Battery isolator charge vehicle battery on shore power

[jjrbus]

I have a new to me 02 Roadtrek on a Chevy chassis.
There is what looks to be a newer 4 post isolator,
I see no name brand or specs on it.
I have been RV'ing long time and never had an isolator before
and assumed they charged the vehicle battery when on shore power.

I am plugged in for a couple weeks
and everything is functioning properly.
My house battery is showing 13+ volts at the isolator terminal
and the vehicle battery is reading 12.25 volts at the isolator terminal.

Should this be charging the vehicle battery on shore power??

[Bobbo]

Grit dog wrote:
^So does a new Trik L Start. It’s a mini DCDC charger.
It’s another way to skin the cat but it’s a poor way except maybe in the case of long term storage with solar maintainer already wired into the house setup.
Makes no sense to continuously draw from and cycle the house batteries, shortening their life, to charge the start battery.

I don't know about your DCDC charger, but the old Trik-L-Start didn't pull any power from the house battery unless it was at, at least, 13.2v. In other words, it didn't pull from the "battery," it pulled from the converter/charger charging the battery.

Grit dog wrote:
If not doing the above just plug in a 120v battery maintainer and keep ‘em separate.

Hence my original suggestion. Permanently install a 120v trickle charger and hardwire it to the breaker panel in the RV. Automatic and permanent.

[Grit_dog]

jjrbus wrote:
Thanks for all the input always greatly appreciated. I charged the vehicle battery in my class A with a selector switch. My Toyota I installed a solenoid bypass switch. The A I had for 10 years with no issue and the Toyota for 7 years with no issue.

I like the idea of the dual smart charger, if it fails is something else I will have to learn to troubleshoot. I do have a Progressive Dynamics smart charger so no ancient tech ruining batteries. I do not see a convenient place for a simple battery switch so will add a continuous duty solenoid and a switch by the driver.

That’s cheaper than an ACR. But serves the same function.

[pianotuna]

jjrbus,

Thanks for letting us know your decision.

[jjrbus]

Thanks for all the input always greatly appreciated. I charged the vehicle battery in my class A with a selector switch. My Toyota I installed a solenoid bypass switch. The A I had for 10 years with no issue and the Toyota for 7 years with no issue.

I like the idea of the dual smart charger, if it fails is something else I will have to learn to troubleshoot. I do have a Progressive Dynamics smart charger so no ancient tech ruining batteries. I do not see a convenient place for a simple battery switch so will add a continuous duty solenoid and a switch by the driver.

[Grit_dog]

^So does a new Trik L Start. It’s a mini DCDC charger.
It’s another way to skin the cat but it’s a poor way except maybe in the case of long term storage with solar maintainer already wired into the house setup.
Makes no sense to continuously draw from and cycle the house batteries, shortening their life, to charge the start battery.
Nvm the loss of efficiency with DCDC charging.
AND like usual folks aren’t answering the OPs question. He wants to charge start batt while on shore power WITH the perfectly good converter he already has. And he’s on the right track.
One could make a case diffenrt batteries different charging needs and batteries fighting each other figuratively. However on shore power with a high powered smart charger (converter) it’s going to keep the house at full SOC easily and any equalization between the 2 systems will happen pretty quick after combining them.

If not doing the above just plug in a 120v battery maintainer and keep ‘em separate.
Don’t complicate things.

[Bobbo]

Grit dog wrote:

pianotuna wrote:
jjrbus,

The best solution is a dc to DC charger. This will be automatic.

Second best is a solenoid that doesn't switch on until the voltage is 13.5 or higher.

I did opt for manual control of my twin 200 amp solenoids. But that was before dc to DC chargers were available at a cost that did not include your first born son.

You’re confused.
OP is taking aboot charging the start battery from shore power…. lol:S

Or charge the house battery from shore power and the start battery from the house battery. That is what the old Trik-L-Start did.

[Grit_dog]

pianotuna wrote:
jjrbus,

The best solution is a dc to DC charger. This will be automatic.

Second best is a solenoid that doesn't switch on until the voltage is 13.5 or higher.

I did opt for manual control of my twin 200 amp solenoids. But that was before dc to DC chargers were available at a cost that did not include your first born son.

You’re confused.
OP is taking aboot charging the start battery from shore power…. lol:S

[pianotuna]

jjrbus wrote:
The idea is to keep the battery charged when sitting next to the house. Traveling it has never been a problem.

That is why I added some solar with a trik-l-start on my class C.

For my car I added a timer and a 2 amp charger. I know the parasitic loss was about 3 amp-hours per day--so I charge it for 2 hours per day.

[jjrbus]

The idea is to keep the battery charged when sitting next to the house. Traveling it has never been a problem.

[MrWizard]

You want the start battery to stay charged while parked at one spot, the easiest way, is install a disconnect on the start battery, no extra wire, no switches in the dash, no drain on the battery,
Cost About $10 at the Auto parts store
Not Automatic

[time2roll]

On 13.3 Off 12.8 140 amp relay $30 Amazon

[pianotuna]

jjrbus,

The best solution is a dc to DC charger. This will be automatic.

Second best is a solenoid that doesn't switch on until the voltage is 13.5 or higher.

I did opt for manual control of my twin 200 amp solenoids. But that was before dc to DC chargers were available at a cost that did not include your first born son.

[jjrbus]

I have replaced the OE converter with a Progressive Dynamics 9245 so I have a modern charger. Been looking at Roadtrek and options. A simple battery switch would be my preferred route but I do not see a convenient place to mount the switch. I have a switch and some heavy wire so that would be the lest expensive route. I do like the KISS way of doing things. Keep it simple spiritually.

A continuous duty solenoid with a switch routed near the driver will be a bit more costly and time consuming and is the preferred route at the moment. Still open to ideas and suggestions. Likely be a couple weeks before I get to this.

[Bobbo]

Permanently mount a small 120v trickle charger and wire it to the RV's power center. When the RV is plugged in, the trickle charger will be working.