive weight financial savings and help a lot bigger variety of charging/discharging cycles that they get monetary savings in the long term.

Most capability/ saved vitality and the utmost energy of electrical trolling motor also needs to function some “reserve” for emergencies (robust present, dangerous climate, and so on.) – it does add some further weight and extra prices, nevertheless it additionally will increase security.

Once more, no matter You do, keep secure!