Having just returned from the Crick Boat Show, Britain’s biggest inland waterways festival, where we shared a stand with the Electric Boat Association, we thought that it might be a good time to talk about the electric boating market and how to choose the best battery.
Electric boating is currently enjoying a worldwide revival and electric boating for larger boats is now becoming a reality. From what started out as small day boats and launches, we now have fully sized canal and river boats being comfortably powered by electric propulsion.
It’s safe to say that demand for electric boats is growing rapidly, driven by an increasing consumer awareness of eco-friendly transportation options.
Range of options for battery technology
The demand for better propulsion technology for this new generation of hybrid and electric boats has led to a wide range of options for battery power – longer lasting, safer and more efficient than ever.
So what does the future hold for developments in battery technology for electric boating?
From small day boats to large canal craft, flooded traction cells have been used. These have been traditionally 6-volt 225Ah batteries (eight of them) with the most famous manufacturer being Trojan. These batteries power the majority of the golf cart and similar vehicle markets.
Larger flooded batteries would be from the industrial forklift truck market – 2-volt cells (24 of them) and in a variety of Ah, normally between 600Ah -> 1,000Ah.
The benefits of flooded traction batteries are simple – proven and cost-effective being the two key points. Somewhat less attractive is the need to top up with distilled water and vitally, a good ventilation system (whilst charging they produce explosive hydrogen gases).
More recently, the introduction of AGM or Gel batteries came onto the market, offering the same deep cycle ability but without maintenance and much safer, as gases are not produced under normal working conditions. Often these can be fitted in the living quarters, as long as there is adequate ventilation.
There is one other downside to both of the above and that is charging. Both types of batteries require regular full charges.
But what does this mean? Most lead acid batteries will absorb their charge readily up to 80%, but after that, the charge rate will slow down and the final stages of charging might take many hours.
Charging from an engine or generator will not always achieve this, unless for prolonged periods of time. Solar panels, however, can assist. The main solution is an overnight mains charge.
Combatting the impact of PSOC
Poor charging results in a condition called sulphation. This is a growth on the plates, making you lose capacity (AH). This can slowly get worse and is one of the biggest premature failures of lead acid batteries – known as Partial State of Charge (PSOC).
So now we have the introduction of Lead Carbon batteries – these batteries have been developed for, and from the renewable energy sector. These batteries significantly reduce the effects of PSOC.
Lead Carbon Gel batteries combine Carbon and Graphene to the negative plates, offering the best from Lead Acid batteries and capacitors. This allows the battery to not only recharge more efficiently and quicker, but significantly prolongs battery life and at the same time, increasing the number of cycles (discharge and recharge).
Introducing the third alternative – Lithium
Lithium batteries now offer the third alternative. This is what powers cars, as an example. They can be discharged more significantly than Lead Acid batteries, can recharge quicker – even in just two hours – will take up less space and weigh considerably less.
Safety has always been a concern for many, but the latest Battery Management Systems virtually eliminate any danger with a variety of protections, simply shutting off the battery.
Downsides are notably cost and in severe cold weather, they can’t be recharged unless the storage area is warmed, or the batteries themselves are fitted with heating elements.
The latest designs include using 48v100Ah batteries in racks (so add as many as you need to make the AH) or use 12v connected in series and then parallel.
Help with choosing the best electric boat battery
So, to facilitate this electric boating revolution, boat owners and manufacturers now have a wider choice of power solutions than ever. If you still have questions about the propulsion options for your electric boat, get in touch with our battery specialists here at DC Battery Technologies.