Secondary Battery Charged via Bed Outlet

Hey guys,

Long time tacomaworld lurker here. I've never posted anything before but I couldn't find anything on this idea I had for a secondary battery. I'm brainstorming some ideas mounting a second battery in the bed of my truck and using a 1.5 amp trickle charger to charge the second battery while driving the vehicle. If anyone knows if this is a horrible idea or if this would work without exhausting the main engine bay battery please let me know

Thanks

 

It sounds like you want a spare battery mounted in the bed and will keep the 2nd battery charged with a trickle charger. Is that correct? Will the extra battery be wired into anything else or just charging with a trickle charger? Wondering what you will be using the spare battery for.

 

Correct. However, I will only be charging the second battery when Im driving the vehicle via the outlet in the bed through the trickle charger. The secondary battery will not be wired to anything. My plan for the second battery is simply to have access to it to when camping or when the truck is off so that I can use a small inverter (

$27 NDDI 200W Car Power Inverter 12V DC to 110V AC Converter with 3.1A Dual USB Quick Car Charger Adapter(Black)

https://www.amazon.com/gp/product/B07T7D1Y6X?ie=UTF8) to charge a laptop, phone, etc.

 

I would not recommend this. First while driving the inverter only has 100w output. Secondly the system efficiency is low because you loose power through the inverter and then again power by inverting it down again.
Probably better would be to get a power station like a Jakery and then either plug it into the outlet on the bed or maybe use a solar blanket what you can directly connect.

you can easily remove them and only take them when you know you might need it and also you can charge them at home when not in use

 

What labbi said or get the correct charger to charge a secondary battery such as a DC to DC charger
https://www.redarc.com.au/battery-chargers/in-vehicle-chargers

 

Thanks for the ideas guys. I will probably end up going the solar blanket trickle charge route, as true DC to DC inverters are $$$.

 

If you're looking for an I expensive alternative, get an isolator and run some wire from your battery to the bed with a circuit breaker on the end near the truck battery. I have the isolator mounted in the bed cubby along with a fuse panel for the lights and usb/12V plugs.

 

You can also use your trailer plug to charge it. It's set up to charge the break away battery on a trailer.

 

A dc to dc charger would be ideal, but yes not cheap.

My Ford transit came with a isolator similar to what stickyTaco pictured. It charges a second battery for a gas powered air compressor.

The cheap way would be to run a cable to the bed from the primary battery with a short ground cable at the secondary battery. Even if you use a small wire like 10ga, it’ll charge better than a trickle charger. Of course a breaker near the primary battery will be a safety must.

Like reklessTLS suggested, that would work. Just tie into the key on power wire.

If you plan to remove the battery, carry it away from the truck to hook up the inverter, you could use a solar charger to help a bit. But those solar chargers don’t do a whole lot.

 

Just get a big ass AGM battery for the bed and charge it every night. It'll run almost anything 12V you want for several hours during the day.

 

there are no free lunches to be had, and as mentioned using the crap taco inverter to only go back to DC to charge an aux battery is a huge inefficiency loop. Just tap off the trailer battery charge circuit as suggested or run a relay with a dedicated power wire to the new battery with the relay coil triggered off the ignition circuit to sync the two batteries together and charge while driving.

 

If you only need to charge those 2 things, perhaps a jump starter would better suit your needs. Many proclaim to also be able to charge your phone.

I bought the

$175 noco gb70 2000A ultrasafe car battery jump starter, 12V battery booster pack, jump box, portable charger and jumper cables for 8.0L gasoline and 6.0L diesel engines, 7.4"dx3.7"wx12.6"h gray

noco gb70, it charges via cigarette lighter socket.

I recall one jumper made by Clore that comes with an inverter. The popular clore J see all over, the blue one, is somewhat heavy, maybe 30-40 lb. If you go with a heavy model, consider one of those fold up hand trucks.

 

This is the battery isolator in my Ford transit, I believe factory installed, so probably the cheapest one they could find. It seems to work. The second battery is always charged up, I can jump start at the second battery. It makes a loud click when it turns on and off.

 

I have a small battery that fits in the box next to the inverter. It's not huge, but keeps my laptop and phone charged while camping for a weekend. Mainly I will fully charge it at home, but also turn on the inverter to keep it topped up while I'm driving around if I had discharged it a bit. It also powers my shell's overhead LEDs. I chose this one for its dimensions. It fits nicely in the box, with a little extra room for the AC plug and an phone charger cord.

It's a pretty nice thing to have when camping. A slightly larger capacity would be nice. And like others said, the inverter can't charge very fast.

$100 MARBERO Portable Power Station 88Wh Camping Lithium Battery Solar Generator Fast Charging with AC Outlet 120W Peak Power Bank(Solar Panel Optional) for Home Backup Outdoor Emergency RV Van Hunting

https://www.amazon.com/gp/product/B08G1KB88B