P1000 Charging 2 Batteries with True Power Isolator

[ShadowAero]

I have 2 batteries with Tru Power Isolator. When running the voltage on battery One is 14+. With off 12.8
Battery Two is about 11.7-12. I would like to put it on 3amp battery maintainer to trickle charge both batteries. Should i connect maintainer to battery One? The reason for confusion is i don't understand why battery two voltage is so low. I thought after charging battery One the isolator would charge battery Two.
Note: Only the engine Fan (marine bilge fans) are connected. Waiting to install lightbar, etc.

This is with engine off. All accessories will be on battery Two. But only fans work now.

This is with engine on

 

[Admin]

 

[mbjeepxj]

It should be charging battery2 with the engine on. I only have a volt meter on my second battery right now and it goes up to 14+ right after starting my engine.

My battery2 reads 12.7-8 with the engine off and only goes down to 12.5 after hours of listening to music withbthe engine off.

Also, my battery tender will charge both batteries (blue light on isolator comes on). You can even hook the battery tender to either battery and it will charge both. The Tru isolator is bi-directional so you can't even hook it up backwards.

I would check your wiring for loose connections first. Does rhe blue light on the isolator come on when the engine is running? If so, and it still reads that low, then have your second battery tested/replaced, though I would think it would still read 14+ with the engine running with or without a bad battery.

Edit: If you have a handheld multimeter you should use that to check voltages for a second opinion. Could be you just have a junk volt meter in your dash.

 

[ohanacreek]

It should be charging battery2 with the engine on. I only have a volt meter on my second battery right now and it goes up to 14+ right after starting my engine.

My battery2 reads 12.7-8 with the engine off and only goes down to 12.5 after hours of listening to music withbthe engine off.

Also, my battery tender will charge both batteries (blue light on isolator comes on). You can even hook the battery tender to either battery and it will charge both. The Tru isolator is bi-directional so you can't even hook it up backwards.

I would check your wiring for loose connections first. Does rhe blue light on the isolator come on when the engine is running? If so, and it still reads that low, then have your second battery tested/replaced, though I would think it would still read 14+ with the engine running with or without a bad battery.

Edit: If you have a handheld multimeter you should use that to check voltages for a second opinion. Could be you just have a junk volt meter in your dash.

That's not correct it is one directional the main has to reach 12.8 or above and it will begin to charge the secondary

If you connect the battery tender to the main once it is charged the Blue led will come on on the ISO and the secondary will start charging.

 

[Eltobgi]

I have 2 batteries with Tru Power Isolator. When running the voltage on battery One is 14+. With off 12.8
Battery Two is about 11.7-12. I would like to put it on 3amp battery maintainer to trickle charge both batteries. Should i connect maintainer to battery One? The reason for confusion is i don't understand why battery two voltage is so low. I thought after charging battery One the isolator would charge battery Two.
Note: Only the engine Fan (marine bilge fans) are connected. Waiting to install lightbar, etc.

This is with engine off. All accessories will be on battery Two. But only fans work now.
View attachment 54868

This is with engine on
View attachment 54871

Doesn't appear to be charging auxiliary battery when started something is not right! How about sharing a wiring diagram of the way you have it hooked up.

 

[ShadowAero]

Doesn't appear to be charging auxiliary battery when started something is not right! How about sharing a wiring diagram of the way you have it hooked up.

Thanks for responding Eltobgi, here is pic.

A big red cable goes to each batteries positive. Grounded to a ground buss. The two skinny red are each connected to a separate voltage gauges. The voltage gauges are connected to a relay which is keyed to only turn on when key is on. The picture doesn't show it but i have a PDM connected to battery 2 which supplies power to all switches except winch. I only have engine fans on switches. The switches are prewired for later when i add accessories. Winch is directly wired to switch and battery 2.

The blue light that is showing below is with Pioneer off. It will stay on until second battery drop below 12ish (can't remember number)

 

[Eltobgi]

Thanks for responding Eltobgi, here is pic.

A big red cable goes to each batteries positive. Grounded to a ground buss. The two skinny red are each connected to a separate voltage gauges. The voltage gauges are connected to a relay which is keyed to only turn on when key is on. The picture doesn't show it but i have a PDM connected to battery 2 which supplies power to all switches except winch. I only have engine fans on switches. The switches are prewired for later when i add accessories. Winch is directly wired to switch and battery 2.

The blue light that is showing below is with Pioneer off. It will stay on until second battery drop below 12ish (can't remember number)
View attachment 54986

What I would try at this point is removing anything supplied with power from secondary battery one at a time, including winch. What I would like to see is if you have a parasitic draw from something! As you know the secondary should almost immediately respond to the 14.3 volts being powered to it opening the isolater and allowing the secondary to charge! If by removing accessories we can get your auxiliary volt meter to register at 14.0-14.3 we simply reconnect what has been disconnected one by one until we find the source of the draw. Hope this helps.

 

[knuckledeep]

Mine started the same thing this weekend i have to wait for it to come home and check it out could be a loose connection or bad isolator

 

[ohanacreek]

Mine started the same thing this weekend i have to wait for it to come home and check it out could be a loose connection or bad isolator

They are not very waterproof at the battery connections, joey had one go out, I checked mine and it had condensation in it so I dried it in rice and put silicone around the battery connections where they go through the housing.

I was in a hurry and didn't put it in my build thread.

 

[knuckledeep]

They are not very waterproof at the battery connections, joey had one go out, I checked mine and it had condensation in it so I dried it in rice and put silicone around the battery connections where they go through the housing.

I was in a hurry and didn't put it in my build thread.

I dont know how moisture got in there lmao

 

[Plumber101010]

I've always just used a marine battery switch. Far less complicated, much cheaper and it's bulletproof, will never fail.

Switch is $30 and has battery 1, battery 2, both or off.

Just leave it in the both position and will charge both of them but you risk having both batteries go dead also.

So what I do, is leave it in battery 1 for a week and then switch it to battery 2 for a week, alternating back and forth.

Both batteries are maintained and if one battery goes dead, put to battery 2 and you have a spare ready to go and even better, put it on both and charge the dead battery back up!

I have them installed on all of my full size trucks and haven't done it on any of my toys yet but it's so simple, cheap and easy to do it that way!

Mount the switch inside the cab and you're ready to go!

 

[joeymt33]

As for charging, I have a 12 V socket in the driver side fender where I plug in the battery isolator which is connected to the primary battery. Once the primary battery reaches 13.2 V it will then make the connection and start charging the second battery.



The 12 V socket is used for other things like a bilge pump for washing off the windshield and radiator and spotlights.

 

[ohanacreek]

Stole another on of your ideas

OptiMATE Cable O-40, Weatherproof SAE socket, panel mount https://www.amazon.com/dp/B01N57XLNS/?tag=sxsweb24-20

 

[Eltobgi]

Love the switch! Mine has on/off/combine! The Combine feature on the switch makes it superior to other dual battery systems out there!
The only difference is that I run an Automatic Charging Relay along with the switch which is better than the isolator in my opinion and like all blue sea marine equipment has a lifetime warranty!

Q: How does an ACR differ from a battery isolator?
A: Battery isolators use one-way electrical check valves called diodes that allow current to flow to, but not from, the battery. ACRs use a relay combined with a circuit that senses when a charging source is being applied to either battery. ACRs are more efficient than battery isolators because they create little heat and consume minimal charging energy.

Click here for more info...

SI-ACR Automatic Charging Relay - 12/24V DC 120A - Blue Sea Systems

 

[Bigtee]

As for charging, I have a 12 V socket in the driver side fender where I plug in the battery isolator which is connected to the primary battery. Once the primary battery reaches 13.2 V it will then make the connection and start charging the second battery.

View attachment 55071

The 12 V socket is used for other things like a bilge pump for washing off the windshield and radiator and spotlights.

Joey, did you just wire from the plug to the main battery side of your isolator and then just ground the other wire?

 

[Hondasxs]

Post reopened.
This post was about the automatic True Power Isolator.

If there are better simpler method please start a new post we can direct members to.

 

[joeymt33]

Joey, did you just wire from the plug to the main battery side of your isolator and then just ground the other wire?

It’s wired directly to the main battery.

When the main battery reaches 13.2v, the isolator closes and then it starts charging the AUX battery.

I also used a 15 amp fuse close to the battery.

 

[Bigtee]

It’s wired directly to the main battery.

When the main battery reaches 13.2v, the isolator closes and then it starts charging the AUX battery.

I also used a 15 amp fuse close to the battery.

Thanks for the info

 

[knuckledeep]

Found the problem his lower connection nuts on the isolator were loose not making complete contact tighten up all works normal

 

[ShadowAero]

I'm glad you found the problem! You saved me a big headache.
Moral of the story: Make sure you keep you Nuts tight!

 

[knuckledeep]

I'm glad you found the problem! You saved me a big headache.
Moral of the story: Make sure you keep you Nuts tight!

Wife checks mine all the time