Thread: how to charge the caravan batteries

Originally Posted by drivesafe

Being as you plan on doing regular day trips, if you had a dual battery setup you could use your tow vehicle’s batteries to top up your house batteries via an inverter and a battery charger and probably not need additional solar.

Ooo, Id never thought of being able to do it that way round.

Hi Gullible, this type of setup is only good if you do some daily driving and while it can top up or even recharge the house batteries, it is something that only needs to be used if your existing solar setup is not keeping pace with your usage.

Even if you do a daily drive trip every day, you might find you only need to use this setup to top up your house batteries once every three or four days.

The advantage of using an inverter/battery charger setup is that while you are topping up or charging the house batteries, your tow vehicle batteries do not have to be fully charged to be able to fully charge the house batteries.

The setup is also easy to do. Just fit an Anderson plug to say a 300w inverter and the run an ordinary 240VAC extension cord over to a 10 amp battery charger in your van.

Job done.

The smaller the load placed on a lead acid battery, the greater the amount of energy you can get from that battery and at the other end, the slower you charge a lead acid battery, the more efficient the charge is so you need less energy to fully charge the batteries.

So even though there is a loss through the inverter/battery charger setup, by using a small inverter and battery charger, you increase the efficiency of this type of setup.

On the flip side, if your solar is keeping up with your daily power usage, you can always use it to top up your tow vehicle batteries, keeping them in a higher state of charge just incase you get some bad weather days.

This type of setup gives you a win, win, win system.

I use this setup to charge deep cell battery in a camper trailer. The second battery in the vehicle (charged by Drivesafe's magic SCR80) feeds the inverter, but the inverter and (5 step 7 amp ) charger are housed together in an (electrically) insulated vented enclosure (to dissipate heat) (12V in; 12V out) in the camper. This minimises potential risk of 240V electrocution in case of accidents... I see some 4WDs are now offering 240V outlet as a built in option in the vehicle... bit of a worry? I am still edgy with the thought of a 26kg battery breaking loose in the rear of the P38 so need to think of a better way to restrain it... must be an age thing

We have two x 135w Kyocera panels permanently fitted to the roof of our van and two x 100 amp AGM battery's in the van. A real bonus from it is that we do not need to carry a genie any longer and while we can charge the van battery's from the vehicle we never have had to since the solar was fitted. So since fitting solar we have never had power problems mind you we don't have a fixed compressor fridge we have a 3-way, but we do have a 60L chest fridge that we always use when camping. To say we are power hogs would be an understatement as we use fans, TV, stereo etc in the day time as well as night plus lots of lights etc plus we normally plug in at least one other chest fridge each day while camping with friends as they don't have adequate solar to charge their battery's up and run their fridge and they get sick of running the genie every bloody day.

If you had a large (over 150L) compressor fridge then to do it properly you would need over 400w of panels and a couple of decent sized house battery's at least.

We don't tend to drive very much while camping so wouldn't be interested in trying to charge battery's up everyday and then go back and charge up the house battery's, seems like hard work and means you have to drive every day to keep your battery's even 3/4 charged. The way we have it set up you don't even think about it, the solar just charges the battery's up to float level usually by 9:00 am most mornings in summer. Then we can use power all day and it just keeps charging as you use it.

Personally I wouldn't ever be without lots and lots of solar on a van because even in bad weather you often still get a reasonably trickle of power to charge your battery's. Plus if your panels are fitted at least 2" off the roof, which is recommended so they don't get to hot in summer, then they keep the van considerably cooler on hot days and much quieter inside when it rains.

By the way for cooling on hot days and nights check out Cerafamo Sirocco gimbal fans, they are near enough to silent and really work well in keeping a van cool. The best place to buy them is through boat chandlers in the USA via the net, they are nearly half the price of buying them here. Good luck with it.

These really are the ducks guts for vans,,

timer, 3 speeds, and the best bit is they only draw .4 of an amp

I did a fair bit of looking and went the Fantastic for the Van and boat. Still made in the US. Very quiet and powerful.

http://www.campingworld.com/shopping...-12v-fan/38132

I like the a RedArc Dc to Dc charger in the van, with a a Full River in the Van also. Anderson plug from the Disco to the redarc in the Van. Red arc charges the van batt fully and also I have same gauge wire going from Anderson to the 3 way fridge...ie 3 way being powered by the truck with a motion detect Fridge Switch running interference at the fridge. Wicked set up. When I get to camp site, just disconnect the Anderson plug from the truck and plug in 160w portable solar panels and the redarc senses the change and commences charging the van batt as an MPPT solar regulator.

Cheers

Ho, ho, ho.
I've just ordered the 15 Amp regulator from this mob
Solar for Motorhomes and Boats

It looks just what I need, and with the added advantage of not being made in China.