UPDATE to "Not charging house bank

[Guest tcbrow]

So, to summarize my previous post, my house bank (4-6volt golf cart batteries) was showing low voltage and the charger wouldn't charge them back up. I would restart the charger, it would kick down and display "Float" within 2 minutes when the voltage was still showing as 11.5. The charger would eventually turn off. The inverter wouldn't come on either (I assumed because of the low voltage). I spoke with Tom Cherry on the phone and we came up with a plan to determine if the batteries were bad or if it was the inverter/charger. I put 2-12 volt deep cycle batteries from my boat into the MH.  The charger just kicked back down to "Float" again because they had good voltage. I tried to draw them down with the inverter and it wouldn't come on. This was telling me, bad inverter/charger. I received my new Magnum 2012 inverter/charger today. As I was surveying the wiring on my old Trace to see how if everything was well marked I unplugged the 2 RJ-11 telephone type plugs that were connected. One was for the remote display and the other was for the Battery Temperature Sensor. As soon as the BTS was unplugged the charger came back to life. Plug it back in and the charger went off. I had charged the 4-6 volt batteries back up with a different charger while they were out (it took a while) so I swapped them back in and everything looked good. I plugged a quartz shop light in and turned on the inverter. It worked fine. I drew the batteries down with the inverter then plugged back in to shore power. Charger kicked in and is charging as I type this. At this point everything seems to be working. I will monitor it for a few days before trying to return the Magnum 2012. 

So, my question now is, how important is the BTS? Will I do damage running without it? I haven't yet looked to see if I can get a new one without buying the whole unit.

Thanks,

Tom

[Ivan K]

Is the temp sensor the kind that bolts to a battery post? If so, I would remove it from the post and test for function. It is not that unusual for them to pass some voltage when the isolation is compromised. They are important in a way to limit charging to safe level with temperature change, otherwise the charge assumes a default temperature no matter how hot the batteries can get.

[vito.a]

I updated our old Trace Freedom inverter to a new Magnum and found the old temperature sensor was not compatible.  

I've left the temp sensor unplugged for the last couple of years with no problems.  I spoke to the Magnum tech guy and he also said no problem.  

If you choose to install the new Magnum inverter you will also need the Magnum remote.  You will have to install a new RJ11 phone plug with reversed polarity on one end.  I changed the cable end up inside the coach as it's easier than laying on your back in the basement.   You will also need to install a new longer ground cable from the inverter to the frame rail in the basement.  

[Guest tcbrow]

Ivan, the Trace BTS looks like it was glued to a battery at one time. As far as I know it was just laying on a battery for as long as I've owned it. The BTS that came with the Magnum is the bolt-to-terminal type.

Vito, I bought a new remote with the Magnum. I assumed the ends were the same, end to end. If I end up using the Magnum I will double check the cable that came with it. I anticipated an issue with that and also figured out that rewiring a new end would be easier than routing a new cable.

Thanks guys.