A hybrid lead-lithium installation
Since the arrival of lithium batteries on the boating market, more and more boaters are equipping their boats with these new technologies. But most of them are forced to keep two separate installations between their lead-acid and lithium batteries or to replace them completely.
The German manufacturer BOS offers an alternative with a lead-lithium hybrid solution. The LE300 modules from BOS, of the LiFePo4 type, are connected in parallel to the existing AGM or Gel lead battery. With a modular design, their capacity can be adapted to the needs and capacities of the ship.
The best of lithium and lead
The equipment manufacturer summarizes its solution as "the best of both worlds".
The boater benefits from the price advantages of lead and its discharge and peak current capacity. As the batteries are usually already present in the case of a retrofit, he saves on the number of new kW to buy.
At the same time, it is taking advantage of the benefits of lithium to increase its fleet with light, compact and long-lasting batteries.
To optimize the price/performance ratio, BOS recommends a ratio of 1/3 lithium to lead capacity, but it is possible to go beyond this. By adding 24 LE300 modules, the lithium capacity reaches 600 Ah.
Intelligent management of the boat's energy
The BOS installation manages the hybridization of fleets in all situations.
For the current calls lower than 12.5 A, corresponding to the usual daily consumption, only the LE300 modules are solicited.
In case of a peak load such as starting the boat's engine or using a windlass, requiring a higher current, the lead park provides the additional current higher than 12.5 A.
Once the peak is over, the LE300 modules are discharged in the lead park to bring back its voltage around 13 V if necessary.
Thanks to this BMS management, the LE 300 modules ensure that the lead batteries are kept charged, thus extending their life. This feature is particularly interesting when wintering or on a boat with a solar panel.
To maximize the performance of the recharge, lead-acid batteries are charged first. This avoids sulphation of the batteries and their premature aging. Once a constant voltage is reached and the current decreases, the BMS detects the phenomenon and recharges the lithium battery with the remaining available energy, until the capacities of both batteries are completed. The charge profile of each battery is thus optimized.
For better redundancy and performance, the LE300 modules each have their own BMS and each cell has an integrated heater.
Easy to integrate on board
Beyond its electrical capabilities, the LE300 module is also easy to install, in refit as well as in new construction. It is entirely Plug&Play. The installation is done in 10 minutes and its compactness allows to find easily a place on the boat. It doesn't need to review the electrical peripherals, kept on board like chargers or inverters.
BOS is distributed in France by Kent Marine.
