Lithium battery
Printed From: R-pod Owners Forum
Category: Non-pod Discussion Forums
Forum Name: Mods, Maintenance, Tips and Tricks
Forum Discription: Same as podmods, just... not for pods
URL: http://www.rpod-owners.com/forum_posts.asp?TID=15103
Printed Date: 05 May 2024 at 3:10pm
Software Version: Web Wiz Forums 9.64 - http://www.webwizforums.com
Topic: Lithium battery
Posted By: Jackash
Subject: Lithium battery
Date Posted: 09 Jan 2022 at 5:25pm
Has anyone got any experience or advice for switching over to lithium battery for my RPod 195?
-------------
Jackash
|
Replies:
Posted By: StephenH
Date Posted: 09 Jan 2022 at 5:51pm
Not in a 195, but in our 179, you can read about my conversion in my mods (see link in signature).
-------------
StephenH
Happy is the man that findeth wisdom,...
http://www.rpod-owners.com/forum_posts.asp?TID=7712 - ouR escaPOD mods
Former RPod 179
Current Cherokee Grey Wolf 24 JS
|
Posted By: Jackash
Date Posted: 09 Jan 2022 at 10:51pm
Thanks. Tons of info there.
-------------
Jackash
|
Posted By: offgrid
Date Posted: 10 Jan 2022 at 8:20am
The keys with a lithium conversion are:
place the battery in a heated location, never charge a Lithium battery below freezing temps.
the battery must have a battery management system (BMS) that equalizes cell charge voltage and protects the battery from overcharging. The BMS should come with the battery and is typically internal.
Convert and/or reconfigure all charging sources for Lithium battery use. Those include the on board Ac/DC charger, alternator charging from the tow vehicle, and solar charging if you have that.
The on board lead acid battery charger can be swapped out, and most modern solar charge controllers have a Li setting.
Generally the alternator charging is the most complex to convert. You do not need to run a separate charge circuit, the +12V pin on your 7 way connector will work. You need to run that into a DC/DC converter located in the trailer, before that wire connects to anything else in the trailer. The DC/DC converter should be sized based on the ampacity of your 12V trailer supply. That will typically have a 3O amp breaker so a 20 amp converter would be a good choice.
You will either need to disconnect your 7 way whenever you stop for more than an hour or so or set up that circuit with a relay so it's switched off when the ignition is off (some already are), otherwise the converter will happily continue to charge the Li battery if it is low,discharging your tow vehicle starting battery in the process.
As you can see, much of the cost and most of the work is involved with the charging sources and wiring, not with the Li battery itself, which is getting pretty inexpensive now.
-------------
1994 Chinook Concourse
1995 RV6A Experimental Aircraft
2015 Rpod 179 - sold
|
Posted By: StephenH
Date Posted: 10 Jan 2022 at 8:40am
|
+1. I chose to run a separate circuit because I thought the original charge wire from the Frontier was inadequate and I wanted to put a battery isolation relay in. I probably could have used the regular wire and just disconnected it to run the DC to DC charger as it does appear that the Frontier would have a relay that is timed to cut that circuit off after a few minutes. I did not realize that at the time. I still would have had a fair amount of work and needed the DC to DC charger anyway.
When I first tried this, I did not have the wiring correct which meant that the battery was trying to charge itself. Since there is no "free" energy or perpetual motion, it was bound to fail. Just be sure to understand how the wiring is run so you don't end up making the same mistake that I did.
-------------
StephenH
Happy is the man that findeth wisdom,...
http://www.rpod-owners.com/forum_posts.asp?TID=7712 - ouR escaPOD mods
Former RPod 179
Current Cherokee Grey Wolf 24 JS
|
Posted By: Jackash
Date Posted: 10 Jan 2022 at 10:05am
Thanks for all the info and advice. Think I am going to pass for now. What about the “AGM” type batteries? Anything special to add one of those or is just a straight swap?
-------------
Jackash
|
Posted By: StephenH
Date Posted: 10 Jan 2022 at 11:13am
They also are not exactly a straight swap. They do have a little different charging profile than a flooded battery. Also, the analysis I read was that the extra cost of an AGM battery was not really worth it. Your best "bang for the buck" is in two 6V GC2 batteries wired in series to give you 12V. The down side is that the two batteries together will weigh 120 lbs or more.
-------------
StephenH
Happy is the man that findeth wisdom,...
http://www.rpod-owners.com/forum_posts.asp?TID=7712 - ouR escaPOD mods
Former RPod 179
Current Cherokee Grey Wolf 24 JS
|
Posted By: offgrid
Date Posted: 10 Jan 2022 at 1:59pm
+1. The AGMs (absorbed glass matt) batteries are quite a bit more expensive but perform no better than flooded deep cycle batteries. They are also more sensitive to overcharging (because you can't just take off the caps and add distilled water) so you have a bit lower peak charging voltage. They do have one advantage which is lower maintenance so if you can't bring yourself to check the water level every month or so by all means spend the extra $$$ for the AGM's.
-------------
1994 Chinook Concourse
1995 RV6A Experimental Aircraft
2015 Rpod 179 - sold
|
Posted By: TheBum
Date Posted: 11 Jan 2022 at 4:39pm
"Drop in ready" lithium batteries will charge just fine at lead-acid voltage/amperage levels. They just won't fully charge, which has some merits for extending service life. I just purchased a Battle Born lithium battery for my 196.
-------------
Alan
2022 R-Pod 196 "RaptoRPod"
2022 Ram 1500 Lone Star 4x4
Three cats
|
Posted By: offgrid
Date Posted: 12 Jan 2022 at 2:29am
ummm.
Battle Born recommends using a high quality ac charger specifically configured for Li batteries. The key concern is not undercharging, which won't hurt a Li battery, (just limits useful capacity) but overcharging during bulk or equalization mode. That is dangerous.
My WFCO failed and took my flooded golf cart batteries up to 16V plus volts. No harm done to those batts, just excessive water consumption, because I caught it before the plates were exposed. But that would be very harmful and dangerous for a Li battery. Battle Born's BMS is designed to prevent that level of overcharging but after my experience I wouldn't want to count on it as the sole line of defense against overcharge.
Battle Born also recommends using a DC/DC converter for alternator charging. They are master distributors for both Progressive Dynamics (ac chargers) and Victron (solar charge controllers and DC/DC converters) so you can get all your hardware from them if you want. PD and Victron both make good products for this application.
I'm not recommending Battle Born as a source though, they are overpriced for my budget. I'd personally go with StephenH's lower cost approach. Either way will work fine, but you do need to take some care in a Li conversion. I wouldn't recommend just dropping a Li battery into an rpod without other modifications.
-------------
1994 Chinook Concourse
1995 RV6A Experimental Aircraft
2015 Rpod 179 - sold
|
Posted By: 0ttr
Date Posted: 16 Feb 2022 at 7:34pm
I bought an SOK battery with a Victron BMV-712 battery monitor with the shunt. I installed it in the empty space under the bench in the front of my 2013 r-pod 177. It charges fine with the shore power, but does not charge on from the alternator. I haven't had time to troubleshoot that yet. That said, the conversion was not difficult. I have a solar panel I've purchased, but I don't have a charge controller for it. I'm not sure how much of a priority it is for me to get the alternator charging working.
Before I changed to this battery I did drain my tow vehicle battery by forgetting to unplug it while boondocking one night. I know you can buy a 12v solenoid to fix that but I haven't prioritized that for now.
Honestly, having the Victron monitor is really nice to know exactly what state my battery is in and what the draw on it is at any given time, on top of the fact that it just holds so much more power. I can check that on my phone. I haven't had problems using the battery in winter. Obviously you can't charge below freezing. With the battery inside that's not a problem unless it is awfully cold. SOK batteries have a handle and you can pull it, which I do. It stays in my house when I'm not using it. They weigh half as much as a lead acid battery.
|
Posted By: StephenH
Date Posted: 16 Feb 2022 at 8:11pm
|
Hello OTTR,
You will not be able to get it charging from the alternator. The alternator is set for lead-acid batteries and will not output the higher voltage needed to charge the LiFePO4 battery. What you need is a DC to DC charger. The alternator will power the DC to DC charger which can be set to boost the voltage and charge the LiFePO4 battery. You may wish to read my mods topic to see what I did and the various discussion about it. See the link in my signature if you do.
I also installed an isolation solenoid to prevent that from happening. That is in the mods topic as well.
I hope this information will help you. If you only have one panel, then a simple, inexpensive PWM controller will likely be sufficient. I have a renogy 100W folding suitcase. It came with a controller. So far, it has worked well when there is bright sunshine.
-------------
StephenH
Happy is the man that findeth wisdom,...
http://www.rpod-owners.com/forum_posts.asp?TID=7712 - ouR escaPOD mods
Former RPod 179
Current Cherokee Grey Wolf 24 JS
|
Posted By: TheBum
Date Posted: 18 Feb 2022 at 10:58am
|
Power from the TV will charge a lithium battery with a built-in battery management system to a certain extent. It won't fully charge because the voltage isn't high enough.
I'm in the process of installing a Battle Born 100Ah battery in my 196 after I let my GC2s get a little low on water and they weren't performing as well as I thought they should. I'm tired of having to monitor cell water levels, so I made the jump to lithium. I went with Battle Born because they were reasonable compared to other options and they're assembled in the US (Nevada). I'm swapping the innards of my WFCO converter with a PD-4655LI.
-------------
Alan
2022 R-Pod 196 "RaptoRPod"
2022 Ram 1500 Lone Star 4x4
Three cats
|
Posted By: StephenH
Date Posted: 18 Feb 2022 at 1:13pm
|
Charging systems in tow vehicles are not the same as when it was a simple voltage regulator. To get better mileage, the charging systems in new vehicles also use a charge control system that is barely adequate to charge the vehicle's battery fully, let alone trying to charge a LiFePO4 battery. I found when we first got our LiFePO4 battery and tried to use it with the Frontier's charging system that I would end up with less charge than when I started. One overnight stay and then driving several hours the next day and the battery ended up even lower in charge. I think the LIFePO4 battery's charge was fooling the Frontier's charge system into thinking the truck's battery was charged when in reality, the LiFePO4 battery was feeding back into the truck. That is the reason I say that you need a DC to DC charger if you intend to run the LiFePO4 battery. Of course, if your tow vehicle is an older one that uses a simple voltage regulator, you might be okay. However, any recent vehicle is likely to have issues.
I also recommend a battery isolation solenoid to keep the trailer's battery isolated from the tow vehicle's battery when stopped, even if you don't disconnect.
-------------
StephenH
Happy is the man that findeth wisdom,...
http://www.rpod-owners.com/forum_posts.asp?TID=7712 - ouR escaPOD mods
Former RPod 179
Current Cherokee Grey Wolf 24 JS
|
|