pianotuna
Regina, SK, Canada
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Joined: 12/18/2004
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Stir thanks for the link.
I'm glad you posted some of the details. I can't read what ever language they have. They are close to my needs but..close only counts in horseshoes and curling.
I have done more than a few 10 day trips where the daily high was below -30.
* This post was
edited 11/03/23 06:56pm by pianotuna *
Regards, Don
My ride is a 28 foot Class C, 256 watts solar, 556 amp-hours of Telcom jars, 3000 watt Magnum hybrid inverter, Sola Basic Autoformer, Microair Easy Start.
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StirCrazy
Kamloops, BC, Canada
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Joined: 07/16/2003
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pianotuna wrote:Stir thanks for the link.
I'm glad you posted some of the details. I can't read what ever language they have. They are close to my needs but..close only counts in horseshoes and curling.
I have done more than a few 10 day trips where the daily high was below -30.
well, that's why it is in Chinese and English. you keep fixating on the outside temperature. that has nothing to do with whether the batteries will work or not for you. well, it has an influence. It's the actual battery temperature that matters, as in the internal temp. So, with a BMS that has a built-in heat control and having the batteries in an insulated space (even one that receives heat from the rv) you would have no problem. You could have the BMS heat the internal temperature of the battery to -30 then run the furnace. As you start using the battery, they make their own heat also which warms them up even more. before I moved my 280AH batter to an interior place in my camper I had it in the uninsulated exterior storage that gets pretty darn cold and at -10C (nighttime temps) the internal temp of the battery was still above 5C so I didn't have any issues as the act of running the furnace and lights was enough to keep the battery warm. Now that it is inside the camper there is even less of an issue as it is only cold when I first go somewhere and being able to discharge at 0.25C at -30C is more than I will ever need to start the furnace and warm everything up.
2014 F350 6.7 Platinum
2016 Cougar 330RBK
1991 Slumberqueen WS100
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pianotuna
Regina, SK, Canada
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stir find me an LifePo4 that works reliably at -40 with no "self heating". The only one I know of is Lithium titinate which is way beyond my budget. (at the time $1800 for a single 100 amp-hour)
I'm glad your choice works well for you.
SiO2 are a much better fit for me except for cost.
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Itinerant1
Itinerant
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Joined: 05/23/2017
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StirCrazy nice size battery bank. The only thing I'm going to disagree on slightly is the cells heating up.
As I have posted before I fulltime in the 5th wheel living off of 500ah lfp batteries and 1,280w solar. This setup has been going for 7 years 7 months now in everday use never been turned off. My longest strech of consecutive boondocking was 1,017 days. As of today we have hit a 2 year stretch of consecutive boondocking.
The only time I've seen the cells heat up is when using the gen/ inverter charger and charging at 100a for more than anhour and then the cells only get 10f warmer. Any other time whether using microwave or other appliances the cells might climbed a dregree or so but nothing enough to make a difference.
My batteries, inverter, SCC is all in the front compartment of the 5th wheel. I have used foam board insulation on the walls. Used Reflectixs, foam board, 1/2" rubber mat on the floof of compartment and tapped into a heat duct above the batteries and dropped a tubedown towards the battery. This has made the biggest difference keeping the batteries warm in that compartment. I was just in Utah for a few days of night times of high teens and daytime of upper 40s. Cells were at 46-55f. Me personally that's as cold as I like it and have moved further south now for winter.
If I were somewhere that I couldn't run from the extreme cold the batteries would be in the 5th wheel somewhere staying as warm as me.
Keep us updated on the build. Thanks![[emoticon]](http://www.coastresorts.com/sharedcontent/cfb/images/smile.gif "smile")
12v 500ah, 20 cells_ 4s5p (GBS LFMP battery system). 8 CTI 160 watt panels (1,280 watts)2s4p,Panels mounted flat. Magnum PT100 SCC, Magnum 3012 hybrid inverter, ME-ARC 50. Installed 4/2016 been on 24/7/365, daily 35-45% DOD 2,500+ partial cycles.
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pianotuna
Regina, SK, Canada
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Stir I fixate on outdoor temperatures because I am not full time. So the RV has to go from cold soaked -34 F to living temperatures.
Therefore the batteries need to be fully functional in admittedly, extreme cold.
* This post was
edited 11/04/23 06:49pm by pianotuna *
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StirCrazy
Kamloops, BC, Canada
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Joined: 07/16/2003
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Itinerant1 wrote:StirCrazy nice size battery bank. The only thing I'm going to disagree on slightly is the cells heating up.
As I have posted before I fulltime in the 5th wheel living off of 500ah lfp batteries and 1,280w solar. This setup has been going for 7 years 7 months now in everday use never been turned off. My longest strech of consecutive boondocking was 1,017 days. As of today we have hit a 2 year stretch of consecutive boondocking.
The only time I've seen the cells heat up is when using the gen/ inverter charger and charging at 100a for more than anhour and then the cells only get 10f warmer. Any other time whether using microwave or other appliances the cells might climbed a dregree or so but nothing enough to make a difference.
My batteries, inverter, SCC is all in the front compartment of the 5th wheel. I have used foam board insulation on the walls. Used Reflectixs, foam board, 1/2" rubber mat on the floof of compartment and tapped into a heat duct above the batteries and dropped a tubedown towards the battery. This has made the biggest difference keeping the batteries warm in that compartment. I was just in Utah for a few days of night times of high teens and daytime of upper 40s. Cells were at 46-55f. Me personally that's as cold as I like it and have moved further south now for winter.
If I were somewhere that I couldn't run from the extreme cold the batteries would be in the 5th wheel somewhere staying as warm as me.
Keep us updated on the build. Thanks
ya that weird, I get about 8 to 10 degrees when its that cold in the camper. I supose some heat could hav been radiating from the wet bath shell into the storage space they used to be in. I know a lot of people I know in alberta just use a good cooler on there trailer tounge with a silicone heating pas that only comes on when it gets to 0 inside and they tell me when they are on their skidooing trips at -10 to -25C they hardly ever see the silicone heater come on.
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StirCrazy
Kamloops, BC, Canada
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pianotuna wrote:stir find me an LifePo4 that works reliably at -40 with no "self heating". The only one I know of is Lithium titinate which is way beyond my budget. (at the time $1800 for a single 100 amp-hour)
I'm glad your choice works well for you.
SiO2 are a much better fit for me except for cost.
which is exactly why I am surprised your even comenting on this thread, you have dmisitidly stated you will never have LFP as you won't make alowances to make them work by putting them in the conditiond space or other simple things, so why are you interested in a thread on how to build one, I am actualy curious.
actualy LTO has come down a lot in price you can get 45AH cells for 39 bucks each and it takes 6 to make a 12V battery. so you could do a 90AH battery for about 684.00 plus what ever your BMS for that costs.
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pianotuna
Regina, SK, Canada
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Stir I probably won't have SiO2 either. My existing bank may well outlast my ownership of my class C.
I know prices have dropped--but I want at least 500 amp-hours. That's over four grand.
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StirCrazy
Kamloops, BC, Canada
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pianotuna wrote:Stir I probably won't have SiO2 either. My existing bank may well outlast my ownership of my class C.
I know prices have dropped--but I want at least 500 amp-hours. That's over four grand.
yup they are expensive, and their curve isn't as closely matched as LFP for 12V, but they work. I just don't like the form factor they are available in as they are more work to mount and such.
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StirCrazy
Kamloops, BC, Canada
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so my replacement cell should be here today, but now I am faced with another disision which I am going to go to some of the other people that have LifePO4 batteries they have build them selves for their opinion.
JBD BMS (also sold rebranded as Overkill) are a good BMS. I have been happy with the one I have in my other battery but now there is Jk on the scene.
This is the one I have, it is no longer available, but I bought two when I got my original one.
JBD 150 amp
this is the one I am thinking of buying a couple of and replacing what I am using now.
https://www.aliexpress.com/item/10050058........21CA%210%21AB&curPageLogUid=0mpGVzxqjBZP
The main reason is for the 2A active cell balancing feature over the passive balancing feature of my original BMS. Plus, the reviews on JK BMS have been amazing and the app is set up much nicer.
so, for those that have built their own batteries, would you go with an external 2-amp active balancer if you were building a new battery, or would you go with an active one built into the BMS
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