Automatic Charge Relay - How to Improve your battery isolator

[ntsqd]

I guess I'm not buying into the "alternators are battery maintainers, not chargers" thing. It is true that the regulators typically used with land vehicle mounted alternators are about a "stupid" as they get, and that may be the reason behind this assertion. That is to say that it's not the alternator's fault that it's not a 'charger' and that it is the cheap, low grade regulator that it's been saddled with that is at fault. I've been looking into how to change that, and it gets expensive pretty fast. In the marine world the alternator is a charger, not a maintainer. They use regulators made by Balmar or Sterling Power to name two (not sure of/if any others). If you click those links be ready for some sticker shock.

Then I stumbled onto the C-Tek D250S which solves the stupid alternator regulator problem (at least for the camper battery(ies)) and provides battery separation all while also working as the solar charge controller too. Though it still isn't inexpensive, it does replace at least one other component making it's purchase a more reasonable option. What we have is working, which is why we don't yet have a D250S to report about. With this unit (or one of the marine regulators) I think that the alternator can become a viable battery charger.

Our truck ('95 CTD does not have an internal alternator regulator, it is external to the alternator and is actually built into the PCM. In our truck's case, these are known to fail while the rest of the PCM continues to work as expected. This makes a marine external regulator very tempting. Except for the cost. But it would put the truck's Die Hard Platinum starting batteries under a multi-step charger instead of a simple, 'stupid' regulator.

 

[nikonron]

Went with #2 welding cable to my camper battery from a Blue Sea ACR, gives me the ability to start the truck from either battery if needed. Solar panel keeps both batteries charged up. Ron

 

[DrJ]

Nice work Ron.
What size wire did you use from the ACR to the truck?

The Blue Sea ACR is meant to handle way more charge than I ever use it for.
It could certainly handle what Ron is doing if the wire gauge is enough.
The gauge of wire is certainly the limiting factor in my system now.

Anyone ever put in a second alternator to run to the ACR?

I've been considering that along with increasing the wire size.

 

[nikonron]

#2 to the main battery also. Whats nice about the welding cable is the flexibility and it has a heavy insulation. Ron

 

[Vic Harder]

nice that you found welding cable in red too. I've only ever seen it in black.

 

[nikonron]

Yes, the red is nice, look on ebay. Ron

 

[SB_Surf]

I had noticed the following on my 2013 Fleet and retested it again today to confirm...

While my truck is running my stock Sure Power 1314A engages bridging the truck and camper batteries together. If I enable my solar system On and turn Off the truck, the 1314A remains engaged and the solar system then shares the charging of the truck and camper batteries. Not excited about that...

If the solar system is then turned Off or a significant load (ie furnace or fridge) is turned On, then the common batteries voltage drops and the 1314A finally disengages.

It appears that the 1314A does not sense the truck-side only contacts to determine when to disengage.

Have others experienced the same 1314A behavior?

Is there a smarter separator/isolator on the market?

 

[ntsqd]

nice that you found welding cable in red too. I've only ever seen it in black.

My local commercial/industrial/vehicular battery store, PowerStride Battery, stocks both red and black Carolprene welding cable as well as lugs and adhesive lined heat shrink to go with it.
In welding cable you need to pay attention to the insulation jacket material being under-hood compatible as not all of them are. From my own investigation Carolprene was, and I've no reason to suspect that it has changed.

I had noticed the following on my 2013 Fleet and retested it again today to confirm...

While my truck is running my stock Sure Power 1314A engages bridging the truck and camper batteries together. If I enable my solar system On and turn Off the truck, the 1314A remains engaged and the solar system then shares the charging of the truck and camper batteries. Not excited about that...

If the solar system is then turned Off or a significant load (ie furnace or fridge) is turned On, then the common batteries voltage drops and the 1314A finally disengages.

It appears that the 1314A does not sense the truck-side only contacts to determine when to disengage.

Have others experienced the same 1314A behavior?

Is there a smarter separator/isolator on the market?

"Dual Sense" is usually considered a desirable option in an ACR/VSR. It is the charging voltage, not the battery voltage, that keeps the separator closed. As you have noted, as soon as the voltage drops below that of a charging voltage the separator opens. I don't see a downside to this behavior.

 

[Stalking Light]

DrJ, I went ahead and got the BlueSea 7622. I'm assuming I can just cap off the switch wires if I want to install it without the switch and then install the switch later? I haven't decided yet where I want to locate the switch but would like to get the SurePower replaced before Expo East.

Thanks.

 

[nikonron]

Charlie, I have the 7622 and did not install the switch, odds are you'll never need it. And yes you can just cap off the switch wires. Ron

 

[DrJ]

Charlie,
Ron is correct that you do not need the switch to run the system. You could manually switch or override the system on the ACR directly. You could also probably figure out when it's on or off based on your trimetric.

The switch just makes all of this simpler. You know if the system is one or off at all times and can change the connection fairly easy.

Here's an example of how I use mine. When I'm driving, I make sure that it's engaged so that I am getting charging for sure if my batteries are really low.
I often disengage it when I'm camping if I'm having a challenge charging just the camper batteries - it's overcast, etc...

I would say most people would be fairly happy with it just in automatic mode and occasionally overriding the system manually.

That's just not me....fiddling with the solar, battery system is part of my experience and fun.

 

[Stalking Light]

Charlie, I have the 7622 and did not install the switch, odds are you'll never need it. And yes you can just cap off the switch wires. Ron

Thanks Ron.

DrJ - I will probably end up installing the switch but that will be a future project, for now I just want to see if I get better charging from the truck.

 

[395traveler]

I have an update on my blue sea isolator installed in a 2015 hawk, side dinette, solar panel and 3 way refrigerator. The install went great, I didn't have to alter any wires and put the isolator in the same place as the old one. I couldn't use my refer on DC before with out running the batteries down very fast. Now when I have it on DC during the day while traveling the DC works without running down the batteries. I leave the isolator on automatic and it works perfectly, no extra power loss from heat. At night with out the help of the solar panel I have to manually set the isolator to keep it charging the batteries and the isolator will disengage as soon as you turn the motor off. I haven't tested this on a long trip yet but so far a huge improvement. It is also so nice just to be able to see what the isolator is doing all the time and not have to wonder.
Peter K.

 

[DrJ]

PeterK,
Great report!
Glad that has worked out well for you.
I've noticed many of the same improvements as you since my install as well.

 

[DrJ]

I did hear back today from a FWC dealer that the Blue Sea ACR is now being used on all new campers in place of the prior battery isolator/separator.
Great work FWC!

Maybe someone is reading our posts!

 

[97grandby]

But are they using the selector switch as well?


1990 Ford F-250
1997 fwc grandby

 

[Stalking Light]

I did hear back today from a FWC dealer that the Blue Sea ACR is now being used on all new campers in place of the prior battery isolator/separator.
Great work FWC!

Maybe someone is reading our posts!

They changed out the thermostat as well to one that was recommended here, so I think the answer is yes.

 

[tree]

very useful write up, I also added the basspro power panel with A and B battery status meter

 

[lonepinetech]

There have been several topics and frustrations about charging our camper batteries from the truck.
I researched a few different options and came up with this mod which I thought might be helpful to share.
A special thanks to Ntsqd - his several great posts gave me the idea.

My FWC had been ordered with a compressor fridge that uses a fair amount of power. One of the sources to replenish the camper's batteries is charging directly from the truck's alternator. The stock system for this by FWC does provide some charging ability but has a few drawbacks. The stock system charges through a sure power 1314a battery isolator. This provides power to the camper but as a battery isolator has three main drawbacks:
1- loss of voltage to heat through the isolator
2- the isolator will not turn on if your voltage in the camper is too low (like 12.5 volts or lower). So when you need the power the very most from your truck you cannot get it.
3- No power could ever been transferred from the camper to the truck batteries in an emergency.

The 1314a does not sense the house side when the relay is opened so it will always attempt to charge the house battery if the starter battery and alternator are putting out full voltage. What happens if the house battery is very low the combined voltage of the two batteries and the alternator drops below 12.5v even though the alternator is putting out close to 14v! That is a really dead house battery!... the relay opens. I have not experienced this with my 1314a but I do have a 100 watt panel so my house batteries and i keep an eye on the battery meter and start the engine before they get that low.


Yes the 1314a does generate/waste heat by design but has not been noticeable at all. The Blue Sea probably is more efficient than the 1314a, but for most this is not noticeable

As far as engine cranking assist.....since FWC wires the banks together with 10 gauge wire it is not safe to use this circuit for engine starting. You must connect the two battery banks with #4 or #2 welding cable when using the engine assist feature of either the Blue Sea relay or the 1314a. I suppose the Blue sea unit could trickle charge the main battery but things start getting complicated with switches and things to remember.

 

[tree]

I was tempted to disconnect the acr that came in my 2016 hawk. since I use a noco onboard charger and solar. im camping for a week in feb. but since the acr turns off when truck is not in use that my batteries will never suck off the truck battery. (hence "separator") correct? like a giant diode