I have been reading that an auto combiner (blue sea) is a better option if you require an isolator to be replaced.
Is this true and if so is the blue sea ML SERIES 500A 12V ACR a good choice?
Preter
That's the way I'm going when my isolator needs replaced.
Like this one?
Blue Sea 7622 ML-ACR Automatic Charging Relay with Manual Control 12Vdc 500A (https://baymarinesupply.com/blue-sea-automatic-charging-relay-with-manual-control-12vdc-500-amps-7622.html)
Works OK if you have the same type batteries for start and house. If one side is lithium chemistry the charge profiles and voltages are different enough that I would probably not use one of these.
My solar charges both house and start batteries. My bigger Victron Multiplus will charge both house and start batteries. My Battery to Battery smart charger will charge both house and start batteries while driving. And I have a smaller 40 amp smart charger that will charge house and start batteries when we are plugged in and the big inverter/charger is off. I have no isolator or automatic charging relay devices.
So Roger all you batteries start and house are Lithium?
No, AGM Start and Lithium House. Most of the time even while driving solar charger does all of the work. Charge profile voltages are similar, times are different, so I am using LiFePO4 charge profile.. Two weeks in Wyoming and two more in SD and 5 travel days charging only with solar. SOC on LiFePO4 was 100% when we got home. Start batteries are charged by alternator while driving.
Other than lithium/AGM banks the auto combiner eliminates the chance of dead start batteries if power is applied to the house side.
My mk gels and optima red tops have been perfect since I put in the autocombiner.
Ok great info...
I will check to make sure the battery types are the same.
Is the unit easy to install, as the isolator is or is it more involved?
Peter
I changed the original to a new Cole-Hersee 200 amp with agm's in both places. Seems to be fine. I have the original Heart 2500 inverter-charger
Peter, if you have AGM and AGM or AGM and GEL they are close enough that you can use an isolator or a combiner.
Your alternator may have its normal voltage increased to compensate to the voltage loss in a diode style isolator. If you replace a diode based isolator with a combiner or a zero voltage drop isolator you will want to check to output voltage of the alternator. I think it should be 13.8 to low 14s at the start battery shortly after starting the coach. It will go down as charge comes up.
My start batteries are Flooded Lead Acid Starting Batteries (Canada Proof G3472) and my house batteries are AGM Batteries (Northstar 8MS-AGM-8DK) so I presume I can not use a auto combiner...
Peter
I think I may have to replace my start batteries with Red Top 9002-002 to make that work..
Peter
Naw will work fine. AGM and flooded cells are roughly the same profile as far as my research showed. All new coaches come with combiners
so if i have my coach plugged into a 15 A outlet and install an auto combiner I do NOT have to put my start batteries on a trickle charger (battery Minder) for storage in CANADIAN WINTERS?
Correct. See the blue seas description
Plugging in your coach will not charge the batteries even with a combiner unless you turn on the inverter/charger.
IF the battery charger is temperature compensated as all good chargers are, and if house battery temps are approx. above 90 degrees, with GEL batteries, the charge profile may correctly reduce float below approx. 13 volts, most voltage controlled relay battery combiners will NOT combine, leaving start battery bank not under charge.
Our Blue Sea ACR acts this way often during warm weather. So we also have a diode-based Trik-L-Start that may after the diode voltage-drop, still charge a little with voltages a little above 12.6.
Check Blue Sea specs for voltage close & open preset settings.
Also you may not to use Blue Sea ACR start isolation feature.
We do have a diode-based isolator to handle engine alternator charging that work just fine.
Thanks....The coach will be stored for the impending Canadian Winter, SO high excessive temps will not be the issue.
VERY low temps will.
The inverter (Freedom 25) will be turned on and SET to charge.
I am also considering putting a Lasko "my heat"(plugged in with TC-3 Cold Weather Thermo Cube Thermostatically Controlled Outlets) in both the sewage and manibloc bays to try to keep the temps up.
So plugged in to the coach (plug in's in the bays) will be 2 heaters, and the Battery Minder for the start batteries (UNLESS I go with the auto combiner..)
I guess I should inquire with all these items plugged in, will the 15 A plug in be enough!?
No I do not think so
One heater on 15 amp breaker would work if nothing else was on. On my last coach I could run one heater on a 30 amp breaker
and if I tried to run 2 heaters the voltage would drop. I had a long extension cord, 10 gage wire so I would only run one.
Lasko MyHeat are 200 watt heaters drawing about 2 amps of 120volts, so your 15 amp outlet could be ok as long as there are no other loads on the same panel's circuit breaker. Too much voltage drop should be avoided and measured with heaters on.
In very cold temps we run four Lasko 200 watt heaters in bay areas: water pump, water manifold, sewer drain, & fresh water tank. Also have wireless remote thermometers to monitor temps. To help keep heat from leaking out, we have large sheets of Reflectix with sides tucked inside bay doors.
With Lasko 200 watt heaters, nobody should use light bulbs to keep bays warm as they are VERY dangerous.
Barry thanks for the post info about the blue seas not auto combining when the btms lowers the gel batteries to below 13 volts.
My magnum me arc panel is showing 13.0- 13.1. Was warm in Terlingua, to today. 92
Checked the magnum panel and it shows the Bts temp at 104. So the charger went to 13.0-13.1.
The engine batteries and the house batteries showed 13.09 and 13.14 respectively so they were not combined.
Used the manual switch for a minute to combine the banks and the engine side started to flicker between 13.09 and 13.10 and the charger showed 10amps output.
Interesting. If not gels but flooded or AGM the .2 volts higher settings would have the combiner still working at 104 on the bts as it would be at 13.2 or so.
I suppose I could change the settings to AGM and fool the combiner.
I did not understand your next to last line about the isolation?
The combiner isolates when the starter is engaged is what he is talking about.
Maybe craneman, the sentence does not make sense as written.
Also you may not to use Blue Sea ACR start isolation feature.
I do have the start isolation hooked up.
I think he maybe talking about using the manual connect mode on the combiner to connect the banks in hot weather.
Hi Barry,
I assume you plug in to a 50 A outlet if you run 4 lasko heaters, right?
Before plugging in my 1 or maybe 2 Lasko heaters I am going to have to get draw information about my Heart freedom 25 inverter (which will be on and set to charge)
because I am plugging into 15 A. UNLESS anyone has that info out there and would care to share.
Peter
We hardly use Lasko anymore as we stay out of cold temps. 4 Lasko 200 watt heaters draw about 8 amps total, so 15, 20, 30, or 50 amp would work, as long as other loads don't exceed breaker pedestal limit.
Bob,
We have an LED in the kitchen in our 12v monitor panel that lights up when BlueSea is combining. Also have separate volt meters for house & start bank, all to keep us informed on our 12-volt world.
In addition, we power Blue Sea start isolation feature with ignition (not start) so we don't combine when engine alternator is charging.
As far as our previous discussion, Blue Sea will stop combining (it will open its relay) when battery voltage drops below its specified set point. Which in our coach, based upon the charger's profile, when house battery bank gets too warm (about 90 degrees) charger's float voltage lowers to about 13 volts to prevent damaging batteries.
As stated before, I am tossing around getting a auto combiner instead of replacing the isolator I have.
In viewing it again today (see pics) the right side of the isolator is actually coming apart!
So I guess I should get to it.. but another question arises. The unit below confuses me as to what it is. I presume I will have to replace it as well, but do not know what it is. Any help would be great!
I think the cables are ok (with a little brushing)
Peter
That is the boost solenoid and if it works not necessary to change.
Barry I talked with my guru and he mentioned that the blue seas does not disconnect until 12.75 or 12.6 volts.
The location of the combiner at a distance from the batteries induces a voltage drop. The combiner is seeing the lower voltages hence the disconnect. I am thinking the cabling from the batteries to the combiner is not 4.0 marine fine strand cabling? We may need to see what's actually used. If we want our combiners to work in hot weather we may need to run better cabling to the combiner.
Stands to reason as blue seas is a marine unit and long cable runs to the combiner would be unusual.
Can you see for us what size cabling did Foretravel use from the battery area to the isolator/combiner?
Bob, you could be correct. After being combined, specs show it will disconnect after falling to 12.75v.
Specs for our Blue Sea SI-ACr:
Combine 30 sec 13.6V @ 12 V
Combine 90 sec 13.0V @ 12 V
Open 10 sec 12.35V @ 12 V
Open 30 sec 12.75V @ 12 V
I installed our Blue Sea combiner to heavy battery direct cables at the top of our bay wall 12-volt panel. Combiner is mountedright next to the bay wall panel under the white cover.
My observations are when battery temp is about 90 degrees, the combine LED light is off and house voltage shows about 12.9 volts. I don't think much about the disconnection as we also have a Trik-L-Start to keep start bank under some charge.
Our house are two 8D GELL, start three red-top AGM and both banks seem to last over 10 years. Our Xantrex inverter charger has a custom setting to adjust voltages and temp-voltage coefficient, which I changed. Most chargers do not allow this adjustment and have pre-set coefficients for each profile.
BTW, my previous mention about having ignition tied to Blue Sea Start-Isolation terminal to prevent combining does flash the inside LED lamp.