New solar; isolator with diodes functions; smart separator?

pfacdb · 07-04-2015, 09:55 AM

Currently adding 300W solar to 2011 Roadtrek 190 that is in last couple of weeks of 4wd conversion at Boulder Offroad. I have diligently read the great posts on isolators, separators, and smart separators, and am grateful for the great info here.

Solar components are from AM solar consisting of Blue Sky 2512 controller; house is 2 6V AGM; charger is paired well for 3 charging requirements for batteries.

Question: The RT came with and still has a functioning Isolator (diodes) made by Hehr-powerline. From what I have read, I'm not concerned about the voltage draw from the isolator. So be it that the isolator is apparently functioning fine, is there any compelling reason to jump ship and change to a smart separator like the Blue Sea 7620?

I'm on the fast track in terms of learning about electronics, but still overall knowledge is pretty basic, so thanks for tapering any suggestions to my skill level.

Scalf77 · 07-04-2015, 10:11 AM

The isolator should not pose a current draw issue, they do cause a voltage drop from the alternator to the batteries. Depending on the output of your alternator, that may be no really be a huge issue. especially if you follow up with proper charging from other sources such as solar. or 110 charger.

The advantages of the Blue Sea 7620 would then be also that it is bidirectional, meaning that your solar could now charge your starting batteries also. The isolator will not allow that.

The BlueSea can allow for emergency jump start from house, again isolator can't do that.

-greg

pfacdb · 07-04-2015, 10:27 AM

Thanks Greg. The option of the jump starting the van battery in a pinch is certainly a plus. However, I'm still not clear as to what circumstances would lead to one needing to use the solar to charge the van battery? I suppose that would be if the van battery is getting close to it's demise and not holding a charge from the alternator?

**daveb** · 07-04-2015, 10:36 AM

I found solar didn't actually help my starting batteries and seemed to cook my wet cell batteries. After I switched to AGM starting batteries I quit having problems. I still prefer my 7622+remote to an isolator even though I've never had to use it to jump start the van. It is nice to be able to leave the van sit w/o worry about letting any of the batteries drop to a no start or low voltage situation. Batteries are expensive. JMO
[edit] A better setup would be a separate solar system for each battery system but that takes up space.

Bbasso · 07-04-2015, 10:00 PM

I know enough I'm probably going to get myself into trouble by saying this or not...
But with solar panels a proper solar charge controller and two good batteries why would you need to connect it to anything else?
Sure having the ability to top off the starting batteries are nice but if you're main appliances are all the solar then you're starting batteries if in good shape should never go dead.
I recently hooked up my solar system very very simple a 100 watt panel a charge controller and a POS battery and it's amazing I don't have to touch the starting batteries for anything anymore. So they sit with a full charge and ready to go

rockbender · 07-05-2015, 01:22 AM

the voltage drop from the isolator may actually keep your AGM house batteries happier than a separator depending on the type and state of your starting batteries by keeping the voltage closer to what it should be for AGM's.

To answer your question, I would assume that your new solar addition should recharge you to 100% every day (unless you have some large draws we don't know about) so it really isn't necessary to swap out your current isolator IMO. As mentioned before, you won't charge the starter battery but that would only be a concern if you left accessories on that would cause a draw or do not start the van and drive it at least once a month or so.

Scalf77 · 07-05-2015, 07:35 AM

Quote:

Originally Posted by pfacdb

Thanks Greg. The option of the jump starting the van battery in a pinch is certainly a plus. However, I'm still not clear as to what circumstances would lead to one needing to use the solar to charge the van battery? I suppose that would be if the van battery is getting close to it's demise and not holding a charge from the alternator?

I agree you do not need to charge your starting batteries from the solar. Some members of the forum do like that capability. I agree with Dave, unless you have AGM starters,you will prematurely age your starters.

-greg

pfacdb · 07-05-2015, 10:17 AM

thanks all.

Of all things, it turned out I was wrong about having diode type isolator, and instead have the sure power 1315 that was one of the recalled units due to fire hazard.

While I liked the simplicity of the idea of having an isolator, it's obviously time for a replacement due to safety reasons. Just ordered the the Blue Sea 7622. Figured it would be winter before I got a recall replacement from Roadtrek.