battery charging from the car...

[inveratta]

By the time I get to the beach its too late to get the boat and charge up the battery overnight if required...The next day I have up to an hours drive with the boat on the trailer ...and I have an anderson plug in the boot of the Pajero direct wired to the battery.....for the trailer winch

Is it ok to plug a lead into this and run back to the boat battery..or do I need further regulation?

[Volvo]

12 to 12volt batterry charger adjascent to your battery.Anderson plug from your vehicle to Anderson plug prior to charger and offcourse correct size leads to battery/s.
Should do the job nicely , what i do when its overcast keep caravan batteries topped up keep fridge freezer chugging along.

[jclay1773]

1hr drive in the car will give your boat battery very little charge.

[Cox76y]

Bit of info here that I found informative.
https://allaroundoz.com.au/2017/08/12/alternator-or-dc-dc-charging/

[gazza2006au]

Inveratta it will work but what u really need to know is the amp output at the anderson plug in your boot, it may be devided by your running car battery so if the alternator is outputting 40amps dedicated to the car battery you'll have double the load to charge ie 2x 100ah batteries vs 1x 100ah so if 40amps is coming thru u will be getting 20amps per battery but im unsure how two batteris connected in parallel would work out how many amps each battery get from the power supply

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[scottar]

No need for further regulation. It's effectiveness will be directly related to the cable gauge. Voltage drop / cable resistance over that distance may limit it's current delivery. You could look at a DC-DC charger but they are pricey and will limit the current delivery in their own right with short charging periods. If you do get a cable made, make sure the system is fused or through a breaker at both ends as either or both batteries will deliver current into a short circuit.

[gazza2006au]

I would put a clamp meter on the cable to monitor the amps if your getting under 8-10 amps over the 1 hour trip it may be more pissing in the wind effort than worth it

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[Noelm]

Why do you think the battery needs charging?

[TheRealAndy]

Why do you think the battery needs charging?

The most logical question (and answer). to OP in this thread

[scottar]

He did state " if required" which sort of implies if it's at a reduced state of charge.

[gazza2006au]

OP may just want a 100% charged battery or the confidence knowing he is topped up

Nothing worst than heading out blind folded i do it tho...

Get out there 75% battery... chase the fish few more cranks.... now at 50% decide to fish into the sunset lights on... now time to leave your at 35% and she just fires up... ahhh lucky

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[Dignity]

As I read it the boat is already at the beach house and may have been sitting there for a while. If that's the case 2 options, install a solar panel, it really doesn't need to be a huge one, I had a extremely good quality 10amp one that worked a treat or stick one of those ctek chargers on while you're away.
The other consideration is that maybe the battery is not in the best condition if an hour of driving doesn't top it up unless something is switched on and pdraining.

[gazza2006au]

A lot of people are using solar panels these days, i remember buying 2x of those 10watt models from super cheap auto 14 years ago the ones that drain your battery when the sun isnt shinnig lol

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[Dignity]

They needed a regulator i would think, the one I had already had it inbuilt.

[gazza2006au]

Yeah solar technology has come leeps a head today

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