EFB camper batteries -- has anyone used them?

[Dewclaw]

I am considering spending the extra cash to buy Interstate EFB batteries ($200 each) for the Northern Lite.  I don't want to change the charging system to accommodate AGM or Lithium batteries. The two Group 24 just fit in the NL battery compartment so I can't go to a larger group size.  I can dry camp four days (or less) with the flooded batteries so am hoping that I could stay out longer with EFB batteries.  I would like to hear from anyone who has used EFB batteries. 

This is my first post on this new forum, though I was a regular on the old rv.net forum.  I tried the camper forums on Facebook but they don't have the level of expertise that was available on rv.net.  When I asked the EFB question on the Facebook groups all I got were replies saying go AVG or Lithium or a larger group size. 

I do hope that this new forum format will work as well as the old rv.net forums did. 

[nickthehunter · Accepted solution]

From what I understand, you don’t get more run time (amp-hours) from EFB’s, you get more cycles, I.e. - they last longer (more years) before they go kaput.

[Dewclaw]

Lots of good info posted on this forum, as usual.  Thanks for the replies and discussion.  So, to wind it all up, I just bought two more Costco Interstate Deep Cycle, the same as I've been using for the past 3 years.  Total for both batteries was $160.  I have them installed and ready to go. 

I did notice that they have become a lot heavier than the last time I replaced them.  🙂

[StirCrazy]

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@Dewclaw wrote:

I did notice that they have become a lot heavier than the last time I replaced them.  🙂

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ya isn't that weird how that happens haha, that was part of the reason I went to LFP 48lbs for one 300AH battery instead of 78Lbs for one GC battery that would give me 100ah to use at 6V and only have a 1/4" of room to spare gettng into the battery compartment 😀

[valhalla360]

Most newer chargers can do lithium but given the age, your's might not. The chargers aren't that expensive. I just replaced one for $130 last fall (installed it myself as it's not too difficult).

I would go with 6v golf cart batteries as they are true deep cycle. Hard to find true deep cycle in a 12v battery (most of the marine/combo are just relabeled starting batteries with a higher price).

Not a fan of AGM for an RV. They are designed for use in planes and boats where they eliminate the risk of the fluid leaking out if you tilt and roll. If your RV is tilting enough to matter, you have bigger problems. If you don't want to top up the fluid, just get a sealed battery...same difference, if you boil off the water both AGM and sealed are toast as you can' t replace the lost water. 

[MORSNOW]

I also went from stock flooded batteries to AGM Lifeline batteries as to avoid dealing with checking and adding water and changing out the factory charger.  An AGM is basically the same as flooded, it's just that the acid is absorbed in a matting and no need to ever add water.  I don't boondock for weeks on end so changing to lithium and its associated cost never appealed to me.  EFB batteries are not true deep cycle, they are combo starting batteries and are worse than an ordinary flooded deep cycle battery.   

[StirCrazy]

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@MORSNOW wrote:

 I don't boondock for weeks on end so changing to lithium and its associated cost never appealed to me.     

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I don't buy that cost factor anymore,especial for people who buy AGM.  a trojan T-105 costs almost 300 bucks in canada after taxes depending where you live, two of thoes will give you 100-115ish usable AH with out reducing cycle life.  so 6 of them will cost you 1800 bucks, where as on amazon canada you can get a redoo 300AH 12V battery for 1000 bucks, or 3 100amp for about 1100 and if you include 200 bucks to change out the converter your still 500 to 600 bucks cheeper and we haven't even talked about cycle life.  even if we nock the number of 6V batteries down to 4 (which you need to run a microwave deicently with out getting low voltage out of your inverer) you can get two 100Amp LFP for about 800 now so 1000 bucks compared to 1200 for t-105's.  now if we talk AGM then the price goes up even more, for a quality deep cycle agm your looking 4 to 500 bucks up here.  

But as I said in my first reply, if what you have works and you just want to stay cheep, them go to costco and replace what you have.  if you looking to reduce weight and size, while increasing usable capacity, then start looking at LiFePO4..  That is what got me looking, I was using two 6V deep cycles and losingan outside storage compartment.  so that weights about 140lbs and gave me about 100ah, now I have 300 AH for 48lbs 

[MORSNOW]

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@StirCrazy wrote:

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@MORSNOW wrote:

 I don't boondock for weeks on end so changing to lithium and its associated cost never appealed to me.     

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I don't buy that cost factor anymore,especial for people who buy AGM.  a trojan T-105 costs almost 300 bucks in canada after taxes depending where you live, two of thoes will give you 100-115ish usable AH with out reducing cycle life.  so 6 of them will cost you 1800 bucks, where as on amazon canada you can get a redoo 300AH 12V battery for 1000 bucks, or 3 100amp for about 1100 and if you include 200 bucks to change out the converter your still 500 to 600 bucks cheeper and we haven't even talked about cycle life.  even if we nock the number of 6V batteries down to 4 (which you need to run a microwave deicently with out getting low voltage out of your inverer) you can get two 100Amp LFP for about 800 now so 1000 bucks compared to 1200 for t-105's.  now if we talk AGM then the price goes up even more, for a quality deep cycle agm your looking 4 to 500 bucks up here.  

But as I said in my first reply, if what you have works and you just want to stay cheep, them go to costco and replace what you have.  if you looking to reduce weight and size, while increasing usable capacity, then start looking at LiFePO4..  That is what got me looking, I was using two 6V deep cycles and losingan outside storage compartment.  so that weights about 140lbs and gave me about 100ah, now I have 300 AH for 48lbs 

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Valid points, I didn't realize lithium costs have come down so much.

[StirCrazy]

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@MORSNOW wrote:

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Valid points, I didn't realize lithium costs have come down so much.

ya its been crazy the last year.  I am building my second battery and it is bigger than the first I built  (304AH Vs 280), but 200 bucks cheeper.  now I see the price of my cells has dropped to 125US each so for 500.00 US, plus a BMS (80 US) you can buld a 304AH battery that is 8" x 7.5" x 11.5" (aprox) and 48ish LBS

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[deltabravo]

I can't see any reference to the EFB batteries being "deep cycle"
They look like starting batteries, design for vehicles with "auto start / stop"

I changed to AGM batteries and didn't need to change anything on my charging system when I did the upgrade.

https://www.youtube.com/watch?v=bb1Uk2j70Ts

[Grit_dog]

Basically battery choices are endless now. 
Pick the most useable ah/$ or whatever combo of ah and $ you want to spend. 
And AGM will charge just fine off of virtually any quality converter. And if it’s a cheapo converter like a wfco then it’s not great in any battery scenario. 

[Dewclaw]

Thanks to both of you for the insight.  I suppose that I will just continue to use ordinary flooded deep cycle batteries and take the Honda generator along if we want to stay out longer.  It's been working for all of my campers since 1992.  I just wanted something new and improved without any hassle.  🙂

[StirCrazy]

ya if you don't want to do any other changes and can fit them 200AH 6V batteries are your best bet.  I went to LiFePo4 becaue I wanted to triple my capacity and cut the weight down from about 160lbs to 48lbs and gain an outside storage compartment back.   but my solar and my converter were Li compatable already so it was just a case of moving the power wires from the outside storage to the inside closet which is right beside each other.  

[StirCrazy · Accepted solution]

my buddy has them in his camper, they work but he still only has 180ah between the two so in reality about 90 usable AH.  he is looking to change to LiFePO4 now though to get more AH in the same amount of space.  

EFB are flooded batteries , just have some reenforcing and such, to make them a little stronger and resistant to vibration and they claim more cycle life but don't list anything for it.  also what makes me sceptical about them is that they list CCA of 800 amps which means it leans towards more of a hybred deepcycle/starting battery rather than true deep cycle.  they do show that it should get 400 cycles if you stay to a 80% depth of discharge so if you want that you would have to keep your usage down to 72AH/battery (assuming a group 27 with 90AH capacity) or you start to ahorten that life.  if you stay at around 50% like I said above (45ah/battery) then you would probabaly get a longer life out of them.  

I know you said you didn't want LiFePO45 as you would have to change the converter section, did you look into what that would cost.  it really isnt much to buy an external charge and get some one to install it for you if you are not comfterable with it.  then if you buy premade batteries you could get two that would fit and give you over twice the usable power you have now probably outlad your camper, but thats just a thought, the other is to measure a 6V battery at costco and see if they will fit.  thats cheeper than what your looking at and will give you a little more power but way more cycle life 

[nickthehunter · Accepted solution]

From what I understand, you don’t get more run time (amp-hours) from EFB’s, you get more cycles, I.e. - they last longer (more years) before they go kaput.