Electrical question February 20, 2003, 01:01:52 am Yahoo Message Number: 19139Just let me start by saying I've read most of the topics on this site about the 12V system, and they leave my head spinning.That said, I hope someone might be able to help. My 6V batteries were 10 years old, so I decided to replace them. When fully charged, it didn't take running the furnace long, and the display panel inside was down to "good". I took the rig to Camping World (another story) and had them replace the batteries, and install an LP detector. When I got home and checked the display, the batteries showed "good". I called Camping World, and they said that was because I needed to give the batteries a good charge. So, I plugged the rig in for a couple of days. Didn't use it again until this past weekend. We stayed at a park with A/C. On the way home the fridge was shut off. I just checked the display while unpacking, and it said "good". This was with everything shut off, except the LP detector. Shouldn't I be getting a reading of "charged"? Do you think the batteries I purchased were defective, or that Camping World wired something incorrectly when they installed the LP detector? With the 10 year old batteries I would get a reading of "charged" at least for a little while before it dipped.I feel I should call Camping World, but I doubt they would have a clue. I know enough not to go back there again.Thanks, Laurie
Re: Electrical question Reply #1 – February 20, 2003, 07:01:57 am Yahoo Message Number: 19140With the 10 year old batteries I Quotewould get a reading of "charged" at least for a little while before it dipped. Thanks, Laurie Hi Laurie:You are misinterpretating the readout. The high indication is not "charged" but "charging". When you charge a battery, you are placing between 13.7 to about 14.5 volts on it, and when the charge is done, the batteries hold this voltage for a short time and then slowly diddipate it down to a fully charged resting voltage of about 12.65 volts. You indications were normal, "charging" when it was charging and then "good" when it finished. Your old batteries had lost capacity; but your new ones are giving you the correct readings.If you want a good tutorial on batteries and 12 volt systems (and everything wlse RV related) see www dot phrannie dot org.Happy trouble free trailsGus Weber
Re: Electrical question Reply #2 – February 20, 2003, 09:53:09 am Yahoo Message Number: 19146Laurie, It shouldn't take long to go from the charge indication to the good regardless of what is being powered. "Good" means the batteries are just that, they are at a good charge level. If it took it down to fair rather quickly then that would be cause for concern and an indication the batteries are no longer holding a charge for long and need replacing. I know of several people that have gotten 12+ years from Trojan T-105 batteries. The only way to know what the actually condition of the batteries is to have a voltage reading either with a multi-meter or in the case of having a solar charge controller with a digital readout using that. The charge position on the panel means that the batteries are fully charged at over 13v and it only stays in that state or position for a very short time.I don't know about Gus' panel but the ones I've seen didn't read charged or charging just simply Charge, Good, Fair, and Weak, some may say charged or charging depending on the mfg. The solar charge panel does read charging when it is charging and depending on the switch position the battery voltage, charge amps, etc. The batteries are typically in a decent useful range until the panel reads weak when nothing is drawing power and they are "resting". With a meter and no draw of any kind "phantom" or otherwise when at the weak level they will typically be under 12.5v, at fair around 12.5v, and at good 12.6v or more but you can only know for sure by having some type of meter to test them with no load. The voltage shown on a meter when something is drawing power will be less than those in a resting state meaning with a load of any kind.As Gus mentioned the Poop Sheets by Phred have good explanations of this and many other topics and you should "bookmark" that web site for future reference. http://www.phrannie.org/phredex.html Mike
Re: Electrical question Reply #3 – February 20, 2003, 10:18:37 am Yahoo Message Number: 19148QuoteJust let me start by saying I've read most of the topics on this site about the 12V system, and they leave my head spinning. The reading on the panel indicator is only a crude interpretation of battery condition. Since operating the systems in a m'home is akin to living in a cabin in the backwoods 'off the grid', learning a bit more about some of the resources in the m'home can go a long way toward improving your peace of mind. A digital voltmater (or multimeter) is a very useful tool, and pretty easy to use. If you want to get one (e.g. from Radio Shack), you will find lots of folks here can bring you up to speed on how to use it. In this case, becoming familiar with the readings you will get directly at the battery teminals and elsewhere will help track down potential problems, and also help to interpret the panel readings.Steve
Multimeters- Was Elec ? Reply #4 – February 20, 2003, 01:57:57 pm Yahoo Message Number: 19164QuoteA digital voltmater (or multimeter) is a very useful tool, and pretty easy to use. If you want to get one (e.g. from Radio Shack), you will find lots of folks here can bring you up to speed on how to use it. Steve OK, Folks, I'm ready to be "brought up to speed" -- Received one for my BD (a Radio Shack model -- it was on my tool box wish list), but Im embarrassed to admit I don't know about its uses or how to use one. Bring on the info, and mucho thanks again! Lorna
Re: Multimeters- Was Elec ? Reply #5 – February 20, 2003, 02:26:21 pm Yahoo Message Number: 19171QuoteOK, Folks, I'm ready to be "brought up to speed" -- Received one for my BD (a Radio Shack model -- it was on my tool box wish list), but Im embarrassed to admit I don't know about its uses or how to use one. Bring on the info, and mucho thanks again! Lorna Lorna, which model do you have?Steve
Re: Electrical question Reply #6 – February 20, 2003, 02:33:48 pm Yahoo Message Number: 19173QuoteA digital voltmater (or multimeter) is a very useful tool, and pretty easy to use. If you want to get one (e.g. from Radio Shack), you will find lots of folks here can bring you up to speed on how to use it. In this case, becoming familiar with the readings you will get directly at the battery teminals and elsewhere will help track down potential problems, and also help to interpret the panel readings.Steve Thanks all of you for putting my mind at ease. I will have to get a voltmeter so I can better tell what I am looking at.Laurie
Re: Multimeters- Was Elec ? Reply #7 – February 20, 2003, 02:37:09 pm Yahoo Message Number: 19175which model do you have?Quote Steve Steve, it's a "Pocket Size 18-Range Digital Multimeter." Says it's a 3-3/4 digit display that can show up to 3,200 units; measures AC and DC voltage up to 500 V each and resistance up to 30 M .. which translated, means?!! Lorna
Re: Multimeters- Was Elec ? Reply #8 – February 20, 2003, 08:21:58 pm Yahoo Message Number: 19190QuoteOK, Folks, I'm ready to be "brought up to speed" -- Received one for my BD (a Radio Shack model -- it was on my tool box wish list), but Im embarrassed to admit I don't know about its uses or how to use one. Bring on the info, and mucho thanks again! Lorna Hi LornaFirst, you need a place to read the voltage. I used to open the electrical panel until I discovered that the 12V recharge cord for Norelco shavers plugged into my COACH (not cigarette lighter or other chassis battery socket) socket and the two tiny holes that normally go into the shaver fit my probes perfectly. It is not necessary to get the positive (red) voltmeter lead into the positive hole - the meter will just read the same voltage as negative. Second, you need to move the meter switch to DC. It will tell you the voltage to two decimal places. When done, remember to turn the meter off.Now you need to know what voltage means what state of charge in the batteries. But before you read the voltage, make sure you have not been charging for a few hours. The batteries hold on to this higher voltage for a bit, depending on their load.Now you need to make sure that you are reading NO-LOAD voltage. If you have a light on, it will decrease the voltage and give you a wrong indication, too low in voltage. Don't worry about the propane detector and water pump switch - they do not add a significant load.Once you have the no-load voltage, you need to know what voltage equals what charge. Use this table:State of Charge Volts 100% 12.7 90% 12.5 80% 12.42 70% 12.32 60% 12.20 50% 12.06 40% 11.9 30% 11.75 20% 11.58 10% 11.31 0% 10.5 Thus if you no-load voltage is 12.47, your state of charge is about 85%.Make sense?Happy trailsGus Weber
Re: Multimeters- Was Elec ? Reply #9 – February 20, 2003, 09:40:08 pm Yahoo Message Number: 19193QuoteMake sense? Happy trails Gus Weber Gus, I'm sure it will make sense when I can physically practice with your instructions in front of me....I printed them out and stapled them to the RadioShack instructions (written in Greek or is that GeekSpeak?!!) I'll probably laminate the table and post it in the battery compartment -- seems like essential information for boondocking Newbies to have close at hand. Thanks for taking the time to respond. Lorna
Re: Multimeters- Was Elec ? Reply #10 – February 21, 2003, 09:56:11 am Yahoo Message Number: 19201Lorna and anyone else who may need this info, Here is a link to a site that has the figures Gus just posted plus a temperature compensation chart. This is important to get a more accurate reading of your state of charge. For those of us who live in cloder climates, our readings will tend to be lower than normal. http://uuhome.de/william.darden/dcfaq3.htmThis site is also good for general battery info.-Victor
Re: Multimeters- Was Elec ? Reply #11 – February 21, 2003, 10:27:25 am Yahoo Message Number: 19205QuoteSteve, it's a "Pocket Size 18-Range Digital Multimeter." Says it's a 3-3/4 digit display that can show up to 3,200 units; measures AC and DC voltage up to 500 V each and resistance up to 30 M .. which translated, means?!! Lorna 3 3/4 digits means the display will read up to 3199. For instance, if measuring a varying voltage that is incresing towards 5 Volts, the display will indicate four digits of resolution until it reaches 3.199 Volts, then will read three digits of resoltution from 3.20 Volts up to 5.00 Volts. If measuring up to 100V, the reading will jump from 31.99 Volts to 32.0 Volts, etc. The 500V limit is the highest voltage which won't destroy the meter, and 30 Megohms (30 million Ohms) is the highest resistance - a measure of a circuit's resistance to current flow - the meter will register. Ohms are a unit of resistance (R) and are related to the voltage across a circuit (V) and the current through that circuit ('A', amps, or Amperes) by Ohm's Law: V = A X R.For the Ohms scales, the more important specification for most 12V systems is how LOW a resistance the meter will resolve. Also, does the meter read current? A separate 10 Amp range can be very useful. There should be a model number (or Radio Shack stock #) on the meter or in it's literature. If I have that, I can check on it and give you a lot more specific info for that model.Steve
Re: Multimeters- Was Elec ? Reply #12 – February 24, 2003, 02:57:37 pm Yahoo Message Number: 19266QuoteThere should be a model number (or Radio Shack stock #) on the meter or in it's literature. If I have that, I can check on it and give you a lot more specific info for that model.Steve Victor and Steve, thanks for the additional information. Knowing my limitations, however, I think I'm fast approaching the TMI point. Steve, No reference number on the gadget or the booklet to identify the model. And Victor, the website is definitely a useful resource, but I'm thinking what I really need is an "Electronics for Dummies" book! Or, better yet, if I have a problem down the road I may just have to look you guys up! Lorna (still waiting in Sunny Washington)
Re: Multimeters- Was Elec ? Reply #13 – February 24, 2003, 03:34:36 pm Yahoo Message Number: 19269lornadunham wrote:Quote aq433 wrote: There should be a model number (or Radio Shack stock #) on the meter or in it's literature. If I have that, I can check on it and give you a lot more specific info for that model.SteveVictor and Steve, thanks for the additional information. Knowing my limitations, however, I think I'm fast approaching the TMI point. Steve, No reference number on the gadget or the booklet to identify the model. And Victor, the website is definitely a useful Lorna, it may be model 22-802? Search by that number on www.radioshack.com or if this link works:http://www.radioshack.com/product.asp?catalog%5Fname=CTLG&category% 5Fname=CTLG%5F008%5F002%5F001%5F000&product%5Fid=22%2D802This model has no current ranges, and is thus less useful generally than some other models. However, the voltage range gives good resolution, and you will be unlikely to get into trouble using this meter than those others, and that should give you more confidence to use it. You should need only to switch to the VDC scale - the one next to 'off', for measuring to find problems in the 12V system of your motorhome.For measuring battery voltage, put the red lead to the '+' terminal of the battery and the black lead to the '-'. It doesn't matter if you get it backwards, the meter will just read the correct voltage with a '-' in front.Steve
Re: Multimeters- Was Elec ? Reply #14 – February 24, 2003, 05:39:38 pm Yahoo Message Number: 19276aq433 wrote:Quote Lorna, it may be model 22-802? Search by that number on www.radioshack.com or if this link works:http://www.radioshack.com/product.asp?catalog%5Fname=CTLG&category% 5Fname=CTLG%5F008%5F002%5F001%5F000&product%5Fid=22%2D802 Lo Steve! On the back of the inst'n booklet, there were some random unidentified numbers: 22-809. And some ccorinating numbers on the back of the meter: "Cat. No.22-809." Am assuming that's the model no. Right? Lorna
Re: Multimeters- Was Elec ? Reply #15 – February 25, 2003, 09:08:41 am Yahoo Message Number: 19285QuoteLo Steve! On the back of the inst'n booklet, there were some random unidentified numbers: 22-809. And some ccorinating numbers on the back of the meter: "Cat. No.22-809." Am assuming that's the model no.Quote Right? Lorna Lorna, that is the model #. A search at Radio Shack produces no picture, but lots of documents. Superficially, at least, it would seem similar to 22-802, based on the owner's manual. That seemed to be unusually well written for an inexpensive imported item, so it is worth reading through. Simply ignore things that don't apply to what you want to do, and I wouldn't worry about removing the meter's batteries each time. You might still check out meter 22-802 on their site, to see if it looks the same as yours.Steve
Electrical question Reply #16 – February 20, 2003, 09:37:35 pm Yahoo Message Number: 19192Hi Laurie What Camping World? What city, what state? Wish I could help with the problem, but I am sure someone will.Mac No Cal
Re: [Life With A Lazy Daze RV] Camping World - was Electrical quest Reply #17 – February 21, 2003, 02:45:13 am Yahoo Message Number: 19199QuoteHi LaurieWhat Camping World? What city, what state? Wish I could help with the problem, but I am sure someone will.Mac No Cal I took it to the Tacoma Washington Camping World. They did a good job installing the LP detector, and I guess an okay job with the batteries, although I should have checked around because their price was way high. Also, I had intended to purchase a new starting battery as well, however they couldn't figure out how to get it in (!?) When I first called them about the possibility of the batteries not holding a charge, at first I was told the batteries were fully charged when installed, then the guy said no they weren't. I don't think they knew.My father also had a frustrating experience with them. He has an Airstream motorhome and needed the A/C repaired. When he made his appointment he explained to them exactly what type of motorhome he had. He took the day off work to drive down there, and they took one look at his rig and said "we don't do those". I guess they tore the aluminum roof of an Airstream once.Anyway, they are probably okay for some things, but I probably will look elsewhere first.Laurie
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