Adding 2 additional different brand LifeP04 100ah batteries to my NEW solar setup in my RV.

[BamBam424]

I just upgraded from 4 Trojan Lead Acids to 2 LifeBlue 100ah lithiums with bms and 400 wt solar panels. 2 months now and I want to add 2 more 100ah batteries. LifeBlue at $800+ each. On Amazon are many 100ah brands for under $400 each with the same 100ah specs. Why would I buy 2 more LifeBlue's? I would plan to charge the new ones and LifeBlues to 100% individually first and then add the 2 new ones in parallel to my LifeBlues.

1. Will read the LifeBlues 10 yr warrantee first on mixing brands
2. Any reason to not do this? Saving $400 is nice.

Thanks Bruce

 

[sunshine_eggo]

Why are you adding batteries?

 

[BamBam424]

Why are you adding batteries?

Class A needs more hours of battery life. I almost have this down as is to not need to use my generator at all, but need to run it in the eve to top off the batteries to run inverter all night for my CPAP. 2 more will be nice too when I move north where there is less sun. Comfort of power

 

[MrNatural22]

Class A needs more hours of battery life. I almost have this down as is to not need to use my generator at all, but need to run it in the eve to top off the batteries to run inverter all night for my CPAP. 2 more will be nice too when I move north where there is less sun. Comfort of power

Check the specs on your Cpap machine. Most run on 12v (respronics) or 24v (Resmed) No need for inverter or the excessive draw they use. Adapters are easily available. My Respronics Bipap will run 5 straight nights on a 40ah 12v LiFePo battery. If Resmed a 12-24 volt buck converter would work.

 

[BamBam424]

Thanks. I was trying to make this a simple question. I want more longevity in my current system by adding 2 more batteries. Do all 4 HAVE to be the same brand and identical? I looked to buy these as they seem to be very close to my LifeBlue.
https://www.amazon.com/LiFePO4-Lith...coding=UTF8&psc=1&refRID=VYQMND3JPMKHHSN44583

 

[sunshine_eggo]

Class A needs more hours of battery life. I almost have this down as is to not need to use my generator at all, but need to run it in the eve to top off the batteries to run inverter all night for my CPAP. 2 more will be nice too when I move north where there is less sun. Comfort of power

I asked the question for a reason. Two more batteries are only going to delay the inevitable. If you are using more than your solar can deliver in a day, you will always go back to the generator.

Both of the above two bolded portions are fixed by more solar, not more batteries.

Solar determines how much energy you can use in a day.
Batteries determine how long you can go between charges.

Thanks. I was trying to make this a simple question.

Unfortunately, you think you're asking the right question, but I don't think you are based on your responses/stated goals.

I want more longevity in my current system by adding 2 more batteries. Do all 4 HAVE to be the same brand and identical? I looked to buy these as they seem to be very close to my LifeBlue.
https://www.amazon.com/LiFePO4-Lith...coding=UTF8&psc=1&refRID=VYQMND3JPMKHHSN44583

Sure, you can add more batteries of different brands, but it's going to just mean you can run your generator twice as long, half as often, i.e., if you're running it 30 minutes every day, doubling your batteries will allow you to run the generator 1 hour every two days - same run time.

You need to match your production with your consumption.

If your goal is to get away from using your generator, you need more solar, not more batteries.

Something @MrNatural22 may have alluded to is 12/24V power off an inverter is horribly inefficient. Depending on your inverter, it may be gobbling a huge portion of your battery capacity just by being on and with no loads. Additionally, the DC-AC-DC efficiency is only about 70-75%. If you're only running the inverter to power the CPAP, you will likely cut your power consumption dramatically by feeding off DC direct and shutting down the inverter at night.

You really should investigate the DIY Checklist in my signature... Step #1 on that list is incredibly important. If that is skipped, vast sums of money are wasted, OR the system is grossly under-designed. I suspect you've skipped Step #1.

 

[12VoltInstalls]

Hi jack
I’ve got someone asking me about a 24V cpap and dataplate says 3.75A while his booklet says it needs a 58Ah.

likely cut your power consumption dramatically by feeding off DC direct

Respronics Bipap will run 5 straight nights on a 40ah 12v LiFePo battery. If Resmed a 12-24 volt buck converter would work

So the resmed uses way more power?

Anyways:
Is there a decent 50Ah 24V LiFePo battery?

Per Ah this seems about twice the money it should be considering the price of zooms 100Ah 12V.
He’s merely needing one overnight and portability which is why I was looking 50Ah due to weight. 3.75A is like 30Ah not 58

Please tell me what I’m missing?
Thanks ?

 

[MrNatural22]

Not written in stone but, The output on the power supply are what the supply is capable of producing not what the cpap is using.
My 12v unit can run several nights on a 40 ah battery. Not real sure how to calculate the resmeds power usage but I suspect it could be powered thru a 12-24v buck converter for more than one night easily.

Maybe someone more knowledgeable could chime in on how to correctly figure the Resmeds requirements???

 

[12VoltInstalls]

Maybe someone more knowledgeable could chime in on how to correctly figure the Resmeds requirements???

That would be great. My BIL is almost 3hrs or I’d drive over there and figure it out by myself.

Not real sure how to calculate the resmeds power usage but I suspect it could be powered thru a 12-24v buck converter for more than one night easily.

I’d like to avoid buck converter or transformer and do prefer to use a single 24V battery or a pair of small 12V for transport ease.

Resmed documentation says 4.59A running with a 56Ah battery requirement. No mention of battery voltage…
I’m assuming that’s a 12V battery

 

[sunshine_eggo]

IIRC, my 24V ResMed S9 uses about 0.25kWh/day (6-7 hours use, plugged in and pulling 1-2W standby rest of the time) with full heat/humidity with the AC adapter.

Peak is about 70W but that's only when the heater is on. It cycles that on and off. It's more typically around 20W.

 

[12VoltInstalls]

IIRC, my 24V ResMed S9 uses about 0.25kWh/day (6-7 hours use, plugged in and pulling 1-2W standby rest of the time) with full heat/humidity with the AC adapter.

Peak is about 70W but that's only when the heater is on. It cycles that on and off. It's more typically around 20W.

You are awesome. That’s the important info I needed.

/hijack

 

[APetersen10]

I also had the same dilemma, I originally purchased two LifeBlue 200AH batteries, and placed them in parallel @ $2,000 each. Then I decided that I needed to add two additional 200AH Chins Batteries at 1/2 the price, in parallel, but the Chins engineers said that configuration would not work, because of the different BMS's of each brand. Therefore, I placed each pair of batteries on their own separate banks, each with individual battery monitors. I use one to exhaustion, then I switch banks, and use the second pair of Chins batteries to exhaustion. Unfortunately, I have to also charge each bank separately. However, after all said and done, I can say that the Lifeblue batteries are great, because of the smart blue tooth BMS. I love the ability to just look at my phone to get an accurate condition of the batteries. However, the Chins batteries did not come with blue tooth BMS, and therefore, I have to rely on my shunt display to get the condition of my Chins batteries. I have found that the shunt display is not always accurate, but by the most part, each pair of batteries seem to be holding their own and discharging at the same rate when I use my electric fire place, or air conditioner. If you like the convenience of the Phone app on the Lifeblue batteries, and can afford them, I would stick to one brand. I often regret purchasing the Chins batteries, simply because of the lack of Blue tooth for my phone App. If money is an issue, then working with several different banks is an option.

 

[sunshine_eggo]

Chins lied to you.

 

[BamBam424]

So far no problems with different sets wired in together. Did like YouTubes like and video on the Weiss brand when he cut them open.

 

[Timaz]

Sorry everyone got off on different tangents and just didn't answer your simple question. Some people just can't do that.

 

[sunshine_eggo]

Sorry everyone got off on different tangents and just didn't answer your simple question. Some people just can't do that.

Answered in #6.

In many cases, people ask the wrong questions because they're inexperienced, so sometimes, as volunteers trying to actually help, we try to dig a little deeper. One of the most common mistakes people make is, "My battery is running out. I need more batteries." More often than not, that's not the solution.

What did your post contribute?

 

[BamBam424]

Timaz, should have read the 100 lady replies to a dating question I had posted on a dating site. 90% diagnosed the question with questions of the question 10 answered it was amusing to read them as they came in.

 

[upgrader]

I’m an incrementalist. Upgraded to a larger travel trailer 2 years ago. I immediately prepared it for boon docking: dropped a Battleborn 100ah along with several 12v outlets (1 for my CPAP). Last year, I installed a rooftop solar system - three 100w panels (no additional rooftop space for a fourth panel); 40v MPPT controller, etc.

I’ve been boon docking in my previous trailer, sans solar, for over 12 years, and I had absolutely no problems with this setup. It powered my lights, CPAP, 12 volt stereo, mobile devices, and ceiling fan from dark to dawn. Bye bye generator. The I’m a happy solar camper.

Ever the incrementalist, I would like to complete my system by adding a 1500 or 2200w inverter. But that will require an additional lithium battery. A 100ah SOK battery would save me at least $200 over a new Battleborn.

My question: can I mixed the two brands? @sunshine_eggo: how best can I go about verifying #13.

 

[12VoltInstalls]

would like to complete my system by adding a 1500 or 2200w inverter. But that will require an additional lithium battery

Not arguing but why do you need a 1500W or 2200W inverter? In other words, what watt requirement does this serve?

At 2000W+ you are getting to some big cables for 12V batteries. If you won’t be running a microwave or a cooker-pot (which makes little sense to me at 200Ah of storage) a 1200W or even 1000W will run an electric fridge 24/7 as well as a number of other things like coffeemaker or vacuum. (I’ve done and am doing this myself).

For that 600- 800W of panels and probably 300Ah of batteries is a better match if you wish to consume at that level. Gives you headroom for clouds and you won’t have to think as hard about what to run (tv?) in the evening as sun power wanes.

Why “so many” panels? Because anticipating flat-mounted panels your harvest potential is reduced on one hand and day-time use of power will be not a worry or concern for things like pre-heating of water by solar when batteries are 90%+. And 300Ah gives you cloudy-day autonomy benefits without worry.

With lithium 300Ah feels like a luxurious amount of power for a small solar power system.

 

[upgrader]

Thanks 12VoltInstalls. You’re reading my mind re inverters which can best meet my needs.

The solar setup I have will not expand: no more rooftop space for panels; No need for larger solar controller.

I have two problems:

• What size inverter? 1200V vs 1500-2200V
• Physical constraints

If I add a 1200W pure sine inverter, I could get by with my current 100ah lithium. Any larger inverter will require an additional lithium battery.

Our current compliment of AC powered goodies can be powered with a 1200V inverter. Inside the trailer, I have a 24v TV, 700W microwave, notebook computers, blow dryer, power tools.

However, I can imagine us adding additional appliances. For instance, it’s possible we may wish to use a coffee maker or toaster in the future. It would be good to know that our propane/electric refrigerator/freezer could be powered via a larger inverter in an emergency.

So, my bottom line: I don’t want to revisit our setup which could happen if if we decide to add goodies. A 1500W - 2200W inverter will cover any unforeseen needs in the future. Want to do this once, and not revisit inverter size.

My other problem surrounds the physical size of the inverter. My solar basement is 20” x 21”. Pure sine Inverters require 6-12” of space around the inverter to prevent objects from blocking the vents and to provide enough air to circulate. Most 1500V & 2000V inverters are 16-18 inches long.

I briefly considered Rich Solar/Renogy 2000V inverter, only 12” long. But it has very mixed reviews.