Larry D. asked a question about charging voltage that has been asked a lot. His question:
Brad, a battery charger question please. I have a Magnetek 7200 Charger/Converter in our 1993 Winnebago. Have you ever heard of the charging voltage increasing to 16.8 volts as the battery approaches full charge? I am not sure if this is normal or not or if the regulator is the problem? I have just replaced two size 27 old batteries that gassed and boiled out (which almost overcame me with H2S as I slept). I replaced it with one group 29 battery that also gassed and boiled on the first cycle.
Brad: OK Larry, there is more to your question that I will address in a minute but lets take this part first. The problem is not the battery. The problem is in your charging device. All chargers are supposed to have a voltage high end limiting device in them to control the battery charge. In a 12 volt system that limit is usually around the 14.4 volt range. However my solar system will charge to 15.3 volts and then top off there. 16.8 volts is way too high and the charger needs service or replacement. Now to the second part of your question.
Larry D.
With no battery connected and the Converter/Charger on I turned on my radio. It commenced to crackle and then smoke came out of it. Would you believe that when I measured the voltage it was 43 volts?
Brad: First of all a unit should never be run with the battery disconnected. The battery acts as an absorber for the current that the unit will put out. The unit should havecaught the increase in voltage and throttled back the output voltage, just another indication that the unit is defective. Since Magnetek is no longer available a search for another brand is in order. With the voltage regulator out to lunch and no battery in the circuit to absorb the energy the voltage will spike to the maximum that the unit will put out. Then when you turned on the radio you were lucky that it was only smoke that you got. The battery will offer more resistance to the flow of current, amps, as the level of charge of the battery increases. When the voltage regulator in the charging unit is working properly it will limit the voltage flow as the battery voltage opposes the charging units voltage flow controlling the charge rate.
Big T sent in the following comment and question: I have an Alfa SeYa 2004 and have a lot of corrosion around my batteries while in storage. I thought my solar panels were over-producing so I disconnected them but the problem persists. I clean them regularly with baking soda and water but it continues to build up. I’ve now had to replace the wiring harness as the corrosion has made them brittle and destroyed the wiring links to the battery terminals. The corrosion is also eating into the steel mounting cages. Do you have a remedy or suggestion as to what i can do to fix this situation?
Brad: It kinda sounds like your batteries might be getting a little old and tired. If the coach is a 2004 and the batteries are the original ones, they could be actually 2003 production. Most times the chassis is close to a year old when they start building the coach on it. I would suggest load testing the batteries with a commercial load tester. If they are close to the lower acceptable level then they will gas more than a battery that wil accept a charge better. Secondly, cleaning is good but it has been my experience that unless you coat and seal the metal it will continue to corroded. There is a paint on the market called POR-15, Google it, that will seal the metal and stop the corrosion. When I built the battery box for my big battery pack I made it out of wood because I did not want the corrosion problem. But I would check the voltage output of the solar system, the converter/charger, and alternator. None of the units should show more than 15.3 volts at the battery.
Remember I like to answer comments on the chassis, engine and power train, and electrical systems. So, more next time stay tuned.
Brad
Good Sam Camping
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Anonymous
Can you come help me with my 1994 Winnebago Vectra electrical. I was given this rv and it had been sitting in beach weather for ten years. 25,000 miles and the engine turned over with assist jump. Got three new batteries. Now the carriage batteries are drained and when my “help” incorrectly tried to plug in the shore power there was a noise from the converter area and I believe it no longer works. Although I have read a bunch of manuals I guess my main problem is how to hook up outside power. This shoreline comes with a fifty amp end and two different adapters when put on it make a regular household outlet plug. The place where I’m permanently parking accommodated my 86Ralleye fine. The fifty to 30 amp thing confuses me. Just come to the sunny central coast of California and I will make you dinners!! Thanks Linda
Joe L.
Your comment that charger voltage of 16.8 is way too high seems to be at odds with some charger manufacturers. I recently installed a ProSine series inverter / charger in my Class A wihch has an equalize function. Admittedly, it is a maintenance function that has to be separately activated which applies a low, monitored current with as much as 17 volts charge to a fully charged set of batteries for a period of time determined either by a reduction of the batteries voltage rise or a user set timeout which can be up to several hours. It is claimed that this restores the plates to full potential and if used properly and in the appropriate interval for your utlization schedule, can extend the life of a set of batteries by many fold. It is recommended that the batteries are closely monitored during this process but might be needed as much as once a month on a heavily used set of batteries. Can I assume that your comment re 16.8 volts being too high is directed at only normal charging cycles, not maintenance ones?
Pete Soots
I had my converter/charger replaced last year and the info sheet with it says you can disconnect the battery with no problem. It is a parallax brand. Who or what is right? I want to use a ” battery minder” unit for charging ,but am concerned about what affect it will have with both chargers connected.. I would like to just use the battery disconnect switch to remove the battery from the converter charger. I asked the battery minder people about this and they said to disconnect the battery from the converter and let the batteryminder unit do the charging. What do you think is the correct way to do this?
RV LAD
THANKS BRAD FOR CONFIRMING MY SUSPISION OF A BAD VOLTAGE REGULATOR IN MY CONVERTER/CHARGER. GUESS I WAS HOPING YOU’D FIND A SIMPLER—CHEAPER SOLUTION SINCE I RESEARCHED DEFUNKED MAGNETIC AND FOUND PARALLAX TOOK THEM OVER AND SELLS AN EQUIVALENT TAPER CHARGER FOR $385. YOU GIVE VERY GOOD ADVICE TOO ABOUT NOT OPERATING THE UNIT WITHOUT A BATTERY, DESPITE MAGNETICS CLAIM THAT THIS IS OK TO DO. I DID KNOW BETTER—-ONE OF MY STUPID SENIOR MOMENTS. THANKS AGAIN—APPRECIATE YOUR EXPERTISE.
LARRY D.
Darthvagrant
In reference to “road handling”, I might add my $.02 worth. My class A Coachmen which has so much overhang behind the rear axle it wouldn’t pass European specs. Too bad the DOT isn’t on the ball on all these coaches that have the rear axle nearly in the center of the unit. Europe won’t allow that crappy ‘overhang ‘ design to even be sold. The manufacturers are too cheap to go th the expense of extending the wheel base rather than just extending the frame. Yeah-I know. That increases turrning radius, but at least a better handling coach can be built. I laugh when I see a mickey-mouse “tag axle” on gas class As and Cs with the drive axle in the center of the coach. Sort of like getting crutches because of a rock in your shoe.
.
I often allude to my Coachmen class A taking steering suggestions. Driving (particularly in a cross-wind) I sort of suggest where I want it to go. Ford put a power steering cooler on for a reason. The P/S pump is working its a$$ off just keeping the coach on the road. Thank goodness for the currently wider road lanes. I need all I can get.
Nick Tsakires
I have subsribed to the blog.When I go to read an article on my browser I get a “suscribe to” window that will not go away.
The window is larger than the sceen, and will not move by thr cusor to ‘X’ out if available.
I am using the newest version of Firefox.
If there is not an easy/qiuck fix I shall unsusribe.
george mullins
brad hit it on the nail on the ehad when he spoke of trying to use a coverter with no battery, it can also hurt the charge/converter not haing it hooked up to a battery as well. i have seen this happen to many folks who winter in quartzsite in an rv park, they disconnect the batteries thinking the converter will carry the load and end up with blown appliances from excessive voltage. thanks brad for bringing it out in the open. mike
Phil Hooper
I have a 2005 Damon Ultrasport on a Freightliner chassis. I bought it from a dealer in 2007, and from the very first trip I noticed that it seemed to have a steering wander. I constantly have to move the wheel back and forth, not very much, but enough to be annoying.
The selling dealer couldn’t notice the problem, so they took it to Orlando Freightliner who also couldn’t see a problem. I took it to my own rv shop who also couldn’t notice anything with the steering, but a bus place I took it to to get a balance and alignment said the problem was so bad that it was dangerous but couldn’t find a cause. I then took it to Ocala Freightliner who also couldn’t notice anything amiss, but did check all steering components and ride height without finding anything needing adjustment..
I certainly don’t feel that the problem is a danger, but the constant minor steering changes spoils what would otherwise be a pleasant ride in an otherwise fine coach. I’ve heard since that it might be a bell crank problem, but don’t know how to go about checking that.
Any suggestions?
Phil