Solar Battery Charger question ..

[LAKERtoo]

.. am I right in thinking that a small, inexpensive solar panel can just be plugged into the 12 volt outlet of my R21 Classic to maintain a battery charge ? .. if not, whats the simplest system that just sits in the window or the engine box .. there's nothing much in the way of consumption but the bilge pump .. Thanks for any comments .. Rob

 

[Pilotnavigator]

Bilge pumps take a fair amount of current. If it rums only once a week or so you are ok, else there may be issues. Even a small 5watt charger can harm batteries if left on for weeks. It will give you at best a half amp hour charge. If you pop the breaker to make sure the always on devices like the vhf and radio that take a bit of current durning sleep mode are all off, you should be good.

 

[ixlr8]

You really should put a charge controller between the solar panel and the battery's. Even a small solar panel directly connected to a battery can ruin that battery by overcharging it.

 

[MooniesBBQ]

Look at Morningstar sg-4 sunguard pwm charge controllers. I've got a 15watt panel and controller on my generator battery at my cabin and it's always fresh and ready to go.

 

[LAKERtoo]

.. has anyone ever used these ? I've used their Genius battery charger/maintainer and they work well .. with the 12V plug in, would you leave battery switch on BOTH or ONE .. I'm interested in maintaining batteries with occasional rain thru September and bilge pump kicking in .. TIA .. Rob

NOCO XGrid XGS4AUTO 4W Portable Solar Panel and Auto Kit

by NOCO
Price:
CDN$ 82.92
Solar Charging Maintenance Kit; Keep your 12V automobile battery maintained through solar energy direct from the sun
Ultra-portable; Its compact, lightweight and foldable design makes it perfect for on-the-go;
Precision charging; Innovative 12V Flex Regulator charges and recovers 12V batteries for optimal maintenance
Designed for safety; The safest solar charging solution with reverse polarity, spark-proof, overcharge, over-current and short-circuit protection
Modular Design; Plug-n-play technology with all XGrid products for charging 6V, 12V and USB devices

 

[Pilotnavigator]

4 watts will provide less than 1/2 amp per hour charging on a bright sunny day. You expect to need it to keep your batteries charged when the bilge pump is needed. The rainy days are not the sunniest days. I don't have the specs on the bilge pump but i suspect it takes about 2 amps of power. You may expect it to run for 30 minutes on a real rainy day. It would take the solar panel two hours to make up the difference on a sunny day. So it should all work out fine. You can do your own calculations with actual pump and expected run times and see how comfortable you are with them.

 

[LAKERtoo]

.. so the unit still charges battery with the battery select switch turned off and would it be just the house battery that rec'd the charge ? Thx

 

[Pilotnavigator]

My solar panel charge controlle is connected directly to the house batteries. I have added two more house batteries, and moved the bilge pump to the house side. I suppose the battery combiner would kick in when needed.