Winter storage of lithium batteries
Tips and tricks for winter storage of lithium battery
Preparing for winter storage of lithium batteries in boats and motorhomes
Published Friday 27.10.2023 - Written by: Johan Fr. Bruenech
Using lithium batteries in winter
Makspower lithium batteries can be used down to minus 20 C.
If you're coming on board in winter, just turn on the heater, lights and radio.
Everything works as it should.
The capacity of lithium batteries decreases when it's cold, but there's still plenty left.
Self-discharge in lithium batteries
Makspower lithium batteries have very low self-discharge. Expect up to 3% per month. During a long winter, five or six months, you can expect about 18% of capacity to disappear. This means nothing for the batteries. You still have most of it left when spring comes.
Should the lithium batteries be fully charged before winter?
There are slightly different theories about whether lithium batteries should be fully charged before being stored for the winter. Considering that many boats and probably motorhomes are connected to shore power all year round, we have no hesitation in recommending that lithium batteries are fully charged before storage.
Charging lithium batteries in the cold
If your boat or motorhome is connected to shore power, the batteries are practically full all the time.
Then there is no charging either. If the shore power goes out, the charger will later restart and charge.
Makspower lithium batteries can be charged with up to 5 amps per 100 Ah battery down to minus 10°C.
If you have 300 Ah lithium batteries, you can charge at up to 15 amps. If you have a more powerful charger, you should not charge.
Then you might as well unplug the charger.
Boat moored in a bubble port, how do I handle lithium batteries in winter?
If the boat is in a bubble harbor, the boat and batteries are less exposed to the cold. The batteries are usually placed under the floorboards, under bunks or other places that receive a little heat from the seawater. The batteries are therefore kept at around 0 degrees. You can then use the batteries as normal.
Should I turn off the main switch to the consumer bank in winter?
To ensure that there is no current draw during the storage period of the lithium batteries (lead-acid batteries as well), you must disconnect the negative cable to the consumer batteries.
Why would I do that? I have a main switch that can turn off the power?
It is quite common that despite the main switch being turned off, something is still on. This could be the boat's panel with display on the tank, voltage, AIS and battery monitor.
The battery monitor also draws power
Even though a battery monitor draws little power, you're talking about a lot of hours over six months.
5 months is the same as 3600 hours. If the battery monitor draws 0.1 amps, 2.4 Ah per day equals 360 Ah over 5 months.
There's so little current draw that you won't even notice it when you're using your boat or motorhome. Over time, that can quickly mean flat batteries.
Are lithium batteries damaged if they are completely discharged?
Over the past ten years, we have seen many Makspower lithium batteries that have been fully discharged. So far, we have not seen any batteries break down. We recommend recharging the battery as soon as possible.
Makspower lithium batteries have a huge advantage over lead batteries because they can withstand full discharge without being damaged. If the lithium batteries are left empty, it will reduce the service life. But so far we have not seen any batteries damaged.
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