Date:         Fri, 1 May 2020 04:09:09 -0500
Reply-To:     Bill Berg <overthehillbill@GMAIL.COM>
Sender:       Vanagon Mailing List <vanagon@gerry.vanagon.com>
From:         Bill Berg <overthehillbill@GMAIL.COM>
Subject:      Charging Lithium Battery with Redarc
Content-Type: text/plain; charset="UTF-8"

This is the info the Redarc technician sent from down under :  " The
BCDC1240D will require no additional relay in order to charge via solar and
the vehicle inputs, however if you were to charge the vehicle battery from
shore power with a 6A charger, the BCDC will indeed try to charge the
auxiliary Lithium. This can present as a problem as the BCDC will attempt
to draw any current required to charge the Lithium battery – this very
quickly overcomes the 6A charger output and the vehicle battery voltage
drops below 12.7V again, causing the BCDC to stop charging. This cycling is
not ideal for longevity of all chargers involved, and may even cause the 6A
charger to log an error as the output voltage fluctuates.

The Solar input will only be charging the Lithium battery, so when in
storage if you are able to make this input available, it will not require
any more charge from another source – you can then isolate the BCDC from
the vehicle battery through a manual isolation switch or similar, and
charge the vehicle battery with your 6A charger unhindered.The BCDC1240D
will require no additional relay in order to charge via solar and the
vehicle inputs, however if you were to charge the vehicle battery from
shore power with a 6A charger, the BCDC will indeed try to charge the
auxiliary Lithium. This can present as a problem as the BCDC will attempt
to draw any current required to charge the Lithium battery – this very
quickly overcomes the 6A charger output and the vehicle battery voltage
drops below 12.7V again, causing the BCDC to stop charging. This cycling is
not ideal for longevity of all chargers involved, and may even cause the 6A
charger to log an error as the output voltage fluctuate. Hi Bill,



As the BCDC1240D is capable of drawing approximately 45A from the vehicle
input when required, a shore power charger that was capable of supplying
close to this current or more would be beneficial if used whilst everything
connected.

The more simple method is definitely to use the solar for the auxiliary
battery through the BCDC1240D and isolate the two batteries!



Best regards,

Kahlan Cester " ......  .Well I don't intend to get a 45 amp charger and
already had a battery cutoff switch on order , so as these times we live in
now are ideal for projects I figure it's time to complete some wiring on
the shop I built 16 years ago , where the Westy sits in storage all winter
due to the tons of salt used in these parts. So run AC I never
finished running to mid shop along with a line running to south wall for
mid size solar panel to let the Redarc do it's thing and have a place to
plug AC into Westy for onboard small smart charger for start battery panel
to charge. Got all that material for less than a big smart charger and
another entertaining project to boot, yay !