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12V LiFePo4 batteries, choices, education 2date


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#11 Stokeme

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Posted 24 March 2018 - 09:26 PM

I’ve carried on with lithium batteries in two threads, hijacking one (see below), and creating this one. Consider following both threads. When I finally get my Grandby Shell mid April, I will start my own build thread and have everthing in one place.
http://www.wanderthe...project-photos/

I will post the StarkPower coupon code ... Coupontwobattery ... here now, which is 5% off batteries. I hesitated on my first post because I have no experience with lithium or Stark, no past history to provide a review, no testimonial to offer. My own personal journey is beginning. I chose lithium mostly for weight, # of life cycles offered, % of battery depletion offered, perceived long term value. There are additional cost factors involved though, which bear consideration.
One is a lithium specific charger. Some reasons given in post above ... you can extrapolate listed charger amperage to hours needed to restore Ah depletion, but until you specifically trial anything it is a guesstimation. Lithium requires ultimately 14.4v to be completely charged. Too much amperage, not controlled & moderated properly, from a charger, will fry your expensive battery. Take care, don’t go cheap, with charger unless you are very sure of results.
Two is you need specialized control & moderation, between your engine to house connection, for recharging during driving. There are different chemistry’s involved, lead acid & lithium. Your alternator most likely will fry your lithium battery if not moderated. To add additional complexity to this marriage, when your engine to house conjoined batteries are at rest, your house is at a higher resting voltage compared to your engine. Your engine will actually drain your house battery until they equalize in voltage, reducing valuable Ah in your house battery. If you want to pursue engine to house recharging you may need this below ... Yeow! $
http://www.sterling-...erycharger.aspx

I can not offer tech speak to anyone. I am not qualified. This is what I have learned so far, gathering info, some after the fact. I invite correction by anyone, I want to get it right myself. I am a learning novice. My goal is a healthy lithium system. Buyer beware, do the research, protect your investment.
I will try to live without the Sterling unit above and will initially abandon my engine to house connection altogether. I will try to recharge by solar when driving. We will see how successful that is in the real world. Starting out with 2x120w flex panels on roof = 240w and one additional portable 100w folding flex panel when I am at camp. If possible logistically I will add another 120w to my roof after getting my camper.

Edited by Stokeme, 25 March 2018 - 02:05 AM.

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#12 Vic Harder

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Posted 25 March 2018 - 02:23 AM

I am loving what I am reading about this Stirling B2B unit

 

http://www.sterling-...sEng_GerV56.pdf

 

To keep the ultra geeks happy (we know who we are on this forum  :) ) you could use TWO of these... one from the alternator feeding your truck battery, and another feeding the camper batteries.  $$$, but wow.... no more issues with having to get custom alternators or custom marine grade regulators.


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#13 Stokeme

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Posted 25 March 2018 - 04:31 AM

Vic ... why would u need a B2B unit from the alternator feeding your truck battery? Please explain. Thanks.
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#14 ckent323

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Posted 25 March 2018 - 11:54 AM

Also 60 amp limit so you cannot use it to jump the starter battery from the house battery although you could charge up the house battery.

 

(That is what the Sterling Power rep old me via email).

 

and these things are pricey, around $400 for the 60 amp model which I think is needed.

 

Regards,

Craig


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#15 Stokeme

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Posted 25 March 2018 - 03:33 PM

Hey Craig, with a house lithium bank, I will not consider jumping my engine. With a 30amp B2B limit I should theoretically be able to charge my 100Ah battery, 80% depleted, in ~3 hours of driving. If I add another 50Ah Battery (to use in my custom fishing canoe & multitask as added house storage), the combined bank should charge in ~4 hours driving, assuming 120Ah depletion. Real life usage may vary.
I will carry a separate jump starter for my engine battery. I want to keep my lithium limited to storage only, no attempted cranking usage.

Edited by Stokeme, 25 March 2018 - 03:51 PM.

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#16 ckent323

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Posted 25 March 2018 - 05:55 PM

Mark,

 

Does the Sterling (ProMariner) B2B have a relay that latches and prevents charging when the current need is more than 30 A?   

 

That is the problem I found with the Balmar Duo Charge otherwise the Balmer would have been my go to solution.

 

Craig


Edited by ckent323, 25 March 2018 - 05:55 PM.

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1993 Dodge Cummins W-250 Club Cab long bed, 2007 FWC Keystone


#17 Vic Harder

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Posted 26 March 2018 - 05:45 AM

Vic ... why would u need a B2B unit from the alternator feeding your truck battery? Please explain. Thanks.

Oh, just to keep us geeks happy... for example, my 2002 GMC alternator and regulator assume I have a FLA battery.  I don't.  So, the charging parameters are not ideal.  If I wanted optimal charging for my truck's starting battery, I could futz with this and install something like the Sterling to optimize that.  Or, just live with it and buy a new battery every 4-5 years.  I prefer this latter, lazy approach.   :huh:


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#18 Vic Harder

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Posted 26 March 2018 - 05:47 AM

Mark,

 

Does the Sterling (ProMariner) B2B have a relay that latches and prevents charging when the current need is more than 30 A?   

 

That is the problem I found with the Balmar Duo Charge otherwise the Balmer would have been my go to solution.

 

Craig

Craig, from my first reading of the manual, the answer is yes.  the 30A unit limits current through the unit to 30A.  The video specifically mentions this as a feature that will avoid frying the DC circuitry in your "Caravan" if you plug in a super high load in your kitchen and the draw from the house and starting battery is too high.


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#19 ckent323

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Posted 26 March 2018 - 09:47 AM

Vic,

 

If that is true then it seems that would be a problem if one were trying to use it for recharging a house battery bank.  I think it is not uncommon for the charge differential to be more than 40 or even 50 amps between the vehicle and house a battery bank in many campers, unless perhaps if one runs the vehicle engine everyday.

 

One option might be to go to the larger 60 amp unit (1260).

 

Thinking about this, perhaps it only limits the current to no more than 30 amps but will still allow charging with a large current differential.  That would not be such a big deal I think.

 

That would be different than what the Balmer rep told me about the Duo Charge unit -

"We do have a device called a Digital Duo Charge (DDC). It goes between two battery banks and can drop the voltage to the secondary battery but it cannot increase it. So if the main bank is charging at 14.6 volts and the secondary want to be at 14.3 the DDC can reduce it down. The DDC has a 30 amp limitation. If the secondary bank's demand is over 30 amps the DDC shuts down, waits a few seconds and tries again. If the demand stays over 30 amps the DDC won't turn on. I think the 30 amps limit is going to be a show stopper. Your "house" AGMs will be discharged more deeply than the FLA start battery and require more than 30 amps to recharge them. I would like to make the sale but I don't want you to buy something that's not going to work for you."

 

 

Craig


Edited by ckent323, 26 March 2018 - 09:53 AM.

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#20 Vic Harder

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Posted 26 March 2018 - 09:25 PM

Craig, the Stirling does sound very different than the Balmar unit.  It can change the input voltage up and down, and it specifically states that it can take large input currents and limit the output to protect the circuitry and the target batteries.

 

But I could be wrong.  I'd love it if you also read the manual and watched the videos and gave us all your opinion on these interesting sounding units.


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