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Lifelines To Lithiums
Changed the 3 house batteries in our 1996 Prevost XL40′ Liberty 12v Classic from 3 Lifeline agm 12v/250ah 160 lb 8D to 3 Renogy lithium 12v/200ah 60 lb 4D with Bluetooth. They are connected in parallel.Why switch? more usable AHs, 300 Lbs lighter, a lot longer life which equals less cost, they operate at a little higher voltage which is good for the 12v items/system, and shorter recharge time. I caught a good sale and paid about the same as I would for Lifeline agm. These have Bluetooth too.Battery area was better enclosed. Installed a 12v/12 watt heat matt at the end of each battery. The 12v source is the batteries themselves. The matts on/off power is controlled by a capillary tube type mechanical thermostat and 3 switches which are mounted on the wall in the first curbside bay just outside where the batteries are located and accessed. The battery racks and hold downs are designed for group 8D size, so spacers are required to keep the lithium 4D size batteries from moving around.Our Liberty “12v Classic” has 2 alternators. A 12v “house” alternator and a 24v “chassis” alternator. The 24v has nothing to do with the house batteries. The 12v is a DelcoRemy 12v/145 amp unit. Everything I’ve read and/or heard on the internet says to expect alternator problems when recharging lithium batteries with an ole school alternator like ours. So far, it’s doing a good job of recharging the lithium batteries. It has never charged at greater than 50 amps and 13.7 volts. I’ve seen no reason for the alternator to overheat. I see no reason for the battery BMSs to disconnect from the alternator.I don’t think it’s a good idea to have (2 different battery chemistries) the lithium house batteries connected to the genny lead acid battery except when the Detroit ignition switch is on. So, the battery isolator that connects the house batteries to the lead acid genny battery was removed. Liberty set it up that way to charge the genny battery via the house batteries. In place of the isolator, I installed a continuous duty normally open solenoid that’s activates closed via the Detroit ignition signal. Now, when the Detroit is running, house and gen batteries are charged thru “the solenoid” with the 12v house alternator. When the Detroit is off and the genny is running the gen battery stays charged via the little alternator on the genny. The house and genny batteries “aren’t” connected except when the Detroit ignition is switched on. The genny battery will absorb any spikes that might occur. I never run the genny at the same time the Detroit is running.When the Detroit isn’t running, the house batteries may be charged by the 2 Magnum Energy MS2812 2800 watt inverter/chargers via shore or genny 120v power. They are not capable of powering the cruiseAirs. Their remotes come pre-programmed for various battery chemistries. Lithium is not one of them, although AGM#2 comes really close. Magnum Energy provides two other methods for the user to install charging profiles, CC/CV and Custom. I have programmed and used both of these other charging profiles so as to be compatable with my lithium batteries. Time will tell what works best for us.The Magnum Energy inverter/charger temperature sensors were unplugged. They are no longer needed because lithium batteries don’t get temperature compensated charging. But understand, lithium batteries are NOT to be charged when their temperature is 32*f or less. These batteries can be discharged at temps as low as -4*f, and stored at temps as low as -13*f. I installed a wireless remote temperature sensor/transmitter in the battery area so I will always know what the temp is where they’re located. -
19 Replies
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You can charge Li batteries below 30F, but the rate of charge is limited. The battery manuals stipulate the allowable rate.
Since an engine alternator cannot have its output adjusted the simple solution is to keep the batteries above 30F.
They still cannot be justified solely by economics, but when all Li benefits are taken into consideration they start to make sense. I would not be concerned about charging two different battery technologies. My Li batteries and the AGM batteries they replaced have similar charging protocols so my AGM generator battery and the Li house batteries see the same charges.
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Nice job Don, I think you covered all the bases, time will tell.
Why did you choose 4D at 200 amp hrs vs 8D at 300 amp hours? I assume dry camping isn’t your normal bus use. If replacing the 3 Liberty Lifelines with 3 of the 300 amp hr Relion’s it would give some serious battery power. Just curious, I deal with these scenario’s often. The down side is people usually buy the fact of drop in and there is no such thing. There’s many variables that need addressed.
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Jon, the BMS in these batteries at 44*F triggers a low temp warning via Bluetooth. At <32*F the BMS doesn't allow charging. The temp has to rise to 41*F before the BMS will allow charging again. See pages 13 & 14 of this MANUAL LINK for all the various warnings and protections provided by the BMS in each of my batteries.
Tom, nobody makes a comparable battery in the 8D size at the price point I got these at. No, we don’t do much boondocking. We run the genny a lot. -
Don, we have two different battery specs. While temps determine charging protocols my Relion batteries allow cold temp charging and with my battery enclosure and temperature regulated heater I am able to keep the batteries warm enough to be able to spank them with full charging power any time. The only thing I ever worry about or monitor is voltage just to monitor the charging process. The only reason I do that is my Outback inverters go into “silent” mode after bulk charge and I just want to verify the inverters periodically restore the float charge when required. More from curiosity than need.
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The difference in specs is in the BMS part of the batteries. I like the extensive warning and protection that the BMS in our batteries provide. Bluetooth is a bonus.
Cost to our door was equal to or less than that of Lifelines. Availability was immediate, Lifelines were on back order. This made perfect economic since.Our house batteries live in the bowels of the bus. I’ve improved how well they’re insulated from temperature swing influences. I’m monitoring the battery area temperature. There is about a 5*F swing at the batteries when the outside air temp swings 35*F. On a recent morning it got down to 24*F here. The battery area didn’t drop below 46*F. Even though I added automatic thermostat-controlled heat for the house batts, there has been no need for it. Not even close. But never say never. -
Don: “I’m monitoring the battery area temperature.”
What are you using to monitor that temperature? What devices or systems or remote readouts? TIA!
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Since we Liberty owners lack immediate access to our batteries it is important we have a means to see and control their environment. On mine the battery area is automatically temperature controlled with a kick in temp of 40 and kick out temp of 50 using a remote thermostat with a display. It is always powered, with the energy coming from the batteries themselves.
Newer Relion batteries can be provided with BMS controlled internal heating. Mine do not have that feature hence my external heat and control.
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Acurite multi-sensor wireless thermometer w/3 remotes.
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What is the hi temp limit when they stop accepting a charge? Most are 113 to 118 F. How do you keep it below this when in hot country?
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Mikee, my batteries stop excepting a charge @ 131*F.
Here’s the manual for my batteries. See pages 13 & 14.
I don’t see that being a problem with our setup. Like I said previously here, our batteries are buried in the bowels of the bus, and I’ve enclosed and insulated them away from outside influences.
If it was a problem for someone, the batteries could be located to the bus interior (under the couch etc), or a duct installed to direct a little OTR AC air and/or CruiseAir air to the battery area.
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Relion’s are max charge temp 113 and BMS cut-off at 176
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This was the first real world dry camping test of the lithium house batteries. I installed them last Dec.Before leaving they were fully charged via CC/CV (constant current/constant voltage) that I previously programmed into the dual Magnum inverter/chargers. Drove 6 hrs to our destination with both inverters “ON” so the refrigerator etc would function properly. Their charger functions were “OFF”. Generator was off. The liberty installed 12v ACDelco alternator kept the house batteries fully charged. The 12v alternator never had to put out more than about 25 amps on the way there. Once there (Friday evening), the lithium house batts were never recharged. Two days later, Sunday morning, the batteries were at 12.7v when we started the 6 hr drive home. The 12v house alternator recharged the lithiums on the way home, never putting out more than 60 amps.We admittedly didn’t spend all our time at the bus while dry camping. We were off having fun with friends.What was used off inverters:a – 120vac aux compressorb – 120vac coffee maker 2 morningsc – 120vac refrigerator/freezerd – 120vac microwave12vdc items we used:a – house lightsb – house water pumpI’m a happy camper. IMO, our previous Lifelines couldn’t have done this, even when new.
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Running Microwave on battery is impressive. Lithium does not suffer from Peukert Effect which among other factors makes them quite attractive to me.
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What! Every bus out there can run microwaves on batteries, that’s a standard since the late 80’s. Doesn’t matter if wet cell or AGM, battery bank capacity with properly sized inverters get the job done. Surely your Phaeton with (6) 6v golf cart batteries in parallel/series will run your microwave.
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