Second battery idea - what recommendations do you have?

[chops749]

Hello,
I have a third gen Toyota Tacoma that I have been slowly building. My father gave me a spare 200AH battery from an Airstream that he is restoring (bought at a steal...like $1500 for the trailer). I have built a simple battery box to power my fridge, etc, but I would like to add it as a house battery box that can come out if needed. So, I'm thinking of running a dc to dc charger, mounted under the hood, and running heavy gauge wire and powerpoles to the truck bed. I would also eventually add a solar charger as well.
I can't afford a TON on this setup, so what dc to dc chargers are relatively "budget friendly" and do you think this is a viable option?

Thanks in advance!

 

[shade]

What do you know about the battery?

 

[chops749]

https://www.amazon.com/Renogy-Batte...200ah+battery&qid=1562525649&s=gateway&sr=8-2

here's the battery...

 

[luthj]

This charger is inexpensive, and has a decent feature range. No personal experience.

Amazon.com: Renogy 20A DC to DC Battery Charger for Flooded, Gel, AGM, and Lithium Batteries Using Multi-stage Charging: Automotive

Buy Renogy 20A DC to DC Battery Charger for Flooded, Gel, AGM, and Lithium Batteries Using Multi-stage Charging: Battery Chargers - Amazon.com ✓ FREE DELIVERY possible on eligible purchases

amzn.to

If you can give us more details on your usage, we can provide better suggestions. Where is the battery going to be mounted? What are you running off it? Solar? Driving vs camping time?

Have you done a capacity check on that renogy battery? Being used, it could have been abused. No reason to build your setup around it, and find its only got half its normal capacity.

 

[shade]

Have you done a capacity check on that renogy battery? Being used, it could have been abused. No reason to build your setup around it, and find its only got half its normal capacity.

That's what I was getting at. I've been given "good" batteries, and promptly took them to the recycler.

 

[shade]

Here's a discussion on the new Renogy chargers.

https://www.expeditionportal.com/fo...ps-or-40-amps-flooded-agm-gel-lithium.204421/

If I was going to use one, I wouldn't mount it in the engine bay. I think people installing these under the hood will be disappointed. I know the ad copy says "Built tough for all conditions", but the manual says otherwise:

CAUTION!
Do not operate the product –

• In salty, wet, or damp environments
• In the vicinity of corrosive fumes
• In the vicinity of combustible materials

Also:

8.2 Installation instructions
When selecting the installation location, pay attention to the following instructions:
• The battery charger can be installed horizontally as well as vertically.
• The battery charger must be installed in a place that is protected from moisture.
• The battery charger may not be installed in the presence of flammable materials.
• The battery charger may not be installed in a dusty environment.
• The place of installation must be well-ventilated. A ventilation system must be available for installations in small, enclosed spaces.

The minimum
• The battery charger air inlet and air outlet must remain free.
• At ambient temperatures higher than 40 °C (ex. in engine or boiler rooms, direct sunlight), the battery charger may switch off, although the power of the connected loads is below the rated load (derating).
• The device must be installed on a level and sufficiently sturdy surface.

 

[shade]

Also, in an application like yours, the charger is typically located at the battery box.

And @luthj will surely correct me, but I believe all DC-DC chargers perform better when physically located near the battery to be charged, since they're designed to boost voltage to the battery for better charging. Running a long run of wire from the charger could introduce voltage drop, which would degrade the performance of the charger.

 

[luthj]

All chargers work best when they have low voltage drop between the charger and the battery. Some chargers (not the renogy) have a zero-current voltage sense wire, so they can compensate for voltage drop between the charger and battery.

Generally you want less than 2% voltage drop round trip between the battery and charger.

All of shade's other suggestions are valid. I would avoid having the charger under the hood for a host of reasons. A splash proof box in the bed, or just mounted under a seat would work well.

 

[chops749]

Thanks for the info. The battery is brand new. My dad could t fit the second battery where he wanted it so it became mine. As for mounting under the hood, I’m not tied to that decision and could absolutely mount it either in the cab or physically on the box in the truck bed.
In terms of power usage it’ll primarily be for running my ARB 50qt fridge while stationary for a couple of days, charging a kids iPad, the occasional phone, and on rare occasions my HAM radio go box.

 

[shade]

Thanks for the info. The battery is brand new. My dad could t fit the second battery where he wanted it so it became mine. As for mounting under the hood, I’m not tied to that decision and could absolutely mount it either in the cab or physically on the box in the truck bed.
In terms of power usage it’ll primarily be for running my ARB 50qt fridge while stationary for a couple of days, charging a kids iPad, the occasional phone, and on rare occasions my HAM radio go box.

Dad sure was nice to give you that beast. At 20.5" x 9.4"x 9.4", are you sure you could even fit it under the hood? It's also heavy enough that you'll need to support it well. I've seen some people stuff two Group 31 batteries into a tight spot in an engine bay, then have all the weight cause problems.

 

[luthj]

I am quite dubious that battery will fit under the hood. Note that is can be mounted on its side, but cannot be mounted upside down (at least I think so). It will need to be very well supported as mentioned, or you may find yourself stranded when it breaks free, causes a fire, and smashes something important (saw this happen on a bus once...).

 

[FJR Colorado]

That battery is huge and heavy as hell. I just put a 100AH Renogy Gel battery in an off-grid cabin and had to build shelf supports to keep it from crashing. Yours is more than double that weight.

See my build thread for my 2006 Tundra. Go discrete solar and put it all in the bed.

You may just want to sell that battery on CList and get something more manageable and less weight.

 

[chops749]

I wasn’t planning on putting the battery under the hood. Just the charger, then run a pigtail with Anderson connectors to the box in the back. I can’t really sell that battery because there is a small indentation in the case. It’s not cracked at all, but could not be returned. @FJR Colorado ill check out your thread.

 

[FJR Colorado]

I wasn’t planning on putting the battery under the hood. Just the charger, then run a pigtail with Anderson connectors to the box in the back. I can’t really sell that battery because there is a small indentation in the case. It’s not cracked at all, but could not be returned. @FJR Colorado ill check out your thread.

Here's a link:
https://www.expeditionportal.com/forum/threads/2006-1st-gen-tundra-doublecab-build.127252/page-2

Soon, I hope to post up my off-grid cabin solar install.

If you do mount that 200AH in a Tacoma bed, it will give you 120+ pounds of weight on the rear axle. Sometimes not a bad thing. You'll also have enough power to light up a condo

Depending on where you live, a nice Renogy 100W panel will keep that thing well-juiced.

 

[chops749]

Here's a link:
https://www.expeditionportal.com/forum/threads/2006-1st-gen-tundra-doublecab-build.127252/page-2

Soon, I hope to post up my off-grid cabin solar install.

If you do mount that 200AH in a Tacoma bed, it will give you 120+ pounds of weight on the rear axle. Sometimes not a bad thing. You'll also have enough power to light up a condo

Depending on where you live, a nice Renogy 100W panel will keep that thing well-juiced.

HA! I know it's a bit large, I plan on eventually moving it to my trailer. For now, it'll definitely work.