Battery question....

[Raptor Dave]

Originally Posted by GlasNav

So you want to install two separate banks of 6V batteries in series and then connect the two banks in parallel? WHY?

I was trying to find out if this would double my AH bank doing it this way?

[GlasNav]

Originally Posted by Raptor Dave

I was trying to find out if this would double my AH bank doing it this way?

Just realized you have a big arse toy hauler and need off grid power, disregard my questioning of the need.

If you have the funds, and can justify the expenditure, BattleBorn LiFePo and a large solar panel array is very effective. However, the Golf Cart 6V route is considerably cheaper although very heavy in regards to weight.

Yes, John's 4 battery drawing is correct, you just want to draw your voltage from opposite ends of the battery banks for equal draw / drain of all the batteries.

[Raptor Dave]

Originally Posted by GlasNav

Just realized you have a big arse toy hauler and need off grid power, disregard my questioning of the need.

If you have the funds, and can justify the expenditure, BattleBorn LiFePo and a large solar panel array is very effective. However, the Golf Cart 6V route is considerably cheaper although very heavy in regards to weight.

Yes, John's 4 battery drawing is correct, you just want to draw your voltage from opposite ends of the battery banks for equal draw / drain of all the batteries.

I examined the lifepo option. Long story short, this trailer was told/sold to me to have the 2 dragonfly bat in it. Come to find out the salesperson was reading off the card of "OPTIONS" and when we showed up to do the exchange with ours to theirs it only had 2 very small AH(55) ea batteries in it. Renegotiated and they left those batteries in it.
Nope..not doing lifepo. Too frigging expensive for my wallet and I'm not chasing some chinese brand for 300 a battery. I have enough stress in my life already.
These 2 6v should do the trick for what we are looking to do. Worst case scenario is possibly 2 more for a 4 pack.

But no one has answered my question about the AH's yet!
Does a 4 pack of 230AH 6v batteries properly connected DOUBLE my AH bank to 460? or does it all just stay at 230 and take longer to drain down?

[Stircrazy]

Originally Posted by Raptor Dave

Also, if I decide to go with 4 6v down the road. Are 2 6v volt cabled to make a 12v twice? doubling my amp hrs?

Thanks for any advice.

yes, you make two serial batteries then hook them in parallel, that's what I have been running in my trailer and now my 5th wheel for 16 years now.

Steve

[flybouy]

Originally Posted by wiredgeorge

If you take these answers to your wife, try and keep a straight face and act like you understand what you are saying and there is great benefit to whatever you tell her. Or just do like I do and say, honey, these are more better! I sometimes think the missus doesn't believe I am an expert on this type thing.

Originally Posted by Raptor Dave

I examined the lifepo option. Long story short, this trailer was told/sold to me to have the 2 dragonfly bat in it. Come to find out the salesperson was reading off the card of "OPTIONS" and when we showed up to do the exchange with ours to theirs it only had 2 very small AH(55) ea batteries in it. Renegotiated and they left those batteries in it.
Nope..not doing lifepo. Too frigging expensive for my wallet and I'm not chasing some chinese brand for 300 a battery. I have enough stress in my life already.
These 2 6v should do the trick for what we are looking to do. Worst case scenario is possibly 2 more for a 4 pack.

But no one has answered my question about the AH's yet!
Does a 4 pack of 230AH 6v batteries properly connected DOUBLE my AH bank to 460? or does it all just stay at 230 and take longer to drain down?

Yes, the 4 battery connected properly would result in 460 Ah capacity. Just an FYI, if the charging device remains the same then it will also take roughly twice as long to recharge.

[JRTJH]

Originally Posted by Raptor Dave

...

But no one has answered my question about the AH's yet!
Does a 4 pack of 230AH 6v batteries properly connected DOUBLE my AH bank to 460? or does it all just stay at 230 and take longer to drain down?

I am with you on the initial price of top drawer lithium battery power. And I completely agree with not wanting to chase a chinese business with problems after 90 days on the $300 version. So, for me, Sam's Club golf cart batteries are "just fine" for how I use them and I've no concerns with what to do on cloudy days.... My last set of Sam's Club golf cart batteries were going on their 8th season and still going great. Sam's had a sale for $79 per battery and I was planning to buy new ones at the end of the season, but at that price, I couldn't wait and pay almost 75% more 3 months later. But, 7+ years of camping on a set of batteries that cost $175 new and replaced for $190 after that much use was, for my thinking, a good decision not to risk those chinese knockoffs.

Now, as for your question about amp/hours and how to calculate them.

If the voltage remains the same, you add the amp/hours (parallel configuration) and if the voltage doubles, the amp/hours remains the same.

In short, if you put two 6 VDC 105 A/H batteries in parallel, the output is 6VDC at 210 A/H. And, if you put two 6 VDC 105 A/H batteries in series, the output is 12 VDC at 105 A/H.

So, your two battery setup is a series connection and your output is 12VDC at 105 A/H.

Now, for the 4 battery diagram above. Electrical power "follows the path of least resistance", so connected as shown, with the + and - cables on the same battery, the 12 volt path of least resistance is the top two batteries. In that wiring configuration, the lower two batteries will not be used for power draw until the resistance from depletion is greater than the resistance in the "not normally used" lower battery set. For that reason, I would recommend removing the - cable on the top right battery and connecting it to the - post on the lower right battery. That way, both "12 volt sets" are equally providing power and the entire 4 battery set becomes the "same resistance" so there's no "unbalanced power drain"..... Hope that makes sense to you.

[Raptor Dave]

Ok...thank you for telling me my assumption is correct.
Now a new curve ball....charging device!
What would I need to upgrade in that dept to have optimum charging?

Oh Thanks John...
you were typing and sending the same time I was!
Yes makes sense for little electrically mind.
Appreciate your time responding.

Ironically I was headed to batteries plus for a couple 6v 230ah @ 169 ea.
Got a text from batteries plus saying 15% off golf cart batteries.
Smiled all the way home.
Was looking at the agm same type duracell and $350 ea
walked out with 2 LSA for a little over 300.
My friend gave me a couple cores he had which was a 54 saving there.

[GlasNav]

I've always been a Newmar Power fan, but they are overkill for your application. I'm sure other members have more practical RV oriented devices in mind!

[JRTJH]

I believe your Raptor comes with an OEM WFCO 9875AD converter/charger ???

If it does, then that's the largest amp charger in the series. I'd think that it will do OK for most "sort of fast charging while boondocking"...

Why? Because most of your charging will be done during the day when your 12 volt system is not drawing away from the maximum charge current going to the batteries. If you were charging at night, then 12 volt lights, furnace, etc using part of that 75 amp potential charge current. During the day, probably no lights and minimal furnace in use, so 75 amps should be sufficient for a 2 battery recharge source. Now, when/if you add two more batteries, you may or may not find that it takes too long to recharge each day and want to look at a more powerful and faster charger.

But for now, with 2 batteries, charging every day for an hour or so "should" keep you fully charged going into the evenings.

[Raptor Dave]

Originally Posted by JRTJH

I believe your Raptor comes with an OEM WFCO 9875AD converter/charger ???

If it does, then that's the largest amp charger in the series. I'd think that it will do OK for most "sort of fast charging while boondocking"...

Why? Because most of your charging will be done during the day when your 12 volt system is not drawing away from the maximum charge current going to the batteries. If you were charging at night, then 12 volt lights, furnace, etc using part of that 75 amp potential charge current. During the day, probably no lights and minimal furnace in use, so 75 amps should be sufficient for a 2 battery recharge source. Now, when/if you add two more batteries, you may or may not find that it takes too long to recharge each day and want to look at a more powerful and faster charger.

But for now, with 2 batteries, charging every day for an hour or so "should" keep you fully charged going into the evenings.

Haha...I'm going thru all my pictures on my phone to find out which convertor/charger I have. You are correct with the 9875AD so I could look up the specs.
400 watt panels on the roof. (2-200)
My biggest concern since we got this trailer has been the draw from the 12V frig. added to all the ghost draw. We are generally pretty mindful in the evenings with lights and such. If it gets cold enough for a furnace to come on while boondocking I say put another sweater on!
Of course we have the on board gen also but want to keep that running at a bare minimum if possible.
We've never boondocked much in the past but with this set up plan on quite a few stops with no plugging in. Just trying get all my ducks in a row before the big 10K mile round trip this summer.

This monday we're headed out for a short 3 day boondock to test out these 2 batts and see how that works out.

[JRTJH]

We have two GC2 105A/H batteries in our Cougar. We boondock with no power other than a 2000 watt generator. We can last for 3 or 4 days with no furnace time using our gas refrigerator before we need to use the generator for a couple hours. I can't give you any idea on how your DC refrigerator will drain your batteries. I will say that that depends mostly on the temperature you're camping in. If it's hot, the refrigerator will use more power, if it's cool, you'll see less battery power used for the refrigerator.

I'd think that the only way you're going to get a feel for how well your rig will do (with all the variables involved) is just to go out and boondock with it and see what you use based on the way you camp. Have fun !!!!!

[Raptor Dave]

Originally Posted by JRTJH

We have two GC2 105A/H batteries in our Cougar. We boondock with no power other than a 2000 watt generator. We can last for 3 or 4 days with no furnace time using our gas refrigerator before we need to use the generator for a couple hours. I can't give you any idea on how your DC refrigerator will drain your batteries. I will say that that depends mostly on the temperature you're camping in. If it's hot, the refrigerator will use more power, if it's cool, you'll see less battery power used for the refrigerator.

I'd think that the only way you're going to get a feel for how well your rig will do (with all the variables involved) is just to go out and boondock with it and see what you use based on the way you camp. Have fun !!!!!

Thanks John
That's what we'll try and do.
Appreciate to responses.

[Stircrazy]

Originally Posted by Raptor Dave

Nope..not doing lifepo. Too frigging expensive for my wallet and I'm not chasing some chinese brand for 300 a battery. I have enough stress in my life already.
These 2 6v should do the trick for what we are looking to do. Worst case scenario is possibly 2 more for a 4 pack.

But no one has answered my question about the AH's yet!
Does a 4 pack of 230AH 6v batteries properly connected DOUBLE my AH bank to 460? or does it all just stay at 230 and take longer to drain down?

you realize all LFP batteries are Chinese, dragonfly's are just priced at 3 times what they are worth because they are a dealer only option

yes it takes you to 460, but it doesn't unless the Costco down there uses a different battery than our Costco. Costco new gc2 is 208AH out here, still good for the price. but what no one else is telling you that your 460 is really only 230 usable AH, when you start dipping over 50% usage on a flooded battery it starts to shorten the cycle life of the battery. lithium you can use 100% and get the rated cycle life and still use the battery beyond that as the cycle life on a lithium is defined as when the battery will hit 80% of its rated capacity, so unlike a lead acid which you throw out after 4-800 cycles (sooner if you use more of the capacity) as it won't hold a charge. A LFP (lithium iron phosphate) after 3500 cycles (average, new cells are up to 4500 cycles) will still be able to be used just with a reduced capacity. so my 304AH battery in my camper will only be a 243AH battery and those are usable AH. basically with LFP if you are over 50, you are buying the last batteries you'll ever buy. unless you do something that shortens their life which is actually quite hard as the BMS will protect it from cold charging and stuff like that. a lead acid is easy to kill in comparison.

[Raptor Dave]

Originally Posted by Stircrazy

you realize all LFP batteries are Chinese, dragonfly's are just priced at 3 times what they are worth because they are a dealer only option

yes it takes you to 460, but it doesn't unless the Costco down there uses a different battery than our Costco. Costco new gc2 is 208AH out here, still good for the price. but what no one else is telling you that your 460 is really only 230 usable AH, when you start dipping over 50% usage on a flooded battery it starts to shorten the cycle life of the battery. lithium you can use 100% and get the rated cycle life and still use the battery beyond that as the cycle life on a lithium is defined as when the battery will hit 80% of its rated capacity, so unlike a lead acid which you throw out after 4-800 cycles (sooner if you use more of the capacity) as it won't hold a charge. A LFP (lithium iron phosphate) after 3500 cycles (average, new cells are up to 4500 cycles) will still be able to be used just with a reduced capacity. so my 304AH battery in my camper will only be a 243AH battery and those are usable AH. basically with LFP if you are over 50, you are buying the last batteries you'll ever buy. unless you do something that shortens their life which is actually quite hard as the BMS will protect it from cold charging and stuff like that. a lead acid is easy to kill in comparison.

yep I fully understand the approx half AH usable on a lead acid.
I researched the LIpo and it's just not in my neighborhood for now. I say for now because I don't know how many AH we're going to use (need) for our lifestyle. I have invested $312 dollars for 2 230ah duracell for the time being to test all this stuff out.
Correct me if I'm wrong but I thought Battleborn was a US company making their own batteries?

Here was another deciding factor to stay with the lead cell. Every LIpo company I contacted and asked about using their lith batteries to start my gen they all said NO! So now I have to keep a deep cycle battery for that and run the rest of my rig off the lith. Too much confusion with wiring, charging and making sure I have all the right equipment on board to run all this efficiently. I go camping to relax and don't need any additional stress with all that.
I certainly appreciate your input and information tho.

[Stircrazy]

Originally Posted by Raptor Dave

yep I fully understand the approx half AH usable on a lead acid.
I researched the LIpo and it's just not in my neighborhood for now. I say for now because I don't know how many AH we're going to use (need) for our lifestyle. I have invested $312 dollars for 2 230ah duracell for the time being to test all this stuff out.
Correct me if I'm wrong but I thought Battleborn was a US company making their own batteries?

Here was another deciding factor to stay with the lead cell. Every LIpo company I contacted and asked about using their lith batteries to start my gen they all said NO! So now I have to keep a deep cycle battery for that and run the rest of my rig off the lith. Too much confusion with wiring, charging and making sure I have all the right equipment on board to run all this efficiently. I go camping to relax and don't need any additional stress with all that.
I certainly appreciate your input and information tho.

battle born is a US company assembling parts they buy from overseas to sell in the US and now world wide. personally I wouldn't use battle born or their parent company dragonfly energy, be cause their price is artificially inflated. LFP cells have dropped to 1/2 the price they were 1.5 years ago which is why we are seeing 300 buck 100AH batteries on amazon instead of 5-600 , I believe they are 1/4 the price or lower since when battle born first appeared on the scene. plus they are not the same design, they use the smaller cylindrical which is fine in its self but gives you a lot more connection points (solder joints) that can potentially fail over one made from prismatic cells.

as for stress, I find my LFP set up easier than when I had lead acid, wiring is identical as lead acid batteries if you are buying premade and charging is strait forward, just use the Li setting on your equipment. people like me with older setups might have to change the converter out.. in my case I had to change out the whole power centre as mine was a old glass tube fuse setup so I bought a li compatible one incase I decided to go that way.

as for the genny ya most premade one battery setup won't do it. nothing about the LFP chemistry but rather due to the BMS' output rating. most use a 100Amp BMS so you would need two batteries to give you the starting overhead. which would give you 200 usable AH. if you wanted to be extra safe you could put 4 batteries in parallel and have 400usable ah with 400amps output available. there are some companies that use 150a bms on a 100AH battery but not many. that's why I built my own, I have 150A bms on my 304Ah cells, but I understand building your own isn't for everyone even though its not really that much work.

[JRTJH]

Originally Posted by Stircrazy

...
as for the genny ya most premade one battery setup won't do it. nothing about the LFP chemistry but rather due to the BMS' output rating. most use a 100Amp BMS so you would need two batteries to give you the starting overhead. which would give you 200 usable AH. if you wanted to be extra safe you could put 4 batteries in parallel and have 400usable ah with 400amps output available. there are some companies that use 150a bms on a 100AH battery but not many. that's why I built my own, I have 150A bms on my 304Ah cells, but I understand building your own isn't for everyone even though its not really that much work.

The manual on the Onan 5500 (https://manuals.heartlandowners.org/...-HGJAB.pdf.pdf) recommends a battery with no less than 450 Cold Cranking Amps. While that spec is for 0F (-18C) starter motor operation, connecting two 100 amp BMS batteries would be an "iffy way to protect the battery BMS from what would appear as almost a direct short across the output terminals of the battery setup". If the BMS operates as is should, the starter motor wouldn't get any power and, heaven forbid, if the BMS failed or self destructed, the battery cells could reach a critical condition and start to self destruct. That's not what anyone wants to see in a remote campground where there's no emergency fire services and two 30 pound propane tanks sitting adjacent to the battery bank.... YMMV, but that's not "my kind of ideal solution to starting a generator.

Lithium power just isn't yet the "solution to all battery applications".

[Raptor Dave]

Originally Posted by Stircrazy

battle born is a US company assembling parts they buy from overseas to sell in the US and now world wide. personally I wouldn't use battle born or their parent company dragonfly energy, be cause their price is artificially inflated. LFP cells have dropped to 1/2 the price they were 1.5 years ago which is why we are seeing 300 buck 100AH batteries on amazon instead of 5-600 , I believe they are 1/4 the price or lower since when battle born first appeared on the scene. plus they are not the same design, they use the smaller cylindrical which is fine in its self but gives you a lot more connection points (solder joints) that can potentially fail over one made from prismatic cells.

as for stress, I find my LFP set up easier than when I had lead acid, wiring is identical as lead acid batteries if you are buying premade and charging is strait forward, just use the Li setting on your equipment. people like me with older setups might have to change the converter out.. in my case I had to change out the whole power centre as mine was a old glass tube fuse setup so I bought a li compatible one incase I decided to go that way.

as for the genny ya most premade one battery setup won't do it. nothing about the LFP chemistry but rather due to the BMS' output rating. most use a 100Amp BMS so you would need two batteries to give you the starting overhead. which would give you 200 usable AH. if you wanted to be extra safe you could put 4 batteries in parallel and have 400usable ah with 400amps output available. there are some companies that use 150a bms on a 100AH battery but not many. that's why I built my own, I have 150A bms on my 304Ah cells, but I understand building your own isn't for everyone even though its not really that much work.

Appreciate your input....yes, building a LIpo system to meet my needs is not what I would consider a fun project. After everything I've read and all the input I've received from Lipo companies and others voicing their concerns and positive side to it, I've decided to invest $312 dollars for 2 6v and gamble that I have enough bank to get thru the night and enough left over if I need to start the gen in the morning. If that don't work, 2 more 6v will probably be in order.

[Stircrazy]

Originally Posted by JRTJH

The manual on the Onan 5500 (https://manuals.heartlandowners.org/...-HGJAB.pdf.pdf) recommends a battery with no less than 450 Cold Cranking Amps. While that spec is for 0F (-18C) starter motor operation, connecting two 100 amp BMS batteries would be an "iffy way to protect the battery BMS from what would appear as almost a direct short across the output terminals of the battery setup". If the BMS operates as is should, the starter motor wouldn't get any power and, heaven forbid, if the BMS failed or self destructed, the battery cells could reach a critical condition and start to self destruct. That's not what anyone wants to see in a remote campground where there's no emergency fire services and two 30 pound propane tanks sitting adjacent to the battery bank.... YMMV, but that's not "my kind of ideal solution to starting a generator.

Lithium power just isn't yet the "solution to all battery applications".

ya there are lots of better "premade" batteries out there that have 150 amp even 200amp bms in them now with momentary capability of double that. there are some single ones that will start a genny with just one. the trick is knowing how many cranking amps you need and getting the right amount of batteries to give it to you, don't blame the battery if you don't set it up properly. and it wouldn't be anywhere near a direct short across the batteries as a LFP has the capability to put out much more amperage than a normal battery due to the lower internal resistance and the higher storage capability, but the limiting factor is the BMS that is used, cheep batteries get cheep BMS, but your not going to kill the bms it will just disconnect the battery if the amperage gets to high, and reconect it when the demand lowers. that's what it is designed to do, it doesnt self destruct to protect the battery. you can get a 400amp bms but I think they are over kill but they are out there for a 12V battery. generally the higher in capacity, voltage and quality you go the larger the BMS goes. 150AH is starting to be common on 100AH 12v batteries where when you get up into the 300ah batteries 250A is quite common

[Stircrazy]

Originally Posted by Raptor Dave

Appreciate your input....yes, building a LIpo system to meet my needs is not what I would consider a fun project. After everything I've read and all the input I've received from Lipo companies and others voicing their concerns and positive side to it, I've decided to invest $312 dollars for 2 6v and gamble that I have enough bank to get thru the night and enough left over if I need to start the gen in the morning. If that don't work, 2 more 6v will probably be in order.

yup, that's what I did for years, four 6V served me well I only initially went to LFP for the reduced size, weight and maintenance while increasing storage so I could run more stuff while camping. if I had a generator who knows, I personally don't like generators and they are being restricted so bad in parks up here they almost are getting pushed out, so I went solar and battery storage as 2 to 3 hours of genny time a day wouldnt keep up.

[JRTJH]

Originally Posted by Stircrazy

... cheep batteries get cheep BMS, but your not going to kill the bms it will just disconnect the battery if the amperage gets to high, and reconect it when the demand lowers. that's what it is designed to do, it doesnt self destruct to protect the battery. you can get a 400amp bms but I think they are over kill but they are out there for a 12V battery. generally the higher in capacity, voltage and quality you go the larger the BMS goes. 150AH is starting to be common on 100AH 12v batteries where when you get up into the 300ah batteries 250A is quite common

The RED: Cheap batteries get cheap (potentially problem prone) BMS. Out in the middle of the desert or 15 miles from the closest cell phone tower is not the place to rely on a "cheap battery with its cheap BMS"

Yes, there are "higher capacity BMS in more expensive 12 volt lithium batteries" but, then we're back to comparing "apples @ $300" to "oranges @ substantially double or triple dollars"... So, the initial cost comparison of "You can buy quality batteries for $300 these days" goes out the window, when the least expensive lithium battery with a 400 amp BMS starts in the $1000 range.

As I said in a previous post, lithium works for some applications, but the technology has not yet "matured" to provide the alternative for all applications at an affordable price. Sure, most applications can be "met with a lithium alternative" but the question for most consumers is similar to the two questions of buying an EV. Does the current price offer a reasonable alternative? AND does that alternative purchase meet all the needs expected for the investment cost?

For many RV applications, lithium just doesn't yet offer an AFFORDABLE alternative that produces the same "FLA performance" in high amperage requirements at a cost point that is comparable to FLA pricing.

I'll agree with you, 'There's a way to make it work if you try hard enough with some out of the norm and/or hard to find and more expensive lithium products, but then we're back to "but it ain't an off the shelf purchase of a single product with the ease of a "connect and go camping" solution.