 |
|
11-03-2024, 08:57 AM
|
#15
|
Senior Member
Join Date: Mar 2024
Location: Bohemia NY
Posts: 1,922
|
Quote:
Originally Posted by twinboat
The only thing you'll want to watch is over taxing your alternator while getting on the road if the battery bank is low. A Li-BIM or a DC to CC charger will limit the load on the alternator. Li-Bim is bi-directional so it keeps your chassis battery in shape when on shore or generator power. A DC to DC charger doesn't offer that but it charges to a higher voltage, getting your batteries to 100% SOC.
|
As part of this, as You are becoming more dependent on 12 volt power for the fridge it makes sense to install some type of battery monitoring. A shunt-based system monitoring current in, out, calculating state of charge, and time remaining. There are many out here. Alternator overloading can easily be checked by monitoring the voltage. Using the generator and on-board charger/inverter charger can also be used to bring the state of charge up and supplement the alternator when needed.
__________________
Dennis
Bohemia NY
2008 Nimbus 342 SE Carlyle
|
|
|
 |
Join the #1 RV Forum Today - It's Totally Free!
iRV2.com RV Community - Are you about to start a new improvement on your RV or need some help with some maintenance? Do you need advice on what products to buy? Or maybe you can give others some advice? No matter where you fit in you'll find that iRV2 is a great community to join. Best of all it's totally FREE!
You are currently viewing our boards as a guest so you have limited access to our community. Please take the time to register and you will gain a lot of great new features including; the ability to participate in discussions, network with other RV owners, see fewer ads, upload photographs, create an RV blog, send private messages and so much, much more!
|
11-03-2024, 09:25 AM
|
#16
|
Senior Member
Join Date: Nov 2018
Location: Beaver Dam, Wisconsin
Posts: 5,887
|
get some feedback regarding transitioning from lead acid batteries to possibly lithium. Small capacity, 100 amp hour, lithium batteries are readily available and are now at the same price point or possibly less than some lead acid solutions.
install four 100 amp hour lithium batteries in parallel using a bus setup in order to try to get some semblance of balanced charging and discharging over the four batteries.
I currently have a Freedom 15 inverter charger which I believe has a 70 amp peak charging rate. I believe that at that rate I should not have any problem charging the four small capacity lithium batteries.
That will give me about 320 amp hours to use safely while stopping at an 80% discharge. Considerably more than me I have available now without going below a 50% discharge rate.
70 amp charging will replace 320 amps in about 5 hours. 320ah / 70a = 4.5 h plus some for balancing. Good to go. This assumes the charger has a lithium charging profile. Check owner's manual.
Although I dry Camp often normally it would be for one night at a time while en route to a more permanent destination. My long periods of boondocking are generally for a week at a time at various race tracks. Normally, since I live in the southeast it's almost always necessary for me to run the air conditioner at least a couple of hours each day anyway and of course I generally have to top up the batteries once a day anyway just to be safe.
all I'm really looking for is enough battery capacity to run the fridge for 24 to 48 hours on existing battery power without problems. The unit at the top of my list is a JC refrigeration 2417 which will pretty much fit into the 1201 no cold slot with some minor modifications such as lowering the platform a bit. That unit pulls 4.2 amps when running, and the compressor is surely not going to run every minute of every hour.
Good to go here as well. Running only the JC, 320 amp hours should last 80 hours more or less. 320ah / 4.2a = 80. You will need a substantial shot to start the generator and you will be using some battery capacity for other 12 volt uses, but still you will have plenty.
Life does not always follow mathematical precision, but you appear to have substantial reserve.
You will of course need to protect the RV engine alternator from overloading one way or another. Four 100 amp hour lithium batteries may try to draw 200 amps for charging. They may have the ability to draw 400 amps. See battery manufactures specs.
__________________
Paul Bristol
Kodiak Cub 176RD
Nissan Pathfinder 2015
|
|
|
11-03-2024, 11:03 AM
|
#17
|
Senior Member
Join Date: Jun 2017
Posts: 199
|
Quote:
Originally Posted by d23haynes57
Unless upgraded you have a 160 Amp Leece Neville. I believe your charge control is a simple relay set up. If you go with the 400-460 A/H battery set I recommended they will try to pull ~80 to 100 amps. Plus, the other loads such as that 12-volt fridge. You can bolt on a larger alternator.
|
Going down the road really all I would have going on is recharging the batteries and running the fridge. The only other thing that would be there would be the radio and other minor 12-volt draws like keeping two phones charged. If I had both headlights on on Bright, all the running lights and the fog lamps that would be an additional load but not a whole lot and I don't drive at night anyway. The only time I would have lights on is if I was driving in the rain. I'm thinking that 160 amps of output from the alternator would be more than sufficient. Am I wrong?
|
|
|
11-03-2024, 11:05 AM
|
#18
|
Senior Member
Join Date: Jun 2017
Posts: 199
|
Quote:
Originally Posted by d23haynes57
As part of this, as You are becoming more dependent on 12 volt power for the fridge it makes sense to install some type of battery monitoring. A shunt-based system monitoring current in, out, calculating state of charge, and time remaining. There are many out here. Alternator overloading can easily be checked by monitoring the voltage. Using the generator and on-board charger/inverter charger can also be used to bring the state of charge up and supplement the alternator when needed.
|
I agree, and a lot of the batteries I look at have bluetooth capability in order to use an app to monitor the condition. And yes I think the easiest thing to do if my batteries happen to be low would be to start the Gen set prior to starting the engine and engaging the alternator charge
|
|
|
11-03-2024, 11:09 AM
|
#19
|
Senior Member
Join Date: Jun 2017
Posts: 199
|
70 amp charging will replace 320 amps in about 5 hours. 320ah / 70a = 4.5 h plus some for balancing. Good to go. This assumes the charger has a lithium charging profile. Check owner's manual.
Charger Is original 2002 model designed for FLA batts. Explain to me why I would need a lithium charging profile please.
|
|
|
11-03-2024, 11:28 AM
|
#20
|
Senior Member
Join Date: Mar 2024
Location: Bohemia NY
Posts: 1,922
|
Quote:
Originally Posted by medarwin
I agree, and a lot of the batteries I look at have bluetooth capability in order to use an app to monitor the condition. And yes I think the easiest thing to do if my batteries happen to be low would be to start the Gen set prior to starting the engine and engaging the alternator charge
|
The bluetooth apps become a bit of a problem with multiple batteries. Consider if the batters are in an outside compartment and if you need low temp protection. Or worse if you really need to use them in winter you may need the heated ones, or move the batteries inside. If you stay in the 400 A/H range as you had with the GC-2 you will be fine. You could also do a single 300 A/H but they may limit inverter and generator starting support.
For your set up I have used these as drop ins.
https://www.litime.com/products/12v-...ifepo4-battery
They will fit in the space you have, low temp cut off protection. 2 will give you 460 A/H much more effectively than the lead acid. 2 of these will work. BTDT! Set your inverter/charger to AGM and this BMS will do the rest.
__________________
Dennis
Bohemia NY
2008 Nimbus 342 SE Carlyle
|
|
|
11-03-2024, 12:01 PM
|
#21
|
Senior Member
Join Date: Apr 2021
Location: Annapolis
Posts: 698
|
Tons of good advice above.
When I converted to Lithium, I added a DC-DC charger to protect the alternator (even though its 280 amp), and installed a power shunt since Li voltage is not a good indicator of SOC. The shunt I used also monitors the chassis battery and outside temperature. A single 100Ah LiFePo4 has no problem starting my Onan 3600LP.
The DC-DC charger had a solar input, so I installed a pigtail cable and use a portable 100W panel with a 30 foot cable when parked. The 30 feet allows me to park in the shade and still have a little solar.
The back of my fridge had several areas where the insulation and sealing tape had failed. Before i re-installed it, I fixed the insulation and added a layer of Refletix to the wall behind the fridge. When exposed to the sun that wall would heat up considerably.
My batteries are exposed to the weather, if I had it to do it over I would have installed batteries with low temp charging protection. My DC-DC charger has low temp charging protection, but the converter/charger does not. In cold weather, with AC hook-ups, I manage the charging by flipping the breaker on the converter if its too cold.
__________________
2018 Thor Freedom Elite 24
on 2016 Sprinter Chassis
|
|
|
11-03-2024, 04:40 PM
|
#22
|
Junior Member
Join Date: Jan 2024
Posts: 18
|
I have a 12 fridge in my Jayco. I put in two 200 amp lithium batteries. There is 380 watts of solar on the roof. My converter has a LA and a LI setting on it go to LI and charge voltage is 16.4 volts. My control panel lets me set the solar charge controller to LI and I can adjust the charge voltage set the solar to 14.4 volts. I ran the fridge from about 1 May until 10 Sept. It was only plugged into shore about 10 days. Never had the battery's drop below 50% all summer. Hope this gives you some idea of what to expect.
|
|
|
11-03-2024, 06:49 PM
|
#23
|
Senior Member
Join Date: Aug 2017
Posts: 447
|
MEDARWIN,
I installed a 12 volt Dometic 4101? a couple of years ago and its been great even with my old propane/electric working fine with great temps. I ran the 12 volt wiring straight to a buss bar that attached to the 4- 6 volt batteries. With these batteries I can easily go 24+ hours using the TV and a few lights at night.
I also have the Freedom 15 inverter charger and believe it will charge a cool gel battery at 14.4 volts by adjusting the dip switches. This should be enough for for most modern lithium batteries, but check before buying batteries.
I am also looking to add lithium to my rig, but with solar. I have already bought 600 watts of solar panels and a victron charge controller. I will soon buy a 460 AH lithium battery and a DC to DC charger or a Li? controller for the alternator. I also considered 4 100 ah, but decided to go a little bigger for a little more $.
This should allow me to run the refrigerator on solar and the battery without the generator. I also live in the SE so I usually have the generator running anytime I am driving in warmer weather.
I plan to do this now because my 6 volt batteries are older, but still good so I can still use them on another solar system at my dock for extra amp hours. That and I am tired of checking the water levels in multiple locations.
__________________
Carl
1998 Beaver Patriot Savannah
330 hp Cat 3126 DP
|
|
|
11-04-2024, 07:28 AM
|
#24
|
Senior Member
Join Date: Nov 2018
Location: Beaver Dam, Wisconsin
Posts: 5,887
|
Quote:
Originally Posted by medarwin
70 amp charging will replace 320 amps in about 5 hours. 320ah / 70a = 4.5 h plus some for balancing. Good to go. This assumes the charger has a lithium charging profile. Check owner's manual.
Charger Is original 2002 model designed for FLA batts. Explain to me why I would need a lithium charging profile please.
|
The static voltage of working lead acid batteries is 12.7 to 10.5. The static voltage of working lithium batteries is 13.5 to 12.6. So a lithium battery is fully discharged at the same voltage as a fully charged lead acid battery. This often prevents the lithium batteries from triggering fast charge (14.4 volts) in older chargers.
Lead acid batteries can use 14.4 volts early in the charging cycle. Voltage must drop to 13.6 volts later in the cycle. They can be charged at 13.6 volts just fine even if 14.4 volts is not present.
Most lithium batteries must have 14.4 volts at the end of their cycle to finish the charge and internally balance individual cells. Chargers for lead acid do not provide 14.4 volts at the end of their cycle.
Some lead acid chargers that can be programmed by a user can be changed to produce 14.4 volts all the time or long enough. Most can not.
Some lead acid chargers do not charge until voltage drops below 12.4 volts. By that time a lithium battery has been disconnected inside by the lithium battery monitoring system.
__________________
Paul Bristol
Kodiak Cub 176RD
Nissan Pathfinder 2015
|
|
|
11-04-2024, 09:13 AM
|
#25
|
Senior Member
Join Date: Sep 2020
Location: Shrewsbury
Posts: 447
|
Quote:
Originally Posted by Persistent
The static voltage of working lead acid batteries is 12.7 to 10.5. The static voltage of working lithium batteries is 13.5 to 12.6. So a lithium battery is fully discharged at the same voltage as a fully charged lead acid battery. This often prevents the lithium batteries from triggering fast charge (14.4 volts) in older chargers.
Lead acid batteries can use 14.4 volts early in the charging cycle. Voltage must drop to 13.6 volts later in the cycle. They can be charged at 13.6 volts just fine even if 14.4 volts is not present.
Most lithium batteries must have 14.4 volts at the end of their cycle to finish the charge and internally balance individual cells. Chargers for lead acid do not provide 14.4 volts at the end of their cycle.
Some lead acid chargers that can be programmed by a user can be changed to produce 14.4 volts all the time or long enough. Most can not.
Some lead acid chargers do not charge until voltage drops below 12.4 volts. By that time a lithium battery has been disconnected inside by the lithium battery monitoring system.
|
This is a really good description of the issue with using FLA chargers on LIFEPO batteries. What converter do you have now? Many of the older Progressive Dynamics converters had their "Charge Wizard" built in. This is a 3 stage charger but (as described above) the voltage setpoints don't work well for Lithium. But some have a provision to add a remote pendant that lets you choose the voltage output manually. I've been doing that for the past 4 years. Not as convenient as a new lithium capable converter, but less than $20: https://www.amazon.com/gp/product/B007HS0PAI/
__________________
retired USCG aviator
2020 Jayco Greyhawk 29MV/2021 MINI Cooper toad
|
|
|
11-04-2024, 09:31 AM
|
#26
|
Senior Member
Join Date: Apr 2024
Location: WI Driftlesser
Posts: 2,527
|
https://xantrex.com/wp-content/uploa...ers-Manual.pdf
Here's the manual for the freedom 15, hopefully the right one. The charger uses three stages, bulk, acceptance, and float. Bulk starts as soon as the charger is "activated" but doesn't clarify "activated" in voltage terms if already on. If you turn off and on, it will activate.
Bulk continues at full amp rating, 70A, until 14.5V is reached, then amperage is supplied at whatever the battery will "accept" at 14.5V
"Maximum acceptance time is one hour for
wet and AGM cells and three hours for gel
cells. " OR, until the amperage drops to 12A, then the charger will drop to "float" stage, where it maintains 13.4v. I believe until the amperage exceeds 70A, or possibly with Li the voltage is below 13.4v when it's turned on.
So, my impression of the freedom 15 for charging Li, it will start charging when turned on with battery voltage less than 13.4, it will charge 70a until voltage reaches 14.5, and on the gel setting continue at 14.5v for three hours, or the amps drop to 12, whichever is first. So it will easily charge 80-90%, maybe 95%? I don't know. It will NOT balance the cells. A separate charger would be needed for that. If you use the RV monthly, and it sits outside, then a solar panel would be good for balancing.
|
|
|
11-07-2024, 03:43 PM
|
#27
|
Senior Member
Join Date: Mar 2019
Posts: 1,054
|
I ditched my 3rd LP fridge in our 3rd RV after having enough of the unreliable operations we had with all 3!
We purchased a 12V GE, and only one 100 AH AGM, 200w of solar and a portable 3,000 WH so-gen. It’s been 2 plus years! We couldn’t be happier. We don’t dry camp much, maybe one night here and there, and I have enough power to run everything!
|
|
|
11-07-2024, 10:09 PM
|
#28
|
Senior Member
Winnebago Owners Club
Join Date: Mar 2011
Location: Fairfield, CA
Posts: 786
|
We've owned our 04 Journey for almost 15 yrs. It has the Norcold 1201LRIM. The original cooling unit failed about 5 years ago. I replaced it with a JC Refrigeration same style unit. It lasted about 3 yrs then developed a leak. Third time around, 18 mos ago, I swapped the unit with JC's 12V unit. It too also keeps the freezer at 0 and the box 38-40. I think it would improve if I had new seals but they aren't available w/o buying new doors which is outrageous. If this refer fails for some reason I would consider JC's 3 door refer which would fit with a few cabinet mods which is doable. That way, everything is new. We don't want a 110V refer because we camp mostly with hookups, and have just a factory small solar panel for trickle charging when unplugged.
Our biggest outing is Quartzsite every year dry camping for 2 weeks+. I carry a Honda 2000iu genny and run it during the day for a while to top off batts and the voltage stays up during the night with the refer running. I also use 4ea 6V lead acid batts.
Just my 25 cents of info.
__________________
Barry & Sue Miller("extended" RVer's, 6 mos + per/year) combined trips.
04 Journey 39K, C-7, 330 hp, towing: 13 Ford Edge AWD, or 19 GMC Canyon 4WD, ReadyBrake.
|
|
|
 |
|
Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)
|
|
Thread Tools |
Search this Thread |
|
|
Display Modes |
Linear Mode
|
Posting Rules
|
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts
HTML code is Off
|
|
|
|
» Recent Discussions |
|
|
|
|
|
|
|
|
|
|
|
|
|