overcharging battery

[mechanic1]

hello to all
bought this motorhome in may of this year . its a 1977 ford e 350 chassie, don,t know who built living quarters still trying to find that one out but thats another story. it has a battery isolator which seems to be doin it,s job. however when i bought it the guy told me he put a new battery in for the motor home lights and whatever else it runs . we were rarin to take her out no problems plugged her in at the camp site everything good.had it out several times after that . evertime i would bring it home we would plug it in to house current.to run the vac and whatever . well we had to cut grass . so we unplugged my son gets in the motorhome turns on the lights nothing . iam thinkin battery went dead . well i take the battery out take it to my shop was gonna hook it up to the charger . i pull the battery caps and guess what ? no battery acid . i fill each cell up with new acid and recharge . hook the battery tester to it it says replace battery. i look on the side of the battery and its a wal mart battery took it up there and they replaced it free of charge. god i love that walmart warrenty. anyhow put the new battery back in everything lit up . iam thinking were good went campin a couple more times pluged it in every return trip and she cooked another battery. could this inverter in this thing be bad or is it the age of it that it dosn,t know to stop charging orignal inverter . it has two batteries one in the engine bay the other in the rear of the motorhome when the rear goes dead the truck will start right up thanks dave sr

[RedneckExpress]

The old stock converter/chargers that came in most RVs, even today, are junk. You need to replace the existing charging unit in your power panel to either a Progressive Dynamics, or WFCO 3 stage automatic converter/charger.

You can get the best deals on them at BestConverter - Converters, Inverters, Electrical Supplies, Electronics Randy will be more than happy to answer any questions you have.

Btw, and Inverter and Converter are two different critters. An Inverter takes 12 volt and makes 110 AC, a Converter takes 110 AC and makes 12 volt.

[wa8yxm]

I partially agree with RedneckExpress... Many older rigs came with a single stage converter that either never fully charges the battery or seriously over charges them.. Usually the latter

Now, where i disagree with him is on today's rigs.. Many today (I do not know about all) have decent converters.. Mine came with a Progressive Dynamics Intella-POwer 9180 with charge wizard and better than that.. It very simply does not get (As good, yes, better no)

Suggestion: Many RVers feel (As do I) that an inverter is a handy dandy device, This lets wife microwave dinner in the abscence of shore or generator power, it means we can watch TV, in side the "house" after quiet hours when boondocking and it runs the sat receiver and the "in-motion" antenna when driving so the DVR's (Also run by it) can record the wife's daytime drama shows.

The one I have is an Xantrex Prosine 2.0.. Kind of expensive, but worth it.. and this unit also has a bulit in power transfer switch and charger for the batteries.

Like the PDI 9180 with wizard.. It is a top of the line and once again, they simply do not make better... (As I said, AS good as it gets, better, no) I will add there are several both inverter/chargers and converters that are at the top of the list.. not just these two

[Marty too]

With all due respect to the above posters, I will disagree to some extent about the old converters. Now if you have the coins to do so, sure swap the thing out for a newer one but if that isn’t an option and depending on the make and model to what you have it might be adjustable to give you the service you want. Let me add here, I went through this problem of cooking my coach battery on a 94 motor home until I got smart and started researching the properties of wet cell batteries. What I learned and this applies to most any 12 volt battery, the maintenance voltage on a fully charged battery should not ever exceed 13.8 VDC. So this should be the first step in checking your battery. If it’s 13.9 or better, yep, eventually it’ll start cooking. So try this------

1. If you have a digital volt meter (and if not get one even for future use and Radio Shacks have them at a reasonable price) with shore power applied, measure across the terminals of a fully charged battery. Correct reading should be between 13.4 and 13.8 VDC. If it’s greater then 13.8, kill all shore power and go to the next step.

2. Determine what the Make and Model that is the converter. (Most converters are located under the refrigerator as a part of the fuse/circuit breaker box. (If not, locate it if possible.) Should it be a Magnetic(?) 6300, it’s probably adjustable. If so-----next step.

3. If it’s a 6300, pull the face plate off so you can look inside behind the fuse/CB panel. Look down to the lower right side of the open box to see if there is a vertical placed circuit board there. If so, look very carefully to see if there is a adjustable part about the diameter size of a nickel. If so, that part will or should adjust the output voltage of the converter.

4. Now things might be a bit “hairy” only if your not careful. To adjust that “pot” to lower the voltage will need a long shank common screw driver of some type. If the screwdriver shank is metal, wrap it with tape for safety reason. With shore power back on and with a digital voltmeter across the battery terminals, adjust that pot counter clockwise to lower the output voltage. When I did mine, I lowered the voltage to 13.7 VDC. Keep an eye on the voltage across the battery, should it increase, readjust that pot. The whole idea is to try to get the voltage to 13.7 or even a bit less and try to keep it there over a period of time. I let mine set for about 3 hours and when it stabilized at 13.75, I called that good.

I never had coach battery problems after I went through all of this even up to the day (maybe three years or more) when I traded from a 94 to the 05 I have now. There’s another little trick I pulled while I had that box open. Back in the right corner of the box was a cooling fan. I noted in and around it, it was filthy with dirt, dust and what ever so I pulled the motor out and vacuum that area out as well as much of the box I could. Out of curiosity, I applied 12 Volts to the motor to see if it would still work and felt the air that it was pushing across the back of the box. Didn’t seem like much so for the fun of it, pulled the fan off the shaft and turned it around. It didn’t change the rotation of the fan blades but it did change the amount of air that it was pushing out. Guess it was all in the designed of the blades but I left them as is when I reinstalled that motor. That made a difference in the operation of the converter especially at night when very little pull was placed on the converter. I could hear that cooling fan run off and on all night long.

Marty

[RedneckExpress]

Originally Posted by wa8yxm

I partially agree with RedneckExpress... Many older rigs came with a single stage converter that either never fully charges the battery or seriously over charges them.. Usually the latter

Now, where i disagree with him is on today's rigs.. Many today (I do not know about all) have decent converters.. Mine came with a Progressive Dynamics Intella-POwer 9180 with charge wizard and better than that.. It very simply does not get (As good, yes, better no)

Suggestion: Many RVers feel (As do I) that an inverter is a handy dandy device, This lets wife microwave dinner in the abscence of shore or generator power, it means we can watch TV, in side the "house" after quiet hours when boondocking and it runs the sat receiver and the "in-motion" antenna when driving so the DVR's (Also run by it) can record the wife's daytime drama shows.

The one I have is an Xantrex Prosine 2.0.. Kind of expensive, but worth it.. and this unit also has a bulit in power transfer switch and charger for the batteries.

Like the PDI 9180 with wizard.. It is a top of the line and once again, they simply do not make better... (As I said, AS good as it gets, better, no) I will add there are several both inverter/chargers and converters that are at the top of the list.. not just these two

Lance, Thor, Fleetwood, Terry, Forest River, Pastime, and many others, all used Magnetek (aka Magnajunk) or Centurion converters well into the 2000s. These converters were welll known for boiling batteries. Only a few of the higher priced manufacturers have switched to putting PDs or other 3 stage converters in their units stock.

[mechanic1]

hello agian
thank you for all your input.however let me give you a little more detail things i didn,t mention on the first post. this converter is apparently only designed for two things charging the battery and the coach lights. when iam unplugged i have no juice to my 110 outlets frig is two way 110 and propane. hot water heater is propane only furnace will run on battery power at least when i turn the switch on you can hear the blower come on. iam gonna bring my meter home from work and measure across the battery i,ll let you know what i come up with when its plugged in , another thing the battery isolater under the hood its supposed to send a charge to the batteries while your on the road as far as i know its doin its job. it,s never drained the truck battery and we always have plenty of juice. now iam not an electrical wiz but it seems to me with this thing pluuged in it should charge the battery till it,s topped of and then cut back or shut off. i may be wrong . it would be like me takin your auto or pickup truck taking it to my shop and charging the battery none stop for a week .something is gonna give . like i said maybe its the age of the thing after all it is a 1977 model maybe it just finally craped out. i couldn,t see unhooking the battery lead everytime you want to plug in to shore power . or maybe this thing had a kill switch on it and someone took it off . see what your thoughts are on this . thanks dave sr

[wa8yxm]

What you are describing there is 100% normal. NO converter provides 120vac when you are not plugged in and the generator is not running (IN fact it does not provide it when you are plugged in or have the generator runnign)

The converter converts (hence it's name) 120vac to 12vdc

INVERTERs do the Inverse.. that is they converte 12vdc to 120vac

Generally.. inverters are optional.. very optional.

Again we need the make and model of the converter. as others have said, many coaches epically older ones. come with Magnajunk (Thought I coined that name RedNeck), Though as I said, many now come with decent converters.. Redneck describes the Magnajunk jobs as well as I can, if not better, so I'll leave his discription stand.

But for many years that was the standard converter, or another like it.

As to the price of a converter upgrade... Price a new set of batteries.. If you can double the life of the batteries.... The upgrade will very likely save you money, making it's cost negative.. and a good converter, good batteries can last a decade instead of a season.

Now, as to charging the chassis battery.. Some coaches come with dual/dual charge systems, these whatever charging source (Converter or alternator) charges both house and chassis batteries (Lots of techinical stuff left out here)

If yours does not do this then there are a couple of products you need to investigate and, perhaps install.. Install is very simple, 3 wires,, Just 3 wires Chassis HOT, House HOT, Ground, hook up next to the isolator

Higher priced: Xantrex Echo Charge
Lower Priced: Trick-L-Start

Other than price, I'm not aware of any differences, but I do not have them for test/inspection (I have a Intelletec Battery control system which is bi-directional and kind of "Smart" about it too)