We woke up this AM to weak batteries for 12 volt. We have been on the road for a week with no problem until now. Starting the engine will recharge them. Any ideas on trouble shooting this problem on a 2008, Built for Two? Will appreciate any ideas.
Joe and Nancy
RV 12 volt batteries not recharging
Moderator: bfadmin
Joe & Nancy,
Please give us some more info to possibly help you with your coach batteries problem. What loads were on your batteries the night before waking up with dead batteries.
Depending on the condition of your batteries, the furnace fan when running draws about 6 amps and will generally discharge a pair of coach batteries in two evening. This might be your normal discharge problem if you are overnighting in cold weather conditions and running the furnace.
Also, slide you batteries out and check the water level in each cell. The water/acid level should be above the top of the lead plates and should be up to the level of the two slots at the bottom of the fill hole. If the water/acid level has been way below the top of the lead plates for some time, this will damage the batteries and trigger the need to replace them.
Also running the DC lights and DC powered TV can drain the batteries if left on for long persiods of time.
Lastly, if your coach batteries are 5 years old or more, their capacity to hold a full charge can suffer significantly.
Is your coach equipped with a generator?
Please give us some more info to possibly help you with your coach batteries problem. What loads were on your batteries the night before waking up with dead batteries.
Depending on the condition of your batteries, the furnace fan when running draws about 6 amps and will generally discharge a pair of coach batteries in two evening. This might be your normal discharge problem if you are overnighting in cold weather conditions and running the furnace.
Also, slide you batteries out and check the water level in each cell. The water/acid level should be above the top of the lead plates and should be up to the level of the two slots at the bottom of the fill hole. If the water/acid level has been way below the top of the lead plates for some time, this will damage the batteries and trigger the need to replace them.
Also running the DC lights and DC powered TV can drain the batteries if left on for long persiods of time.
Lastly, if your coach batteries are 5 years old or more, their capacity to hold a full charge can suffer significantly.
Is your coach equipped with a generator?
Bill Hemme - Spencer, Iowa
E-mail: whemme@earthlink.net
2002 Born Free (Ford E-450 V10) 26' RSB
2016 VW Golf GTI - toad
E-mail: whemme@earthlink.net
2002 Born Free (Ford E-450 V10) 26' RSB
2016 VW Golf GTI - toad
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al1florida
All of what Bill said above, plus:
1. If you are looking at your monitor panel to see if your batteries are fully charged at the end of the day of driving you may be looking at a surface charge. If this is the case, check the monitor after a couple of hours of just using the lights, or if the furnace is running quite a bit, check after one hour or so. If the monitor is not showing the batteries as still full, then the batteries are either not capable of holding a charge as well as they used to, or they are not being charged well enough.
2. The engine doesn't do the best job of charging the house batteries. It's main purpose in life is to take care of the engine (chassis) battery. It does do a good job of keeping the house batteries charged if the batteries are not too far discharged and if the engine is running 6 or more hours in a day.
3. If you have not been connected to shore power overnight, 14-16 hours, in the last week, your batteries may be getting farther and farther discharged each day.
4. If the electrolyte (water) in the batteries in any one cell is below the level of the plates this will just amplify the problem.
5. A 2008 BF could have batteries built in 2007 and they are now going on 7 years old. This too will amplify the problem.
1. If you are looking at your monitor panel to see if your batteries are fully charged at the end of the day of driving you may be looking at a surface charge. If this is the case, check the monitor after a couple of hours of just using the lights, or if the furnace is running quite a bit, check after one hour or so. If the monitor is not showing the batteries as still full, then the batteries are either not capable of holding a charge as well as they used to, or they are not being charged well enough.
2. The engine doesn't do the best job of charging the house batteries. It's main purpose in life is to take care of the engine (chassis) battery. It does do a good job of keeping the house batteries charged if the batteries are not too far discharged and if the engine is running 6 or more hours in a day.
3. If you have not been connected to shore power overnight, 14-16 hours, in the last week, your batteries may be getting farther and farther discharged each day.
4. If the electrolyte (water) in the batteries in any one cell is below the level of the plates this will just amplify the problem.
5. A 2008 BF could have batteries built in 2007 and they are now going on 7 years old. This too will amplify the problem.
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tomzleapin
- Posts: 485
- Joined: Sun Jun 20, 2010 9:15 am
Actually the engine does do the best job of charging. Your engine battery will usually be fully charged. This leaves most of the output of the alternator available for charging the coach batteries.al1florida wrote: 2. The engine doesn't do the best job of charging the house batteries. It's main purpose in life is to take care of the engine (chassis) battery. It does do a good job of keeping the house batteries charged if the batteries are not too far discharged and if the engine is running 6 or more hours in a day.
Quote from Born Free manual:
(1) Driving the motorcoach (the vehicle will charge the coach battery from the alternator). This is the best source of charge.
Tom
2005 24' RB
Towing 2016 Mini Cooper convertible on tow dolly
New Hope, MN
2005 24' RB
Towing 2016 Mini Cooper convertible on tow dolly
New Hope, MN
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al1florida
I'm not saying the alternator won't charge the house batteries.
If you just use your house batteries to power the lights at night and lightly use the furnace and then drive for 4-8 hours the next day, the alternator does a great job of recharging the house batteries.
If you run the lights, a TV, a couple of laptops and use the furnace extensively then you may not be fully recharging the batteries each day. If you do drive for 8-9 hours each day then the batteries will get pretty well charged. However if you only drive 4-6 hours then they may not be full recharged.
Do this for a week and your batteries will be pretty far down. (Which may have happened to the original poster. Or they may have weak batteries if the batteries are 7-8 years old.)
My BF is set up with a Trimetric battery monitor to show and track exactly how much power is used from my 2 batteries and how much is flowing back in when being charged.
When my 2 house batteries (total capacity of about 200 amp hours AH) are discharged down to 75% to 50% full (50 AH to 100 AH used) any charging system must put back in current for a fairly long period. If the batteries are down by 100 AH then a current flow of 20 amps must flow back into the batteries for 5 hours to fully charge the batteries.
What happens when charging from the alternator is the initial current flow will be 25-35 amps for 10-15 minutes and then start tapering off to around 15-20 amps after 1 hour and then drops to 7-10 amps after 1.5 to 2 hours. It drops even lower after 3-5 hours. If I only drive for 4-5 hours a day there is no way my batteries get fully charged when used extensively. I can see the AH deficit in my battery monitor. It does show the batteries are not fully charged.
More food for thought: The engine alternators purpose in life is to sense the engine battery and keep it charged. So the first battery it senses is the engine battery about 2 feet or less from the alternator and not the house batteries at the far end of a wire 10-15 feet long. That the alternator does keep the house batteries charged as well as it does is amazing.
If you just use your house batteries to power the lights at night and lightly use the furnace and then drive for 4-8 hours the next day, the alternator does a great job of recharging the house batteries.
If you run the lights, a TV, a couple of laptops and use the furnace extensively then you may not be fully recharging the batteries each day. If you do drive for 8-9 hours each day then the batteries will get pretty well charged. However if you only drive 4-6 hours then they may not be full recharged.
Do this for a week and your batteries will be pretty far down. (Which may have happened to the original poster. Or they may have weak batteries if the batteries are 7-8 years old.)
My BF is set up with a Trimetric battery monitor to show and track exactly how much power is used from my 2 batteries and how much is flowing back in when being charged.
When my 2 house batteries (total capacity of about 200 amp hours AH) are discharged down to 75% to 50% full (50 AH to 100 AH used) any charging system must put back in current for a fairly long period. If the batteries are down by 100 AH then a current flow of 20 amps must flow back into the batteries for 5 hours to fully charge the batteries.
What happens when charging from the alternator is the initial current flow will be 25-35 amps for 10-15 minutes and then start tapering off to around 15-20 amps after 1 hour and then drops to 7-10 amps after 1.5 to 2 hours. It drops even lower after 3-5 hours. If I only drive for 4-5 hours a day there is no way my batteries get fully charged when used extensively. I can see the AH deficit in my battery monitor. It does show the batteries are not fully charged.
More food for thought: The engine alternators purpose in life is to sense the engine battery and keep it charged. So the first battery it senses is the engine battery about 2 feet or less from the alternator and not the house batteries at the far end of a wire 10-15 feet long. That the alternator does keep the house batteries charged as well as it does is amazing.
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tomzleapin
- Posts: 485
- Joined: Sun Jun 20, 2010 9:15 am
Al,
What you are saying is true, but the converter in my 2005 coach does a much worse job of charging my batteries than the alternator. It would take longer to charge my batteries using the converter.
I dry camp virtually 100% and rely on solar to keep my batteries charged. Without solar, I don't think I could run my generator long enough to get a decent charge. I have a 90 amp battery charger that I use for times when there is not enough sunshine.
What you are saying is true, but the converter in my 2005 coach does a much worse job of charging my batteries than the alternator. It would take longer to charge my batteries using the converter.
I dry camp virtually 100% and rely on solar to keep my batteries charged. Without solar, I don't think I could run my generator long enough to get a decent charge. I have a 90 amp battery charger that I use for times when there is not enough sunshine.
Tom
2005 24' RB
Towing 2016 Mini Cooper convertible on tow dolly
New Hope, MN
2005 24' RB
Towing 2016 Mini Cooper convertible on tow dolly
New Hope, MN
Tom,
The charger/converter in your 2005 BF coach is probably the single-stage Parallax 7345 which is really slow at recharging your house batteries either plugged into shore line power or by running your generator. Anyone doing a lot of dry camping should consider changing out the Parallax 7345 charger/converter and replacing it with a modern 3-stage charger/converter such as the Progressive Dynamics PD4655 unit. That unit will charge deeply discharged house batteries up to a 90% charge level within 3 hours.
Refer to my post in the Coach Modifications section of this website titled Converting Parallax 7345 Charger/Converter to PD4655 system. You will be doing your house batteries a great favor in making this conversion.
The charger/converter in your 2005 BF coach is probably the single-stage Parallax 7345 which is really slow at recharging your house batteries either plugged into shore line power or by running your generator. Anyone doing a lot of dry camping should consider changing out the Parallax 7345 charger/converter and replacing it with a modern 3-stage charger/converter such as the Progressive Dynamics PD4655 unit. That unit will charge deeply discharged house batteries up to a 90% charge level within 3 hours.
Refer to my post in the Coach Modifications section of this website titled Converting Parallax 7345 Charger/Converter to PD4655 system. You will be doing your house batteries a great favor in making this conversion.
Bill Hemme - Spencer, Iowa
E-mail: whemme@earthlink.net
2002 Born Free (Ford E-450 V10) 26' RSB
2016 VW Golf GTI - toad
E-mail: whemme@earthlink.net
2002 Born Free (Ford E-450 V10) 26' RSB
2016 VW Golf GTI - toad
-
tomzleapin
- Posts: 485
- Joined: Sun Jun 20, 2010 9:15 am
Bill,
I agree that upgrading to a 3 stage converter is well worth considering for anyone that dry camps. I seldom need to run my generator since my solar does a great job of keeping my batteries charged. The 90 amp charger that I have works well. I bought it on Craigs List for $25 and managed to squeeze in under the refrigerator. If it ever dies, I would definitely upgrade my converter.
I agree that upgrading to a 3 stage converter is well worth considering for anyone that dry camps. I seldom need to run my generator since my solar does a great job of keeping my batteries charged. The 90 amp charger that I have works well. I bought it on Craigs List for $25 and managed to squeeze in under the refrigerator. If it ever dies, I would definitely upgrade my converter.
Tom
2005 24' RB
Towing 2016 Mini Cooper convertible on tow dolly
New Hope, MN
2005 24' RB
Towing 2016 Mini Cooper convertible on tow dolly
New Hope, MN
-
Ray
I think everyone has made some very valid points, and its very hard to dispute a good battery monitoring system.
I think battery's and the discharge and charging of them is the most misunderstood thing we may have on our RV's.
I would like to add just a couple comments. Very important point that the alternator sense's the state of charge and adjusts accordingly. When your couch batteries are down and your chassis battery isn't the alternator will not put out a full charge rate - so the statement that the alternator is the best source of charge may or may not be correct depending on other factors. There are allot of variables to consider - you also have to remember that the alternator is designed for full output at a engine RPM higher than idle.
The comment about the state of charge of all battery's also enforces the importance of insureing that your coach batteries are the same brand, size, age, and state of condition - not only the alternator but also the charging system will monitor the over all state of charge of the bank and adjust accordingly (if you have a good charger) so if one battery's charge or acceptance of charge is different than the other you will not be charging at peak efficiency and you could actually damage the best battery in the bank.
Another whole subject is charging and maintaining batteries properly to extend the life cycle, sometimes by a very large factor - anytime a battery is sitting in a discharged state the battery is damaging itself, and if incorrectly charged the life cycle of the battery will be shortened also. With the RV batteries people generally accept replacing every 4 - 5 years. I think the batteries in my boat inverter battery bank are going on about 10 or 11 years now, their efficiency is down a bit but they still function acceptably (will will see this spring) I monitor those charge and discharge cycles closely as replacement cost for them is around $600 - $700 each.
Bill, Al - I am going to check into the PD4655 converter and the Trimectric monitoring system - I have not done anything with the RV battery/charging system as yet except check the batteries about every time I get close to them
I know it isnt the best setup for the batteries.
Thank You for all the great info
I think battery's and the discharge and charging of them is the most misunderstood thing we may have on our RV's.
I would like to add just a couple comments. Very important point that the alternator sense's the state of charge and adjusts accordingly. When your couch batteries are down and your chassis battery isn't the alternator will not put out a full charge rate - so the statement that the alternator is the best source of charge may or may not be correct depending on other factors. There are allot of variables to consider - you also have to remember that the alternator is designed for full output at a engine RPM higher than idle.
The comment about the state of charge of all battery's also enforces the importance of insureing that your coach batteries are the same brand, size, age, and state of condition - not only the alternator but also the charging system will monitor the over all state of charge of the bank and adjust accordingly (if you have a good charger) so if one battery's charge or acceptance of charge is different than the other you will not be charging at peak efficiency and you could actually damage the best battery in the bank.
Another whole subject is charging and maintaining batteries properly to extend the life cycle, sometimes by a very large factor - anytime a battery is sitting in a discharged state the battery is damaging itself, and if incorrectly charged the life cycle of the battery will be shortened also. With the RV batteries people generally accept replacing every 4 - 5 years. I think the batteries in my boat inverter battery bank are going on about 10 or 11 years now, their efficiency is down a bit but they still function acceptably (will will see this spring) I monitor those charge and discharge cycles closely as replacement cost for them is around $600 - $700 each.
Bill, Al - I am going to check into the PD4655 converter and the Trimectric monitoring system - I have not done anything with the RV battery/charging system as yet except check the batteries about every time I get close to them
I know it isnt the best setup for the batteries.Thank You for all the great info