Adding second battery

timdebs

Well-known member
I am adding a second battery. I have the Inteli Power Converter 9280. Can the converter handle a second battery or do I need to get a battery selector switch so I can choose battery 1 or battery 2 or choose both? I am planning on wiring the batteries positive (battery 1) to positive (battery 2) and same for negative. Thank you for your help. timdebs
 

2010augusta

Well-known member
The factory converter can easily handle multiple batteries without a need for a selector switch. We have been using 2 batteries since the 2 day we had the unit. Just make sure the convert is not powered when disconnecting and connecting the batteries.
 

timdebs

Well-known member
I added second battery and disconnected shore power, lights, fan, etc worked great. I let the batteries drain down and connected back to shore power to make sure batteries would charge back up. Checked the next day and nothing worked on battery power everything dead. Plugged back in and naturally everything works. Any ideas?
 

timdebs

Well-known member
I have checked all. I charged one battery and hooked it up like it used to be. Unplugged from shore power and still dead on inside. Test panel won't even light up.
 

beardedone

Beardedone
I might be all wet here but if you used the converter to charge just one battery and it was a six volt battery wouldn't that cause a problem! If you have two 12 volts then there is no problem.
 

timdebs

Well-known member
The battery disconnect is turned on. I tested the positive and negative with volt meter and get zero. I thought maybe it has to be hooked up to battery to have any power. I connected the battery I charged up with a battery charger. The meter read 27.6. I checked the 3 fusses on back of the converter, all good. I also checked in fuss panel (both of them) and all is fine there also. The reason I added a second battery is because the battery I had kept running down so fast. The checked out good, but to be on safe side I went ahead and bought 2 new batteries. How can I check to make sure converter is charging?
 

timdebs

Well-known member
I might be all wet here but if you used the converter to charge just one battery and it was a six volt battery wouldn't that cause a problem! If you have two 12 volts then there is no problem.

I had one 12 volt battery to start with. Now have 2 12 volt batteries, same size and make.
 

2010augusta

Well-known member
Okay now I am really confused. What kind of battery were you testing to get 27.6 volts? A normal "good" 12 volt battery will output no more than 14.4 volts. did you somehow hook the 2 batteries up in series and not in parallel?

To check the converter just disconnect the shore power, disconnect the batteries, then reconnect the shore power and then check the voltage at the battery cables, it should be in the 14.4 volt range.

The three fuses on the converter are there just for reverse polarity protection.

If you pulled on the factory cables at all, you might have pulled a wire out of the converter, the set-screws that hold wires are know to become loose and lose connection with the wires.
 

boatto5er

Founding VA Chap Ldr (Ret)
Tim,

Sounds like Alan has hit on a possible problem. If the batteries are wired in parallel they shouldn't be reading over 14.4V.
 

timdebs

Well-known member
I have two 12 volt batteries. I only have 1 hooked up right now that is 80% charged the other battery is not hooked up and sitting on driveway. Before I hooked the battery up I tried to test the converter with volt meter. I did not get a reading. I thought maybe a battery needed to be hooked up to the charger before it knew to send a charge, so that is when I hooked up the battery (just one). Put the volt meter on it and it read 27.6 (had volt meter set on ac rather than dc), with the volt meter set on dc it only read 12.9. Disconnected the converter just to see what the reading would be on the battery and it was 12.8. So apparently the converter is not charging, right? I will check the cables tomorrow and make sure did not pull anything loose. Hope this helps. Tim
 

newbie

Northern Virginia
The 27.6 volts is really weird. What is the voltage of the battery that is on the charger and 80% charged?

John
 

newbie

Northern Virginia
And just so I'm clear, what is the voltage of the battery sitting in the driveway?

John
 
The 80% charged battery is 12.8 and I charged the other battery to 100% overnight on my charger at home and that reading is 13.08. I had the volt meter set on ac when trying to the voltage coming out of the converter (I just figured since I was hooked up to ac and was looking for voltage coming from the converter that the volt meter should be set on ac) that is when I got the 27.6 reading. I should have had the volt meter set to dc. When I did set the meter to dc the reading I get on the battery (not hooked up to converter) is 12.8. When I hook up the converter and check the battery the reading I get is 12.9. I am thinking like Alan suggested I might have pulled some wires loose when moving the converter around for me to get to. I will check today.
 
Tim:
I would expect to see about 12.6 volts on the battery without a load and without charging on. I would expect to see about 13.6 volts with charging on.
Adding another battery in paralell is simply like adding more lead plate surface area. Heck, that is what they do within the battery cells themselves. Each pair of plates will generate 2.2 volts due to the laws of electrochemistry and the chemicals involved. The amp hours of each plate set is determined mainly by its surface area. The cells in batteries have a bunch of plate sets wired in paralell to increase the effective plate area and thus the amp hours. The 6 cells are then wired in series to get the nominal 12 volts (actually 13.2 volts).
Having said that, it is important to closely match the paired batteries in size, brand, and age. Otherwise, the weaker battery robs charge from the stronger battery.
 
It sounds like you may have popped an in line ckt breaker. On my Bighorn they are behind the battery on what looks like a terminal block but is actually a set of breakers. If you feel under the left side of the cables connections you may find a button popped out if so push it back in and that may solve your problem.
 
I have found a couple of issues. (1) took battery disconnect switch apart found nuts not tight, was able to turn with fingers. (2) was able to pull cable out of connector on battery disconnect, not crimped properly. All wires/cables used were red so it is really hard to trace to make sure everything hooked up right. There is a white wire hooked to the negative post on battery goes down in belly of camper, I assume it is connected to frame somewhere (anybody know where). Is this a good assumption? I am trying to make sure all grounds and wires are securely fastened.
 
First picture are wires going down into the belly. Second picture tracing wire nightmare. Third picture is battery disconnect switch with all red wires. Fourth picture is another wire nightmare. Fifth picture is ground block I am assuming? Sixth picture is positive cable not securely crimped in connector. Seventh picture is fuss panel. Is the bottom supposed to look like that?
 

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Fuse panel looks fine. Fix the disconnected wire at the disconnect and check the DC output of the converter at the converter and at the battery cables. if you get voltage both places your good to reinstall both batteries.
 
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