Battery isolators?

[OuterLimits]

Back in the day, when adding a second battery the choices for battery isolators were diode based (creates a voltage drop), Relays (sometimes cannot handle the load over time), or switched (have to be manually switched).

I am planning on adding a smaller second battery for communications gear, car stereo, and a few LED area/work lights.

I am looking for a battery isolator that is simple and reliable. Affordable would be the hat trick!

I am sure modern tech has created better solutions and am curious what you are using, along with the pros and cons.

Thank you, TR

 

[Jet_Pack_Jesus]

Hey so I'm working on the same problem. I ended up doing a continuous duty solenoid it's 200 amp rated (ch24213). I don't plan on ever running close to that. We have been using them at the car audio shop that I work at for year with little to know problem. I will be taking an ignition lead to turn it on. I'll be running all of my accessories off of it. It allows faster charging over a battery isolator. You could also run it off a switch. you can get them in many different amp ratings. Just my thought good luck let me know what you end up going with thanks.

 

[OuterLimits]

Hey so I'm working on the same problem. I ended up doing a continuous duty solenoid it's 200 amp rated (ch24213). I don't plan on ever running close to that. We have been using them at the car audio shop that I work at for year with little to know problem. I will be taking an ignition lead to turn it on. I'll be running all of my accessories off of it. It allows faster charging over a battery isolator. You could also run it off a switch. you can get them in many different amp ratings. Just my thought good luck let me know what you end up going with thanks.

I appreciate the reply, especially the real world usage at the car audio shop.

My gut instinct was a solenoid/relay solution. Affordable and door knob simple.

Thanks, TR

 

[000]

When I built the dual battery system for my Tacoma I went with the blue sea marine si acr automatic relay from amazon and bussman heavy duty breakers from the local diesel shop. It has worked out great for keeping the deep cycle charged for the fridge and winch. I put one breaker between the deep cycle and the relay and one between the truck battery and the relay so I can disconnect everything with two switches when I don't want it to be charging in between trips and protects everything just in case. Since I had some free 1ga cable and an extra deep cycle I think the whole project costed me about $175. The relay starts charging 30 seconds after the truck is started and isolates the two batteries. After some research I learned that Alternators do not fully charge batteries so before and after trips I put the deep cycle on a trickle charge to keep it topped off. I noticed a dramatic increase in life when running the fridge with out starting the truck and supposedly this will help increase the overall life of the deep cycle. Be sure to use the same type of batteries together, two agms or two lead acid etc...


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[Longshot270]

You could also look at the onboard charge controllers for marine deep cycle batteries. Charges your trolling motor battery when the engine is running but isolates when it isn't. It let's you run different battery capacities, types and demands trouble free.

 

[Tim]

I've had one of the simple voltage sensing relays for a about 15 years. Basically just a solenoid or relay with a bit of electronics to detect when the alternator is putting out enough to charge both batteries to trigger it. If you go down the route of just a relay or solenoid I would recommend a 12v surge protector as well, just to suppress any voltage spikes. In my case I've probably outgrown that style of split charge system just because I depend on the auxiliary battery for longer periods and need it to be fully charged. As has already been said an alternator will only ever charge your battery to about 75%. This is fine for starting duties but if you start depending on that second battery, not so good. This is where the expensive BCDC units come in... basically like plugging your battery into a charger with all the various modes to optimally charge it. Some modern vehicles can only support this type or require some modification to the alternator otherwise they reduce their output when the main battery is charged and won't continue charging your second battery. The BCDC style is also great when your batteries are of dissimilar types. That said the original solenoid/relay type and a solar panel (portable or fixed) to top up the second battery is also a good option. If you won't to get really basic I've also seen 'boat' switches used. Basically a high current switch that gives you options on disconnecting either battery or joining them together


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[W4P]

Agree!trying to save the pennies to invest,and that's the word.... in a ctek smartpass system. From my research only appears top of the list. Used everywhere in Australia. Allows input from alternator,charger, solar!!!!

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[Jet_Pack_Jesus]

Wow those are not cheap but they look great of you plan on adding solar to the setup

 

[Flipper]

Blue Seas Systems battery link

 

[Tim]

Agree!trying to save the pennies to invest,and that's the word.... in a ctek smartpass system. From my research only appears top of the list. Used everywhere in Australia. Allows input from alternator,charger, solar!!!!

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Another option is the redarc brand, made in Australia. http://www.redarc.com.au


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[OuterLimits]

Another option is the redarc brand, made in Australia. http://www.redarc.com.au

There's always a lot of cool stuff down under, but price and shipping is usually a show stopper to get it to the states. TR

 

[Flipper]

You could also look at the onboard charge controllers for marine deep cycle batteries. Charges your trolling motor battery when the engine is running but isolates when it isn't. It let's you run different battery capacities, types and demands trouble free.

This is a product by Blue Seas Systems called a battery link, I have been using this in my truck for years with great success. When you start your truck the link senses the alt charge and links the deep cycles to your alt. When you turn off your truck after a min it disconnects the deep cycles. I used to do Marine electronic and electrical installs before I retired. Easy to install and bullet proof. On the output of the link is where my solar panel controller is connected. I run two group 31 AGMs with a Batt selector switch so I can charge batt 1 or batt 2 or both. The deep cycles power all my D.C. accessories , radios, and a 2000w pure sine wave inverter. You can find them on amazon for $100

 

[Overland Ranger]

You want cheap no hassle ford ignition solenoid truck off secondary in use, truck on, both charging

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[Jet_Pack_Jesus]

That's a cheap way for sure. But they are only rated for 30 second with ten minutes down before they say you should use it again. Continuous duty is the only way to go

 

[shoredreamer]

Blue Sea ACR. It's a voltage sensing relay. Combines batteries when it senses a charge and isolates your batteries when voltage drops on either battery. Just wire it up and forget about it. Solid, well made marine electronic parts with great customer service. Look up 'Blue Sea Add-a-battery 7610'.

 

[jumpshowhigh]

I started with solenoids and eventually graduated to solid state products. Not cheap, but Perfect Switch out of San Diego is by far the best out there. I have a drawer filled with all kinds of broken dual battery products ...from solenoid, to "smart" solenoids, to blue heat-sink brick isolators...I finally realized that sometimes there is a correlation between cost and quality and Perfect Switch makes all others look like they're rubbing sticks together. They have dual rectifiers that can go up to 600 amps continuous and I know enough about electrical engineering to appreciate what it takes to do that. For years people touted "solid-state" but the technology was green. These guys in San Diego figured things out and since I bought a 150 amp dual rectifier for my Land Cruiser, it's been bullet-proof. Big fan of their work.