rlaird Report post Posted September 2, 2016 I have a 2005 Dutch Star 4023 with 4 six volt batteries. Want to install a residential refrigerator. Looking for AGM 6 volt batteries for a decent price and Sam's is all sold out. I measured the battery compartment and could install 3 AGM 12 volt batteries in parallel for house batteries. Would this work as well as 4, 6 volt batteries in series with my 2000 watt Xantrex? Share this post Link to post Share on other sites
fhalasz Report post Posted September 3, 2016 I'd stick with the golf cart batteries; they are true deep cycle. For capacity, compare Amp-hours at 20 hours (apples to apples) discharge; obviously, one AH at 6V is equivalent to one-half AH at 12V. Most residential refrigerator installs have 6 golf cart batteries standard; and you will want to have Automatic Generator Start in your system as well. You're looking at major expense here. Share this post Link to post Share on other sites
abyrd Report post Posted September 3, 2016 I just installed residential refrigeration and I have been looking in installing auto-start for my generator. I have a Magnum inverter/charger and have found that the residential refrigerator is requiring 10 amps from coach batteries for normal operation. I only have 4 Interstate 6 volt golf cart batteries and have not experienced any problems going for a couple of days without running the generator or traveling down the road. The auto generator auto-start feature can be added to the Magnum inverter/charger for a couple hundred $ VS $600-$700 to installing the ONAN auto-start. Jim Share this post Link to post Share on other sites
wolfe10 Report post Posted September 3, 2016 rlaird, Several variables, BUT if the same battery technology, same quality and same total AH rating, 12 VDC batteries in parallel are just fine/equal to the 6 VDC in series/parallel. That is the configuration on our sailboat and that life is a LOT harder on a battery than in a motorhome. Shore power at anchor???? I agree, there are more quality deep cycle 6 VDC batteries than 12 VDC, but there ARE 12 VDC batteries that are every bit as good. Share this post Link to post Share on other sites
kaypsmith Report post Posted September 3, 2016 I use 3 12 volt dc batteries in parallel for my 12 volt supply in my coach, have worked very well. Share this post Link to post Share on other sites
tbutler Report post Posted September 3, 2016 We've been running our residential refrigerator on 4 6V batteries since we installed it in 2010. I replaced the regular wet cells in 2014 with AGM, still 4 x 6V. We have auto gen start but it is a convenience, not a necessity. When we are without electric and living in, using the coach we simply run the generator in the morning for coffee, etc. A couple of hours in the evening and it will last overnight unless the weather is really cold and the furnace runs too much at night. That might involve running the generator sometime in early morning for several hours. Going to more than 4 6V batteries would be nice but I don't see it as a necessity in our case. Share this post Link to post Share on other sites
dickandlois Report post Posted September 4, 2016 On 9/3/2016 at 8:44 PM, abyrd said: I just installed residential refrigeration and I have been looking in installing auto-start for my generator. I have a Magnum inverter/charger and have found that the residential refrigerator is requiring 10 amps from coach batteries for normal operation. I only have 4 Interstate 6 volt golf cart batteries and have not experienced any problems going for a couple of days without running the generator or traveling down the road. The auto generator auto-start feature can be added to the Magnum inverter/charger for a couple hundred $ VS $600-$700 to installing the ONAN auto-start. Jim Jim, the Onan Auto start system has been problematic, so you might want to do some research. Depending on the Magnum unit you have. You might be able to add AGS mod to the existing system. Rich. Share this post Link to post Share on other sites
BillAdams Report post Posted September 4, 2016 It's all about amp hours (AH). Add up the total number of amp hours that your 4 - 6V batteries contain and then divide by 2. Then add up the amp hours that the 3 12V batteries and you have know if you will have more or less total amp hours available for use. Your existing inverter/charge should handle the charging requirements of either set of batteries. Let us know what you find and what you do. Share this post Link to post Share on other sites
sidney.shafer Report post Posted September 9, 2016 Have two 12 V house batteries in our 2013 Itasca. Having trouble keeping them charged between camping trips. How can I determine if our Xantec inverter/charger is charging properly? Is it okay to use a separate battery charger to charge the house batteries without disconnecting the battery cables? Share this post Link to post Share on other sites
wolfe10 Report post Posted September 9, 2016 Sidney, Welcome to the FMCA Forum. Yes, when stored with shore power on, your Xantrex inverter/charger should keep the house battery bank charged. And, check with Winnebago, as on some coaches, it will also charge the chassis battery. To verify is pretty easy: with a digital voltmeter (they start under $20 and are a must for any RV), ASSUMING that the inverter/charger has been properly programmed (easy instructions in your Xantrex owners manual-- usually just using your remote panel you should be reading 13.2-13.5 VDC at the house batteries. When you just plug in, voltage will be higher (13.8-14.2 VDC) but tapers off as the charger section reaches float level. You can also check the chassis batteries voltage to determine if a separate smart charger is needed. Do NOT use a standard automotive charger long term, as they can overcharge the batteries and destroy them. Share this post Link to post Share on other sites
five Report post Posted September 10, 2016 7 hours ago, wolfe10 said: .... Do NOT use a standard automotive charger long term, as they can overcharge the batteries and destroy them... As usual, lots of good advice from Brett. Point of clarification on the chargers. Get one that will automatically shut off when the batteries are fully charged...then it won't damage them. Share this post Link to post Share on other sites
sidney.shafer Report post Posted September 10, 2016 Brett & Five, Appreciate the responses. Our Xantrex 1000 unit does charge the chassis and house batteries, and appears to be working since the readings for both were 13.4 VDC when being charged. When I disconnected shore power, both dropped to 13.1 VDC, and 2 hours later the chassis read 12.8, but the house was only 12.1 VDC. I haven't used the automotive charger yet, but need to confirm that I can connect it without disconnecting the battery cables. My charger reduces the rate of charge as the battery is charged. I checked all cells with an hydrometer, and the readings were a little below 1225. Appreciate your advice; my gut tells me I need new house batteries. Sid Share this post Link to post Share on other sites
wolfe10 Report post Posted September 10, 2016 Sid, If all cells in the house bank read about the same, before replacing, let the Xantrex inverter/charger charge them at least overnight and re-read hydrometer readings. Hydrometer readings that are all low but close to each other can indicate a "not fully charged battery" as well as a bad one. Though it can happen, normally one cell dies first, not all at the same time. So, decide tomorrow (if plugged in overnight now) whether to invest in new batteries. Share this post Link to post Share on other sites
sidney.shafer Report post Posted September 10, 2016 Brett, All of the cells do read about the same. They had all been pretty low, so topped them off with quite a bit of distilled water, maybe should have used an electrolyte liquid to fill them. Have you ever tried AGM vs wet cell for the house? Currently have a NAPA group 31 deep cycle. Sid Share this post Link to post Share on other sites
wolfe10 Report post Posted September 10, 2016 Sid, Were the plates exposed? If so, good chance they are toast. Yes, have used AGM's for house batteries in our last 3 sailboats as well as motorhomes. More expensive than wet cells, but a good, maintenance-free choice. Make sure to re-program your inverter/charger when you change battery technologies. Share this post Link to post Share on other sites
sidney.shafer Report post Posted September 10, 2016 24 minutes ago, wolfe10 said: Sid, Were the plates exposed? If so, good chance they are toast. Yes, have used AGM's for house batteries in our last 3 sailboats as well as motorhomes. More expensive than wet cells, but a good, maintenance-free choice. Make sure to re-program your inverter/charger when you change battery technologies. Brett, All of the cells do read about the same. They had all been pretty low, so topped them off with quite a bit of distilled water, maybe should have used an electrolyte liquid to fill them. Have you ever tried AGM vs wet cell for the house? Currently have a NAPA group 31 deep cycle. Sid Brett, Yes, several cells had plates exposed. Guess it's time to go shopping. ? Will take a look at AGMs. Share this post Link to post Share on other sites
sidney.shafer Report post Posted September 10, 2016 Brett, Follow up. The chassis battery is also a wet cell, and it is fine, but since the inverter/charger charges the house and chassis batteries, do I need to replace the chassis battery if I switch to AGM? Sid Share this post Link to post Share on other sites
wolfe10 Report post Posted September 10, 2016 The charging curves for AGM and wet cell are close enough, were you to change to AGM's for house, set the charging program to AGM. Wet cell starting batteries will be OK. Share this post Link to post Share on other sites
sidney.shafer Report post Posted September 10, 2016 Thanks again Brett for the expert advice. Time to go shopping.. Sid Share this post Link to post Share on other sites
hermanmullins Report post Posted September 11, 2016 Just heard today about how to charge an AGM battery that is completely discharged. From what I understand you can not charge one that is completely discharged. Was told that you have to fool the Battery. What you do is put a fully charged wet cell battery in parallel with the AGM and connect the charger to the wet cell battery. Was told that the charger will then rejuvenate the AGM. Will it work or just an ole wives tell, I don't know. However as I have said before, "It would be like giving Chicken Soup to a dead man. It may not help but it can't hurt". Herman Share this post Link to post Share on other sites
manholt Report post Posted September 11, 2016 When I went from wet to AGM last month, the Magnums automatically reprogrammed themselves....Got to thinking about that, so I called tech at AC...My coach came with all AGM's in 2010. First owner, changed all to wet, for whatever reason, and did not re program! 2, 12V for chassis and 8, 6V for house, with 2 Magnum 2800 Inverter/Charger. No more blinking lights and pads, no clunks in the night.... Carl Share this post Link to post Share on other sites
wolfe10 Report post Posted September 11, 2016 Herman, Not aware of a problem charging a dead AGM-- at least from the battery end of it. If there is, would like to see a link to documentation on it. But, many chargers, if sensing a dead battery will NOT begin the charge cycle. So, yes, I have had to use a cheap ("not smart) automotive charger to start the charging process-- not on our coach but on a neighbors. Share this post Link to post Share on other sites
dickandlois Report post Posted September 11, 2016 Yep, Charging batteries is one of the hardest items to get right IMHO. As mentioned by Brett, charging a Dead or highly discharged AGM battery requires the use of a low current charger to start the process, since heat will kill them by displacing the water. Another affect of heat on AGM batteries is the ambient storage temperature. The higher the temperature the shorter the life cycle. Where as wet cells can last up to 20 years with good maintenance. The fallowing link might help and the are some hyper links with in the information, but it can be confusing along with informative. http://batteryuniversity.com/learn/article/how_heat_and_harsh_loading_reduces_battery_life Rich. Share this post Link to post Share on other sites
five Report post Posted September 11, 2016 It's pretty bad when we have to try to outsmart a battery. Last week I got a new charger to carry in the MH if I ever need it for one reason or another. It says it can handle all types of batteries...AGM, GEL and wet cell. I just have to press the correct button...AGM in my case. Share this post Link to post Share on other sites
hermanmullins Report post Posted September 12, 2016 Gentlemen, Thanks for clearing this up. As I said, I have no knowledge or facts on the AGM Batteries. I am still in the Stone Age with batteries, aka wet cell. If I understand, you need to trickle charge the AGMs to being them back from being completely drained. Herman Share this post Link to post Share on other sites
