Eelex 8000 all electric boat

8 tips on how to charge an electric boat

April 13 2021

8 tips on how to charge your boat batteries


Electric boat batteries can take anywhere from 1.5 to 36 hours to charge. The needed time to fully charge your system will directly depend on the number of banks (batteries) and the amps per bank the charger can output.

If you tend to feel lost in the jumble of electrical lingo, don’t worry we’re here to unravel it and also give you some useful recommendations to extend your battery life and optimize its use.



Battery stage charging:


To be able to know when and how to charge your batteries the correct way, you must first be familiar with the stages that take place when you plug your battery bank to recharge.


Stage 1: Bulk.
When you plug in your charger, the maximum charge voltage and current output are applied to restore your battery power. Usually until it reaches up to 80% of the battery’s capacity.


Stage 2: Absorption.
It happens when the battery is between 80% and 90-95% of its capacity, where a constant charge voltage is applied but the charging current declines.


Stage 3: Maintenance.
During this phase the batteries reach 100% of their capacity with a lower voltage and current applied.


The choice of battery charger comes into play since using a charger that outputs the same voltage and current at all times, without considering these phases, can severely damage your batteries if they are significantly overcharged.

We use Juice Booster as our charger of choice, which is CE-compliant and meets all the requirements of the standards applicable worldwide. The Juice Booster station controls the voltage and current that the battery gets throughout the charging cycle, to ensure a fast, safe and precise charge.

It also provides hassle-free charging worldwide, with intelligent current control thanks to automatic adapter recognition. It eliminates the need for tiresome calculations or manual current adjustments, although it can still be adjusted manually if desired. This means you just need to plug & charge with no further adjustments needed.


Durable, reliable & water resistant you can always check how much is left until full charge.



Speaking about charging times, these are affected directly by 2 factors: the number/types of batteries that need to be charged, and the number of amps-per-bank that the charger can output. So in other words, the higher the amperage the charger offers the more rapid charging times it will achieve.




We use dual 60 kWh lithium-ion batteries in the Eelex 8000 - 2021 Edition, giving you a total of 120 kWh of storage. This, together with the up to 32 amps per bank that Juice Booster provides gives you the following charging times:


Charging 20-80%

- 3-Phase 32A: 3H

- 3-Phase 16A: 6H

- 1-Phase 16A: 17,5H


Charging 0-100%

- 3-Phase 32A: 6H

- 3-Phase 16A: 12H

- 1-Phase 16A: 36H



Tips for maintaining your electric boat batteries.


Having proper battery maintenance by following these recommendations will help you preserve the longevity of your batteries:


1) Charge your battery after every use and allow it to receive a full charge.

2) Never over or under charge your batteries – By doing so, their overall life can be reduced. A multi-stage charger (like Juice Booster, our charger of choice) is a must.

3) Always use recommended voltage requirements and unplug immediately when the charge has been completed.

4) Don't push your battery to low depths of discharge. This means that a battery that is usually re-charged when it reaches 30% of its capacity will last longer than a battery that is pushed to 10% or less of it’s capacity on a regular basis which in consequence will have a shorter lifespan.

5) Check temperature when charging – Temperature directly affects the voltage needed to charge a battery. In cold climates, you will require more charging volts per cell to reach a full battery charge than warm in areas. Having a charger with automatic temperature compensation will guarantee the most efficient charging regardless of the climate you have.

6) Avoid battery storage in extreme temperatures (hot or cold) – If you seasonally store your boat, it’s highly suggested to avoid leaving the batteries in. It’s better to store them safely in a place without extremely hot or cold temperatures, especially over long periods of time.

7) Avoid storing batteries uncharged. We suggest giving them a full charge before storing them for the season or a long stretch.

8) Keep your battery terminals clean.



Battery maintenance of an electric boat is easier and also cheaper than maintaining a combustion engine. Gone are the days of oil changes or winterizing the motor after each season. Following these simple recommendations for battery charging and maintenance you will enjoy the most clean, silent and sustainable boating experience possible.

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