dickandlois Report post Posted November 12, 2018 Bill, I just finished looking back through the entire thread. I have to agree with you. Battery Isolator's can do strange things. There are Diodes in them that can brake down when they get hot. Thing is it is unusual for them to work when they cool down, But I have had it happen on 2 alternators. To reduce the problem _-I in stalled some duct work to inject outside air directly into the area around them. This has extended the alternator life. Good luck bburns and thanks for filling us in regarding you travels South away from the storm. Rich. Share this post Link to post Share on other sites
richard5933 Report post Posted November 12, 2018 A lot of guys in the bus conversion side of things have gone away from battery isolators and just run continuous-duty-rated solenoids to bridge the batteries for charging while on the road. Some even incorporate relays to have the solenoid work automatically. Too many problems possible with the isolators, and they tend to have a voltage drop across them. I went another way and use a Sterling battery-to-battery charger to charge the house batteries from the main engine alternator while underway. It can send up to 70 amps to the 12v house battery bank. Share this post Link to post Share on other sites
kaypsmith Report post Posted November 12, 2018 Actually, I have been in contact with the family just today. The Isolater on this coach is not a diode based one. It is a pretty unique control board that utilizes the same solenoid that engages to combine battery sets, chassis and house when you push the button for start assist. The alternator is just not charging the chassis batteries while the motor is running, the new inverter/converter is charging both sets while on shore power just fine. The alternator seems to only be charging to a 12.3 while the motor is running, the warning light comes on, on the dash while traveling. Yes Richard, I actually engage a solenoid to charge the house batteries on my coach while driving, I prefer the k.i.s.s. method also, I'm fortunate that my MCI is equipped with a battery equalizer which makes pulling from one battery on the 24 volt system not stressful on the other battery. I know many older conversions that actually run a 12 volt alternator also just for the purpose of charging the house batteries while traveling. Share this post Link to post Share on other sites
richard5933 Report post Posted November 12, 2018 9 hours ago, kaypsmith said: The alternator seems to only be charging to a 12.3 while the motor is running, the warning light comes on, on the dash while traveling. Does the vehicle have a separate voltage regulator? If so, it sounds like that might be the culprit. Share this post Link to post Share on other sites
kaypsmith Report post Posted November 12, 2018 33 minutes ago, richard5933 said: Does the vehicle have a separate voltage regulator? Could possibly, I wasn't able to find one when I was checking the coach out, but that was my first recommendation to change before changing the alternator if there was one. Share this post Link to post Share on other sites
f433921 Report post Posted November 12, 2018 Has the belt been checked to see if it is tight? Jim Share this post Link to post Share on other sites
bburns8 Report post Posted November 14, 2018 On 11/12/2018 at 10:37 AM, F433921 said: Has the belt been checked to see if it is tight? Jim No, they haven't got to us yet. Share this post Link to post Share on other sites
bburns8 Report post Posted November 14, 2018 Do the following volt readings on the HOUSE batteries indicate an issue? We have a new inverter/charger. House Batteries Plugged into shore power = 14.40 volts Unplugged from shore power = 12.60 volts Unplugged from shore power and Generator turned ON = 14.51 volts Share this post Link to post Share on other sites
wolfe10 Report post Posted November 14, 2018 Close to normal, though 12.6 is just a little low for fully charged battery at rest. The issue will be how quickly the batteries drop from 12.6 to 12.2 with shore power and generator off. Could also load test them-- free at most places that sell batteries. Batteries will need to be fully charged to have reliable results from the load test. Share this post Link to post Share on other sites
bburns8 Report post Posted November 17, 2018 Alternator update: They replaced a wire that goes to the alternator. We checked the chassis batteries with our voltmeter with the coach at idle with nothing on (generator off), but the headlights turned on. The chassis battery reading was 13.01 volts. Next, we drove the MH on the freeway 20 miles with nothing on (generator off), but headlights turned on. We rechecked the chassis batteries and the reading was 13.42 volts. The volt gauge on the driver's dash stayed just to the right side of the center line. Is this an indication that something is still not working correctly to charge the chassis batteries? My understanding is the chassis batteries should read between 13.86 - 14.2 volts. Share this post Link to post Share on other sites
kaypsmith Report post Posted November 17, 2018 53 minutes ago, bburns8 said: Is this an indication that something is still not working correctly to charge the chassis batteries? Probably not a bad indication. As long as they are staying north of 13 volts should be a good sign, depending on the amount of charge that the batteries already have. The fact that the batteries actually went upward to 13.42 is a good sign. When the engine is not running and nothing else on, 12.8 is to be expected. A good test now is to run as much 12 volt accessories as possible, take that 20 mile drive again then check the batteries, if over 13 at this time and engine is at idle, you should be good to go. Hope you have better sailing from now on. Kay Share this post Link to post Share on other sites
richard5933 Report post Posted November 17, 2018 Did you check it while driving on the freeway or after you got off the freeway? If this was the voltage after, then it sounds ok. Probably was higher while actually driving. If you have a way to keep the meter connected while driving you should be able to see the voltage go up a bit when the engine is operating at freeway speeds. Share this post Link to post Share on other sites
bburns8 Report post Posted November 17, 2018 On 11/14/2018 at 5:05 PM, wolfe10 said: The issue will be how quickly the batteries drop from 12.6 to 12.2 with shore power and generator off. Ok, here is volt readings for the house batteries. Plugged into shore power = 14.19 volts Unplugged from shore power checked voltage immediately =12.85 volts Waited 30 minutes still unplugged from shore power and checked voltage again = 12.44 volts Unplugged from shore power and Generator turned on/running for 5 min = 14.42 volts Generator running for 30 min then turned the generator off and checked voltage immediately = 13.55 volts Waited 30 min with generator still turned off (not plugged into shore power) = 12.73 volts What do you think? Share this post Link to post Share on other sites
bburns8 Report post Posted November 17, 2018 14 hours ago, kaypsmith said: Probably not a bad indication. As long as they are staying north of 13 volts should be a good sign, depending on the amount of charge that the batteries already have. The fact that the batteries actually went upward to 13.42 is a good sign. When the engine is not running and nothing else on, 12.8 is to be expected. A good test now is to run as much 12 volt accessories as possible, take that 20 mile drive again then check the batteries, if over 13 at this time and engine is at idle, you should be good to go. Hope you have better sailing from now on. Kay Ok. Does the 12 volt accessories affect the chassis batteries? I thought the 12 volt accessories only affected the house batteries. Share this post Link to post Share on other sites
bburns8 Report post Posted November 17, 2018 14 hours ago, richard5933 said: Did you check it while driving on the freeway or after you got off the freeway? If this was the voltage after, then it sounds ok. Probably was higher while actually driving. If you have a way to keep the meter connected while driving you should be able to see the voltage go up a bit when the engine is operating at freeway speeds. Checked after driving with the engine idling. Share this post Link to post Share on other sites
richard5933 Report post Posted November 17, 2018 On 11/17/2018 at 11:55 AM, bburns8 said: Checked after driving with the engine idling. Then I'd say you're good to go. Your batteries charging. On 11/17/2018 at 11:51 AM, bburns8 said: Ok. Does the 12 volt accessories affect the chassis batteries? I thought the 12 volt accessories only affected the house batteries. Chassis accessories affect the chassis batteries, house accessories affect the house battere. There are both. Things like the dash a/c fan, dash stereo, etc probably run from the chassis batteries, as would anything that only runs with the key turned on. Share this post Link to post Share on other sites
kaypsmith Report post Posted November 18, 2018 Yes chassis accessories include headlights, tail lights clearance lamps dash AC including the dash fan which also blows with the heat from the motor, usually also includes leveling jacks, not all coaches are wired this way for leveling jacks, but most are. All of your house appliances including lighting, camper style refrigeration, furnace blower, heat controls for hot water, water pump for fixtures, and thermostats for heat and air are used from the house batteries. Hope this helps. The readings quoted in the last replies are all favorable, just remember when checking with the motor running, or with the inverter/converter plugged into shore power, or generator, I would be expecting 13+ volts and without motor or inverter/converter then 12.8 is good readings because there is no charging going on in this condition, and the house batteries will slowly discharge due to fixtures inside the coach pulling against them. In your setup, house fixtures should only pull against house batteries, not the chassis batteries because there is solenoid type isolator that is automatically activated when the coach motor is running, this disengages when the motor stops. The combiner switch on the dash activates this same solenoid when pushed manually to give chassis batteries a boost in the event they are too weak to crank the coach, it should only be used in an emergency situation. Share this post Link to post Share on other sites
bburns8 Report post Posted November 18, 2018 On 11/17/2018 at 2:40 PM, richard5933 said: Then if day you're good to go. Your batteries charging. Chassis accessories affect the chassis batteries, house accessories affect the house battere. There are both. Things like the dash a/c fan, dash stereo, etc probably run from the chassis batteries, as would anything that only runs with the key turned on. Thank you 17 hours ago, kaypsmith said: Yes chassis accessories include headlights, tail lights clearance lamps dash AC including the dash fan which also blows with the heat from the motor, usually also includes leveling jacks, not all coaches are wired this way for leveling jacks, but most are. All of your house appliances including lighting, camper style refrigeration, furnace blower, heat controls for hot water, water pump for fixtures, and thermostats for heat and air are used from the house batteries. Hope this helps. The readings quoted in the last replies are all favorable, just remember when checking with the motor running, or with the inverter/converter plugged into shore power, or generator, I would be expecting 13+ volts and without motor or inverter/converter then 12.8 is good readings because there is no charging going on in this condition, and the house batteries will slowly discharge due to fixtures inside the coach pulling against them. In your setup, house fixtures should only pull against house batteries, not the chassis batteries because there is solenoid type isolator that is automatically activated when the coach motor is running, this disengages when the motor stops. The combiner switch on the dash activates this same solenoid when pushed manually to give chassis batteries a boost in the event they are too weak to crank the coach, it should only be used in an emergency situation. Thank you Kay. This is very helpful! Share this post Link to post Share on other sites
bburns8 Report post Posted November 18, 2018 I'm concerned about the HOUSE batteries when plugged into shore power. Shore power should be keeping the house batteries charged/topped off. I know 14.19 volts is a float charge and when unplugged from shore power the volts immediately drop to 12.85 volts which shows the batteries have a charge but, what concerns me is the volts on the house batteries drops again 30 minutes later to 12.44 volts which is not good. Is this normal? Share this post Link to post Share on other sites
wolfe10 Report post Posted November 18, 2018 First, 14.19 is fine for BULK MODE, but high for float unless ambient temperature is around freezing. And, yes 12.44 is low, even if disconnected from shore power unless you are running a lot of 12 VDC things in the coach. If that 12.44 was still while plugged in, indeed you have a problem with the batteries or charger. Share this post Link to post Share on other sites
bburns8 Report post Posted November 18, 2018 50 minutes ago, wolfe10 said: First, 14.19 is fine for BULK MODE, but high for float unless ambient temperature is around freezing. And, yes 12.44 is low, even if disconnected from shore power unless you are running a lot of 12 VDC things in the coach. If that 12.44 was still while plugged in, indeed you have a problem with the batteries or charger. The volt reading plugged into shore power is always in the 14.19 volt range. Once I unplug from shore power it drops to 12.44 after 30 min. Is this a battery issue? Share this post Link to post Share on other sites
wolfe10 Report post Posted November 18, 2018 Yes, very likely bad batteries. Fully charge them and have them load tested. Most any place that sells batteries will do this for free. Share this post Link to post Share on other sites
bburns8 Report post Posted November 18, 2018 20 minutes ago, wolfe10 said: Yes, very likely bad batteries. Fully charge them and have them load tested. Most any place that sells batteries will do this for free. Thank you Wolfe10 Share this post Link to post Share on other sites
richard5933 Report post Posted November 18, 2018 Could a bad battery also be keeping the charger at the 14.19v level? Perhaps it's seeing the bad battery the same as a discharged battery and is pushing through the higher voltage in an attempt to get it charged. I'm curious if the voltage level will correct itself once a known set of good batteries are connected and charged. If not, I'd be concerned that the charger would overcharge if it stayed at 14.19v at all times. Share this post Link to post Share on other sites
manholt Report post Posted November 20, 2018 BB, all it takes is one bad cell. Load test them...mine go to 14.4 bulk, 13.6 float. I replaced all 10 of mine, with AGM's...best thing I ever did. Share this post Link to post Share on other sites