grandview bill Posted August 20, 2013 Share Posted August 20, 2013 One of the first things I noticed when I removed the battery,to work on the mounting box ,was this battery is wrong.This battery was labled 'marine cranking' which means ant starting service.the correct battery for our rv are the deep cycle type.This battery is meant to be drawn down to a low level of charge repeatedly.The battery in my coach is meant to be used to start engines,short duty and less draw down.I dont want to buy a new battery,actually this one is new i have the receipt.So,whats the problem? its a battery isnt it?The issue becomes one of capacity for my use.How much power will this provide for how long?amp/hrs.I did a simple test....first I made sure the battery was fully charged.The system monitor showed 100%/my DVM showed 13.5 volts and the 'green eye' on the battery was showing.Now to add some load ...I turned on six interior lites...left them on while i monitored the voltage..basically the lites were on for about 6 hours,then the voltage dropped dramatically.So what?I dont care too much about the lites you can see the dimming....but this fall Iwill want to use the furnace,years ago (1979 Campmate)this was a non electric heater,nowa days with the forced air units you need a charged battery to run ...there is a sail switch internally which measures air flow,a safety system, inadequate air flow.....caused by weak battery charge.....no heat...Ican sleep in No.Minn. with it cold at nite....but I like it warm..when I make the first trip to the rear in the morning Quote Link to comment Share on other sites More sharing options...
waiter Posted August 20, 2013 Share Posted August 20, 2013 The Marine starting battery is a compromise between marine and start.. Not as good as a deep cycle, but will work.You might consider one of the vent-less heaters. I use a Mr Buddy that I modified to run off the house propane system. John Mc 88 Dolphin 4 Auto Quote Link to comment Share on other sites More sharing options...
Maineah Posted August 20, 2013 Share Posted August 20, 2013 All ways carry a set of jumper cables that way you can start your lawn mower to charge your battery if you kill the coach battery! I put a computer thermostat in mine that has a timer just comes on about 65 around the time I want to get up or the inside drops below 50. I keep looking at the vented cat heaters but then I come to my senses when I look at the price. Quote Link to comment Share on other sites More sharing options...
grandview bill Posted August 20, 2013 Author Share Posted August 20, 2013 i notice in the Winnebago manual the Toyota is the only chassis where the batteries,coach and cab cant be paralelled...wonder why? Ok for ford and chev Quote Link to comment Share on other sites More sharing options...
zero Posted August 20, 2013 Share Posted August 20, 2013 i notice in the Winnebago manual the Toyota is the only chassis where the batteries,coach and cab cant be paralelled...wonder why? Ok for ford and chev What Ford or Chevy allows a permanent parallel circuit for two disimilar batteries? That makes no sense. A cranking battery and a "house" deep cycle battery will have slightly different nominal voltages and that creates a situation where the batteries try to equalize voltage and discharge. Ford and Chevy's have parallel cranking batteries in diesel trucks because the two batteries are perfectly matched. I've also seen many RVs that have a emergency start function that will parallel the cranking battery with the house battery but that is for a momentary use. Even battery banks with parallel circuits and matched batteries have problems when a new battery of the same part # gets mixed with older batteries. That because nominal voltage tends to drop with age. Quote Link to comment Share on other sites More sharing options...
Maineah Posted August 21, 2013 Share Posted August 21, 2013 Paralleled batteries kind of defeats the entire ideal of isolation. Maybe Ford and Chevy think a dead truck battery in the morning is a good thing. Hint when they are charging with the engine running they are paralleled. I think Winnebago's wording lacks a little. Quote Link to comment Share on other sites More sharing options...
grandview bill Posted August 21, 2013 Author Share Posted August 21, 2013 maybe its my wording ,no the are not in paralell all the time.batt/mom momentary switch' press while turning key for additional starting power not available on Toyota chassis'i said cant be paralelled.if they can be paralelled for emergency engine starting ,that would also work in reverse you said permanent not me Quote Link to comment Share on other sites More sharing options...
mission mike Posted August 21, 2013 Share Posted August 21, 2013 http://www.marxrv.com/12volt/12volt.htm not sure if this as been posted before, it has some useful information. Quote Link to comment Share on other sites More sharing options...
zero Posted August 21, 2013 Share Posted August 21, 2013 maybe its my wording ,no the are not in paralell all the time.batt/mom momentary switch' press while turning key for additional starting power not available on Toyota chassis'i said cant be paralelled.if they can be paralelled for emergency engine starting ,that would also work in reverse you said permanent not me I've got two RVs here with a temp parallel switch for emergency starting (Ford and a Winnebago Phasar). To have a setup that's effective - large diameter electric cable is needed between the two batteries. I suppose many RV makes chose NOT to do it since there are as many "downsides" to it as "upsides." A dead battery can quickly drain the good batttery when paralleled. Yes, I'm the one that mentioned "permanent." i did so to be clear. All Toyotas come wired with "temporary" parallel hookup so why wouldn't I clarify? Every time you start a Toyota RV - and it's wired correctly - both batteries get hooked in parallel to be charged. As long as the engine is running and charging - they STAY in parallel. What you are referriing to - although you failed to clarify - is parallel for starting purposes only. When using parallel charging - a cable only needs to be big enough to prevent voltage drop that meets the max charge rate. To do the same for starting purposes - it needs to carry more amps and be larger. A starter motor needs 200-300 amps for good cranking. A Toyota charging system only 45-60 amps. Besides - not a great setup as I see it. if you have one stone dead battery - and one full charged - and parallel them together - the dead battery immediately starts sucking power from the one and will quickly kill it. If I was stuck with a dead battery in front - I'd rather disconnect the dead battery and then hook in the good "house" battery. Quote Link to comment Share on other sites More sharing options...
Maineah Posted August 21, 2013 Share Posted August 21, 2013 Many rv set ups have a spring loaded switch to turn on the isolator relay to combine both batteries for a short charge of a weak truck battery most of the systems are fed with #8 wire and 30 amp breakers so it would take awhile to kill the good battery but it's often is just enough kick to bring a weak battery up enough to effect a start Quote Link to comment Share on other sites More sharing options...
zero Posted August 21, 2013 Share Posted August 21, 2013 Many rv set ups have a spring loaded switch to turn on the isolator relay to combine both batteries for a short charge of a weak truck battery most of the systems are fed with #8 wire and 30 amp breakers so it would take awhile to kill the good battery but it's often is just enough kick to bring a weak battery up enough to effect a start My 86 Winnebago Phasar has a push button on the dashboard to do just that. I never explored it to see how it works. I suppose it has a HD relay. A #8 wire hooked to a 30 amp breaker connecting a near dead battery to a full charged battery is going to result in a huge rush of current and a tripped breaker if only 30 amps. I don't see how that's going to be very effective unless the cranking battery is only slightly run down. I've got #2 cable and a 100 amp slow-blow fuse on my 78 Toyota to connect both batteries but that's there to carry charge current from the front to the back and not vice-versa. Quote Link to comment Share on other sites More sharing options...
grandview bill Posted August 22, 2013 Author Share Posted August 22, 2013 well your wrong..you assume a lot the battery was just bought by the other owner and given to us...why are you making this a male female issue? im not Quote Link to comment Share on other sites More sharing options...
DanAatTheCape Posted August 23, 2013 Share Posted August 23, 2013 wally's world has 2 trolling batteries that fit - maxx29 & one a size smaller. IF you mount it with the positive terminal at the compartment door 2 standard jumper cables hooked end to end will reach from that terminal to the battery under the hood (cheap & easy parallel) Quote Link to comment Share on other sites More sharing options...
Boots Posted May 4, 2014 Share Posted May 4, 2014 This is just plainly a very very very bad idea. Just this last winter, here where I live, two fellows had bought a sail boat, and they did not want to pay for utilities, so they brought a ventless kerosene heater. Two days later they found both of these men dead from carbon monoxide poisoning...yep they saved a lot of money and left behind two families to mourn their passing. Throw your ventless heaters out. Boots Quote Link to comment Share on other sites More sharing options...
5Toyota Posted May 15, 2014 Share Posted May 15, 2014 I just carry a set of jumper cables in case I had to jump off the rv battery. also carry a small old battery charger can plug in to my cheap china whina generater. Quote Link to comment Share on other sites More sharing options...
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