rfsod48 Report post Posted September 6, 2017 When setting inverter with agm house batteries and sealed lead acid starter batteries do you use the agm setting? Share this post Link to post Share on other sites
manholt Report post Posted September 6, 2017 Hi, Roland. Yes! AGM. I have 2 Magnums and they set themselves, don't know what you have. Share this post Link to post Share on other sites
wolfe10 Report post Posted September 6, 2017 Agreed. The inverter/charger primary job is to charge the house bank. Set your charge specs for AGM. And, unless you have the optional battery temperature probe, re-set them with the seasons to reflect ambient temperatures! Share this post Link to post Share on other sites
rfsod48 Report post Posted September 6, 2017 Brett, reset for the seasons --- does that mean like spring, summer, fall, and winter? Would summer/winter be enough? We live in Michigan and winter in Arizona. thanks for the help. Hi Carl hope your trip went well, like you said it was good to put a face to someone you correspond with. Roland Share this post Link to post Share on other sites
wolfe10 Report post Posted September 6, 2017 Roland, Whether you reset twice a year or with each season depends on ambient temperatures. And, if you leave Michigan late in the fall for Arizona, you may need to reset it again. Look in your inverter/charger owners manual for recommendations. Correct float voltage at 90 degrees F is VERY different than float voltage at 40 degrees F. If you tell the inverter/charger what to do it is very smart! Again, this is IF you do not have the optional battery temperature sensor from your inverter/charger manufacturer. Share this post Link to post Share on other sites
wildebill308 Report post Posted September 6, 2017 Brett, do you know if the optional battery temperature sensor can be added if it didn't come with the unit originally? Bill Share this post Link to post Share on other sites
wolfe10 Report post Posted September 6, 2017 Yes, if your inverter/charger mentions a battery temperature sensor and it has not been discontinued, should be easy. Most connect to the inverter/charger with a telephone-style plug. Now, routing the cable from battery to inverter/charger still needs to be done, but they SHOULD be close together but in separate compartments. But, they can fail-- has a coach a month ago that had a good inverter/charger with 150 amp charger section that would not show over 40 amps charging, even when he purposefully let batteries discharge to 50%. Disconnected the temperature sensor at the inverter and set it to "cold" (coach was in Eagle Nest, NM at 8,000' so that was an acceptable setting). Immediately upon plugging into shore power went to 130 amps. Since he dry camps occasionally, he was wasting a LOT of generator run time. Once you have reprogrammed the inverter/charger, the next time you need to adjust the temperature setting, should take 20 seconds from your remote panel (unless your inverter is REALLY old). So, I have no problem with doing this manually and not spending the $$ and labor to install a temperature sensor. Share this post Link to post Share on other sites
rfsod48 Report post Posted September 6, 2017 My unit is 2005 and it does have input for temp probe but no probe. It is the Xantrex Freedom 458 2000w. The manual states that AGM batteries have a similar charge parameters to wet cell. I have purchased 2 LifeLine 6 volt batteries. So I will set it on AGM and check the temp setting. Anything else I need to do? Share this post Link to post Share on other sites
wolfe10 Report post Posted September 6, 2017 As I recall, the other programmable feature is battery bank size (in amp-hrs). Share this post Link to post Share on other sites
wildebill308 Report post Posted September 6, 2017 Good information. Bill Share this post Link to post Share on other sites
rfsod48 Report post Posted September 6, 2017 Thanks all for the help and info! Roland Share this post Link to post Share on other sites
knnthd Report post Posted November 26, 2017 I am new to the RV world and forum. We purchased our first coach this fall and I'm trying to learn all I can about battery charging issues. We are in Michigan and the coach is stored indoors (unheated) for the winter. The batteries were fully charged when I stored it & I'm contemplating leaving the coach plugged into 115v AC with a timer set at 3 or 4 hrs a day for battery charging. The battery disconnect switch is turned off to prevent battery drain. Is this advisable? We are not into daily freezing temps yet but I'm hoping the above method will prevent freezing and keep the batteries charged. Any insight from members will be greatly appreciated. Ken Share this post Link to post Share on other sites
elkhartjim Report post Posted November 26, 2017 Welcome, Ken. If you post year, make and model of your motorhome plus the inverter make and model it will help you get better answers. My inverter has a float charge rate so I leave it plugged in all the time. What amperage is the 115v you will connect too? Share this post Link to post Share on other sites
dickandlois Report post Posted November 26, 2017 Ken, welcome to the FMCA Forum ! Your plan and thoughts looks good ! The one item that you need to keep an eye on - is the water level ! Because when the timer turns on the charger it goes into bulk charge, then charge to float level charge. The 454 series PDF file is attached. This is a Modified Sine wave inverter / charger system. Rich. Spec.sheets Freedom 458.pdf freedom_sw_spec_sheet.pdf ms_series_owner_s_manual.pdf mms_series_data_sheet.pdf Share this post Link to post Share on other sites
rsbilledwards Report post Posted November 26, 2017 Temperature sensors are not really all that expensive. I am sure there different ones and a good source would be Johndrake.com or solarseller.com, same outfit located in Kingman, Arizona. By far one of the best sources and price wise. Share this post Link to post Share on other sites
knnthd Report post Posted November 27, 2017 Thanks to all for the replies. Our coach is a Tiffin Allegro Bus w/Cat 3126B engine. The inverter is a Xantrex Freedom 458 inverter/charger. I cleaned all terminals and filled the wet cells to proper level just before storage. I plan to check the voltage and/or run the generator once a month so long as I can get access to my coach. I'm not sure if I have the temperature sensor probe on my inverter, I will check that out on my next trip to the storage. Share this post Link to post Share on other sites