View Transcript

Hide Transcript

Transcript is auto-generated.

   we've got a question from a fellow boater   steve   steve asked jeff what are the   limitations of running   a large   load   on a battery bank that is   seriously discharged   and that's a great question there are   limitations especially if this battery   bank is a lead acid battery either   flooded or agm   the reality is that as battery banks   discharge over time   and this could be from your own use   let's say for example   you're at  of capacity   or even  of capacity   at once you're at  of capacity and you   start adding a large load and that large   load might be for example running an   inverter   which is powering a microwave or an   induction stovetop   and the loads   for that inverter are significant as a   proportion of your battery bank size   meaning your battery bank size isn't   extremely huge it's reasonable you're   already at  of capacity and now   suddenly you're putting on a large   dc load like you could easily put a     amp load on a battery bank   uh running an inverter absolutely that's   not   it's totally it happens now when you do   that the battery bank the voltage is   going to sag   and the voltage might sag and you might   have started the load and you know the   battery voltage prior to you starting   the inverter was      it might have been  .   and now you run a large   amp dc load   on your battery bank well what's going   to happen is and this is what steve's   noticing is you're going to see the   voltage drop maybe even the  - four   ten two and it might even trigger the   inverters stop working because you might   have a low voltage disconnect   switch that's you know sort of a setting   on your inverter charger to actually   stop the inverter from working if it   reaches a set point voltage of let's say   and generally that's configurable it's   like  . volts   so   it's tricky and it's a limitation of   batteries is as the batteries tire like   us humans you can't expect yourself   after a  hour work day to have as many   as much energy or oomph as you did on   your first hour of your work day   you're the same person but your  th   hour of work of physical labor let's say   is not going to be the same as your   first hour of physical labor   and batteries are the same over time and   this is for lead acid batteries because   over time they actually have less and   less capacity to give and they'll go   lower in lower voltages especially on   large dc loads that are applied to the   battery   now a way to offset that of course is um   to try to avoid using large ac dc loads   on a weak battery   or alternatively   if you're looking and this is something   that's really important to you   then you should maybe consider a lithium   battery bank because a lithium battery   bank is pretty much able to keep a   steady voltage regardless of depth of   discharge   now mostly of course eventually the   voltage will drop but it's going to stay   relatively steady for a long period of   time and that would be one of the   advantages of a lithium battery bank   is to have the batteries be able to   sustain large discharge amps   even when the battery is in a partial   state of discharge without affecting   the voltage to become too low to trigger   the inverter or alarms to be triggered   so it's a great question from steve and   it's something that we all have even on   my own boat you know i can't do   what i want when my batteries are  or     of capacity the reality is that my   inverter is not going to like to run   large   loads when my batteries are really weak   so sometimes you know i'll start the   engine again and   i'll start the engine   run a high output alternator to recharge   the batteries so that when i'm actually   using my battery bank at a low voltage   partially discharged i'm going to maybe   run the engine for     or  minutes   to try to give a little bit of oomph to   the battery bank so that the inverter   doesn't actually see a low voltage on   the battery bank so that's a great   question from steve and thanks for   asking and wishing you all the best so   if you're curious again go on our   website and find out more answers and   solutions with this sort of setup and   thanks for asking and thanks for all of   you for listening and tuning in