Community Forums

Old Scout · 07-15-2017, 08:25 AM

For many of the last 14 years, we have had to store our 2003 "off the grid." Recently upgrade power to the barn--so life is good. Question--always understood battery bank was fully charged if around 12.6 or 12.7 volts [at rest]. After watching my Xantrex RS2000 inverter [3-stage charger] maintain the bats at around 13.4 volts in "float" for last 4-5 months, I am wondering if this level is too high? Recently, changed out batteries with new Trojans so no symptoms of over-charging [eg, water use, evap leaks, etc.] Thoughts?????

wardy · 07-15-2017, 08:38 AM

Battery Maintenance | Trojan Battery Company

You're charger is doing fine. But after a period of storage you may want to set the charger to the "equalize" mode to reduce any stratification of the electrolyte. You should get many years out of those Trojans.

Old Scout · 07-15-2017, 09:30 AM

Thanks Wardy--confirms what I kind of thought I knew. Great link to Trojan website--immediately saved it to my favorites.......

vsheetz · 07-15-2017, 11:25 AM

That's ok. Check Trojan battery spec sheet for their charging recomnendation.

wolfe10 · 07-15-2017, 01:09 PM

13.4 is a little on the high side for the ambient temperatures you are experiencing in the San Antonio area (high). In July Texas temps I would rather see in the low 13's.

Do you have a temperature sensor on your inverter charger/battery? Look at the inverter end for the telephone-type small plug.

If, so, try disconnecting and manually reprogramming inverter/charger for "warm, wet". OR make sure the sensor is on the warmest battery post in your house bank.

How much water are you using?

Brett

RVPioneer · 07-15-2017, 01:54 PM

13.4-13.5V is perfect. 12.6V is the low end of a healthy battery, at this voltage the charger should be charging. Oddly enough at 12V a 12V battery is rapidly approaching being a dead battery. At 11.5-11.8V you'll be reaching for the battery boost switch to get the engine started.

A fairly simple and relatively low cost solution to keeping the chassis batteries charged in an off grid storage situation is a 20w solar panel and charge controller. Works best in sunny locations and the chassis batteries need to be disconnected at the switch. At least on a 2005 with the VMM's using power. If garaged (or barned, for that matter) the panel can be located outside the building. Wiring in an input connector in the battery compartment would allow for both a roof mounted panel or separate panel to be used remotely.

Not truly necessary with electricity available. It is a good back up system in the event of a power outage.

rrthor · 07-15-2017, 05:40 PM

My float stage voltage level is 13.4 volts. The manufacturer of my inverter calls the charger a 4 stage charger. It has the bulk, absorb, and float stages and then it has a "full charge" stage. In this stage after four hours of float charging the charger turns off. When the batteries drop below 12.7 volts the charger initiates another four hours of the float stage.

I have been very happy with the charging algorithm of this inverter. I have not had to add any water to my batteries in the last year. My coach is plugged into shore power nearly all the time.

Old Scout · 07-15-2017, 09:10 PM

Wow--a 4-stage charger--sounds like a great inverter/charger unit--might you share the brand name with us?????

rrthor · 07-15-2017, 10:45 PM

Dean it is a Magnum MS 2012. Magnum calls this 4th stage "Battery Saver Mode". Magnum defines this 4th stage as follows. " Full charge stage is designed to keep batteries fully charged over long periods of time and prevent excessive loss of water in flooded batteries or drying out of agm/gel batteries". Whether it is or is not an actual 4 stage charger might be a claim by Magnum's marketing department. I have been very satisfied with the performance of this inverter's charger.

wolfe10 · 07-16-2017, 06:32 AM

Correct charge and particularly float voltage is very temperature dependent.

I totally agree 13.4 is perfect for "human comfortable" temperatures. Too low if around freezing and just a little high if at 90 degrees F.

That is why temperature is one of the programmable features of most inverter/chargers and many have temperature probes. Yes, that means if you don't have the temperature probe you do need to re-program the temperature feature as the seasons change.

AKOne · 07-16-2017, 12:13 PM

Have a Samlex EVO-2212 in my coach: Samlex America -- Products.
It will automatically adjust Float charging current to compensate for high or low ambient temps. If batteries are in Float stage for more than 10 days, the unit will automatically cycle through a full charging sequence. Samlex uses a dynamic algorithm for all charging stages. Simply put, the length of all charging stages is determined by the batteries state of charge. The software on newer inverter/chargers has become quite sophisticated. Like other inverter/chargers all parameters may be manually programed. Because of the cold winter temperatures in Alaska, a constant float charge is best to prevent freezing. In addition, regardless of the season, I know my battery bank is always at 100% when it is time to hit the road. A fourth stage of charging is commonly referred to Equalization. Labeling a fourth stage as a maintenance stage can be confusing. Unless your RS2000 is having issues, swapping it out should not be necessary. Unless, you are simply itching to upgrade to the latest and greatest.