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 > Your search for posts made by 'phemens' found 53 matches.

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  Subject Author Date Posted Forum
RE: LiFePO4 - SOK or Renogy.

Hi Almot, I’m wondering if you made a decision and how it worked out. I’ve been looking at the Renogy Smart Batteries but am discouraged by the terrible reviews of Renogy Canada. People on BBB and Trust Pilot say to avoid this company because the service is as bad as bad can be. The topic has drifted far, far away - as it often happens on this Tech Forum, which makes it more interesting. But since you brought back my mundane initial quest for a gold nugget in the pile of Chinese, er... stuff ;) - yes, I made a decision and bought Lynac Lithium as suggested by some member: Thanks. The Lynac 100AHs are out of stock right now. Preorders only. I subscribed to your testing thread to learn from your experience. The fact that he answered your question immediately is a good sign. My wife recently got a CPAP. We were going to power it off grid with a so-called solar generator but figure the money might be better spent upgrading the house battery in our rig. I was the one to recommend them. I was their first RV customer 3 years ago and I've kept in touch with the owner on various questions during that time (plus a couple of additional batteries), he's always been very responsive and transparent. So far after 4 seasons the batteries are holding up well, no discernable loss of capacity or issues. If I were to do it all over again, I would probably build my own today, as there is much better reliable reference information available on the internet, and a plethora of reliable sources for the cells. Also much more comfortable with the technology and would know what to build for. All that being said, as a first time buyer I would repeat my purchase with them. With the battery bank we have and the solar, we don't worry at all about energy conservation - the inverter is always on, residential fridge runs 24/7 and we freely use TVs, CPAP, etc. without concern. That was exactly the use case I was aiming to meet and for us LiFePo4 was the right solution.
phemens 05/05/21 11:09am Tech Issues
RE: Basics of Lithium conversion... I'm lost!

phemens, Nice post on aluminum heat sink dissipation. I think the trust of the recent posts is how to keep the batteries warm in cold weather. (which is what keeps me from using them) Yes, but I think that's largely overstated as an issue for 95% of people that are the potential target market. Your use case evidently is extreme, which means that chemistry isn't for you! In my case we camp on a remote piece of property without any services and need the batteries & solar to function continuously to keep the residential fridge going 24/7. We're also not there for several days at a time, so I need something that is relatively fool proof. There are a few weeks in the spring and fall where the temperature drops enough that if I didn't warm the batteries, the Victron sensor would prevent the MPPTs from charging (I set the cutoff for 5C, which is conservative). The warming mat and insulation see me through but I can't speculate on whether it would be sufficient for much colder temparatures. Were that the case I would probably opt to add a beefier heater and fan.
phemens 04/27/21 06:06pm Tech Issues
RE: Basics of Lithium conversion... I'm lost!

do you use a tiny computer fan or anything to blow the heat around or are you just using the heat radiating off the alumium base? Steve If using a thermostat controller like mine it must be placed to measure the heat in the batteries, not the surrounding air which would heat up quickly and perhaps shut down the heater before the batteries reach a good temp. If you look at my diagram and read the text, I placed the temp sensor between the 2 batteries which are tight together and below the top. I use a Victron shunt connected directly to one of the battery terminals. No fan, aluminum dissapates heat for all of the batteries.
phemens 04/27/21 01:00pm Tech Issues
RE: Basics of Lithium conversion... I'm lost!

https://diysolarforum.com/threads/lifepo4-battery-warmer-install.14485/ This thread shows how to install warming pads and a thermostat controller for LiFePo4 batteries. Mine is shown on page 5 for my Class B. Works great. thats interesting, a lot of them seam to wrap the batteries in insulation tight, then have the pad stuck to the side. wouldnt it make more sence to have that insulation an inch or two away from the battery so you could get a bit of air movment and use less pads to heat more batteries? just thinking here so if it has been done and didnt work I would be curious as to why. seams to me if you have the space to put say 2 or 3" of good insulation with sy a 2" air gap between the batteries and the inside of the insulated box and say a tiny ultra low draw fan to cirulate the air, you could probably heat several batteries with one heating pad and cut the amp draw for that purpose. of course this would depend on the space you have also I guess. Steve That's exactly what I do. I have a single waste tank heater placed under 6 LiFePo batteries (with a thin sheet of aluminum to spread the base), with 4 inches of foam insulation cased around the battery box. There's about 3 inches of gap between the batteries and the foam. I checked this weekend and the temp at the battery terminal according to the Victron shunt was 8C, ambient outside temp was -3C. Works well for my purposes, we don't camp in extreme cold weather but do in the fringe seasons.
phemens 04/27/21 06:17am Tech Issues
RE: RV Roof Tape

Can't speak for Extreme White RV Roof tape, but I've used Eternabond on all my RVs and been very happy. Good preparation and planning is key, as you mentioned making sure all surfaces are clean and having the right tools (one of those rollers for laying down lineoleum is very useful for getting enough pressure). Start slowly and make sure you correct your line as you go, once the tape is down it is down, and I've had plenty of creases. It doesn't need to look pretty (but nice if it does), as long as it covers all the seams. Don't forget to do any slides too.
phemens 03/27/21 05:37pm General RVing Issues
RE: Lithium batteries and new solar charger

Your two 100 LFP will actually have 80 usable each so 160 not 200 to compare with the 260. (you don't normally go below about 20% DOD) Your controller is a 12/24 but being PWM that only means 24 if the batteries are also 24. To go 24 panel and 12 battery, you must have an MPPT with its buck converter that PWMs don't have. Depends on whether the batteries are 'true' AH or not. The last LiFePo4 battery I bought was rated as usable 100AH, so in reality 120AH.
phemens 03/22/21 07:34am Tech Issues
RE: LiFePO4 - SOK or Renogy.

He helped me figure out all the correct settings for my MPPTs and charge controller. Lynac Lithium As an aside, the storage of LiFePo4 batteries at 50% is meant for long-term storage (i.e. over the winter), not a problem at all if it's a matter of weeks. I'm curious what he suggested on controller settings. I see manufacturers labeling their controllers "Lithium compatible" while they are just regular 3-stage controllers with Bulk, Absorb and Float, and Absorb is often fixed 60-90 minutes. My impression has been that Lithium cells don't need Absorb for any substantial period of time. Odd controllers like EcoWorthy that switch to Float in a few seconds after hitting Absorb, is what it needs. I think Float won't hurt much, especially if you set it below BMS cut-off, so it would just start Bulk when voltage drops below Absorb. Yes, 50% SOC is for long term storage. When you're going to use it in a matter of days or in 2 weeks, you can charge it fully. It's a sliding scale, the more paranoid you are about it the better the chances are that it would live up to the promised 3000-4000 cycles. In a nutshell, I'm using a 3000w all in one Samlex unit, with Victron MPPTs for the solar. Here are the settings he gave me for the Samlex (settings essentially same for the Victron, but with temp cutoffs): Battery type= 1 Lithium Charging profile 3=2Stage Type1 Absorb Exit Amps=0A Absorb Time=1 min Floating exit=12.00V Equalize-4stages 0=No LV cut off time = 1200 sec LV detect time=10 sec Batt low voltage=12.00V Low volt alarm=11.50 V Reset Voltage=12.60 V Batt over volt=14.40 V Compensate= 4 mV/C/C Floating voltage=13.00V Equalize voltage=14.00V Absorp voltage=14.20V
phemens 03/01/21 07:58am Tech Issues
RE: LiFePO4 - SOK or Renogy.

If you want to buy in Canada, I bought from this company 2 years ago (total of 6 100ah batteries), and dealt with the guy who runs the outfit, very accomodating and full of info (he's an electrical engineer). He helped me figure out all the correct settings for my MPPTs and charge controller. Lynac Lithium As an aside, the storage of LiFePo4 batteries at 50% is meant for long-term storage (i.e. over the winter), not a problem at all if it's a matter of weeks.
phemens 02/27/21 11:20am Tech Issues
RE: RV Lithium Lite & Lithium Super Upgrade Systems - Mike Mas

phemens, The reading I've done (which may be incorrect) suggest low slow charging may be possible at -20 c (-4 f) Tonight it will be -33c here. Yes, I've heard that as well. My use case is really on the borderline of the threshold for regular charging (getting down to below 0c occasionally, with risk of battery core temp falling into that 'danger zone'), and that's for a couple of weeks at the end of the season (maybe longer is we start extending). Since we're not there to make adjustments during the week, the safest option for me is the waste tank heater running all the time. At 6a/hr, I only really get a drawdown after the sun doesn't send enough juice to the solar panels, so maybe 14 hrs which is 84 ah to recover, which is more than acceptable given my battery reserves. While we're away apart from the heater, there's the residential fridge and usual parasitic draws, so the system keeps up without breaking a sweat.
phemens 02/06/21 09:43am Class A Motorhomes
RE: RV Lithium Lite & Lithium Super Upgrade Systems - Mike Mas

Retaining capacity in LiFePo4 batteries isn't the issue, it's restoring the charge, that's where you'd need some kind of heating setup to maintain core temp. You can safely discharge at high efficiency in cold weather (I believe it's efficiency is substantially higher than wet cell).
phemens 02/05/21 07:26am Class A Motorhomes
RE: Lithium Titanate

Easy answer for me. Expensive batteries give me peace of mind. With Covid, our trailer is parked for 3 seasons on a piece of property we bought (to camp on because campsites were closed last summer and for eventual retirement). With plenty of solar and a big, light battery bank, I can keep a residential fridge running full time with no worries and plenty of power for days if there's no sun - something I can't do with a generator since we're not there full-time. When we get back on the road (who knows when?) we're fully self sufficient and well within weigh limits (something I can't say about my previous battery bank of 3 huge Rolls 210a 12 volters...).
phemens 02/01/21 06:23am Tech Issues
RE: SiO2 Batteries

What is your intended use? Boondocking. I have 220W of solar with a MPPT charger. No AC appliances. I have two 100AH deep-cycle AGM batteries now. I am attracted by the LiFePo4 batteries for their reducted weight and current capability but not their need for a special charger. The SiO2 eeidently can use a standard charger. If your charger is programmable, the settings for LiFePo4 are not complicated. I'm a little puzzled though - if you're going to invest significant $ in batteries, a small investment in a new charger (if needed) is a problem?
phemens 01/27/21 06:31am Truck Campers
RE: Built-in Genset on 2021 F-150

From what I can tell, it's only available as option on the F150's. Any news or info on availability for the Super Duty range?
phemens 01/11/21 06:20am Tow Vehicles
RE: All in one solar / shore converter charger

I have the Samlex 3012, it does everything you're asking it to do, and it's built like a tank, solid components that IMO are less likely to fail than individual devices (charger, inverter, etc).
phemens 01/09/21 10:01am Tech Issues
RE: Heating pads

The one I use for my battery bank is a waste tank heating pad and it draws 6 amp at 12v. It is intended I believe for 49 gallon tanks.
phemens 01/07/21 06:30am Do It Yourself Modifications and Upgrades (DIY)
RE: Lithium heating pads

A couple of things to think about before adding heaters to your LiFePO4 batteries: 1. Are you really 'protecting' them? Many (most?) LiFePO4 batteries have a low temperature charge cut off built in to the BMS, so they protect themselves and won't accept a charge below a certain temperature (I think it is about -3C for Battleborn). The downside of not having a heater is that you may miss out on some charge opportunities when it is very cold, not that you will damage the batteries. 2. How much energy will heating the batteries use? Several of the solutions presented here keep the batteries MUCH warmer than they need to be. There is no advantage in heating the batteries to 20C and it wastes energy. You also only need the batteries to be heated when charging, they can be cold while discharging. It is far more (electrical) power efficient to heat your batteries with what ever heater you use to heat your living space - which I assume you keep above -3C. 3. There are situations where you really do need to heat the batteries - but they are less common than most folks think. In the case you do need heat then external heat pads are the best option. While internally heated batteries seem like a good idea, if you us a battery monitor to track things (eg a Victron BMV) the internal heaters will throw everything off as the current for the heaters cannot be accounted for by the monitor. To your point 1) & 3), that's exactly why I have the heating pad, to permit charging in conditions where normally the BMS would prevent it. Admittedly for me this is in cases where it's marginal (i.e. the battery temp is already close to the cutoff @ 5-8 C according to my Victron battery temp sensor) but I never reached it. Better safe than sorry for me, having the capability to charge when I want was important to me - we leave our RV at a remote site off grid and keep the residential fridge running, so I need to ensure the batteries stay charged. For point 2), the heating pad draws a steady 6 amps @ 12v. For me, since I have more than ample capacity, I don't worry about that too much, the solar tops batteries up usually before noon. Batteries are in the front compartment and it is not ducted for heat, and we rarely run the main heater, we prefer to use a Mr. Buddy to cut down on noise. (we only run it when we're up, not overnight).
phemens 01/07/21 05:58am Do It Yourself Modifications and Upgrades (DIY)
RE: Moving LiFePo4, Rewire or run Long Extensions?

^Like I said, no harm, no foul. I’m sue your setup works great. It’s just not necessary to use wire that size. Starter motor on a diesel pickup pulls 450+ amps through 2/0 wire, for comparison. More so posted for others who don’t have the knowledge, that they do not think 4/0 welding cable is required for this setup. Cheers Happy New Years ! wow, I dont know if I would use 4/0 for anything but welding haha. I dont have a situation where I have to carry 400plus amps up to 30 feet away. but ya if you got it use it. Every wire gauge calculator I've tried recommended 4/0 cable for my setup, and my lengths are nowhere near 30ft. From the battery bank to the bus bars is 3ft, and from the bus bars to the 3000 W inverter is 5ft. At 300 amps for a couple of minutes (say running the microwave), those wires heat up fast. I'm not going to gamble an expensive set of batteries for a couple of bucks.
phemens 01/06/21 05:56am Truck Campers
RE: Moving LiFePo4, Rewire or run Long Extensions?

When installing my system I used 4/0 welding cable with equal runs connecting 4 batteries ( 450 ah ) and a 2,000 watt Magnum inverter. Fuse the + at battery. All terminals are both crimped and soldered. Estimate your needed run and buy the cable in one piece and cut to desired lengths. Simple and minimizes loss. 4/0? OMG, why? Presume you had it laying around and then thus more economical than buying adequate but much smaller cable? Mine is wired the same way, and nope, didn't have 4/0 just lying around. Depending on the draw (microwave, etc), you can pull several hundred amps off the batteries in short bursts - I've seen in excess of 300. Much smaller wire will not be up to the task.
phemens 12/28/20 10:10am Truck Campers
RE: Moving LiFePo4, Rewire or run Long Extensions?

Thanks for the comments and suggestions. I think I need to clarify a few things as a few of the suggestions seemed to focus on the wrong issue in my opinion. What is unique about this camping experience is our twin baby girls that required us to heat their bottles multiple times a day and to keep the furnace running at night because at their age you can't cover them in blankets. The bottle warmer pulls ~300w for 10 minutes 4 times a day. The wife's coffee was ~700w for about 4 minutes each morning. Finally, we have running the furnace in the evening which was ~100w for about 5 minutes but cycling probably one to two times an hour from midnight till 6am. The 200w of solar is usually fine for our "pre-baby" camping needs during the summer but with these new needs and less sunlight in the winter months, just was not enough to get the battery topped off each day. Next year we won't be doing bottles or need to run the furnace as aggressively so those factors will go away. The coffee pot we can run the genset for if really necessary though I think without the other two factors, the coffee pot isn't going to be an issue. The point of my post however is that what I did discover is that the LiFiPo4 battery when it gets cold will limit it's charge rate. This was a bit of a head scratcher the one morning when we ended up with a dead battery so I started the truck around 6am (~20 degrees outside) in order to be able to run the furnace and put some charge back into the battery. I found the battery was only charging around 3 amps when I have a 20amp DC to DC charger. It took me a while to realize it was the BMS on the battery limiting the charge because of the temperature. Moving the battery inside is just a project I am considering because I have a pretty optimal location for it that would eliminate the cold factor. In normal use I don't think I really need to add more battery capacity but will eventually add another 200w (for 400w) total of solar power. I might also replace the furnace with a more efficient two speed unit as well. Just FYI, there's an active thread on heating pads for LiFePO2 batteries to keep them in the 'green' zone for cold weather charging. This presumes you might consider keeping your batteries 'outside'.
phemens 12/27/20 02:51pm Truck Campers
RE: Lithium heating pads

My battery is 10.5x20 you think I can stick the pad right to the bottom and do you think I would have to enclose battery. It’s great to converse with someone that has done this I think if you centered it you'd be fine. My footprint is considerably wider and it does fine with the aluminum sheet. As far as enclosing the battery, it depends on where it is located and to what temp you expect to use it. The heating mat can reliably keep the battery temp a minimum of 10C above ambient (at least from what I've observed in limited testing so far). I use foam insulation because they're located in the front storage compartment that has openings for the landing gear and gets quite cold. The batteries have considerable thermal mass, so it shouldn't take much to keep them in the acceptable temp zone with the heated pad. I'm probably veering on the other extreme of precautions, but I want to protect my investment. I think a good temperature sensor on the batteries is a must for this.
phemens 12/22/20 08:19am Do It Yourself Modifications and Upgrades (DIY)
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