LiFePo4 - what components required?

[Wo_ody]

Premise: certainly solar is fine but most of my camping is in the shade or in low solar areas so no solar. And there are more no solar reasons too.

Intent is to have a battery bank of 4S-8P CALB LiFEPO4 batteries. Using 100 amp cells would give me +/- 600 amps of usable 12V nominal power. When available, a 110 AC land line would be used to power the Truck Camper as well as charge the batteries. When not AC connected, the batteries would be charged by 2nd engine alternator (+/-200 amp) dedicated only to battery charging. And a third option would be to charge the batteries using something like a Honda EU2000i portable generator plugged into the AC.

LiFEPO4 require a battery balancing system which most "normal" inverter/chargers do not provide. Not being "Edison minded" I'm trying to wrap my head around the electrical components necessary to make this work as well as the 2D architecture or flow chart of the AC power circuit and the intergration of the alternator power circuit. Simply put, what goes where?

Also, if you are experienced with LiFEPO4, please recommend specific products or vendors where items could be purchased or a design/install house who could provide such a system.

Thanks for your response.

[mkirsch]

Look to the radio control aircraft world for charging information on these batteries.

We have been successfully and safely charging the Lithium Polymer batteries for a decade. Early on things were a bit hairy and there were some fires but the industry made some tweaks to the chemistry and we collectively came up with a technique of "balance charging" by monitoring each indivudal cell voltage.

Most modern aircraft chargers support LiFePo4 technology and operate off 12V.

[mchero]

OK, I currently have 4 Golf cart batteries. Cost me $320.00 that's giving me 464 Amp Hours.

I can swap them out with two of http://www.lithiumion-batteries.com/products/12v-300ah-lithium-ion-battery/ then I'll have 600AH for just 7,000.00

[NinerBikes]

Salvo wrote:
Have you looked at SmartBattery SB50?

They have all the current sharing electronics already installed.

http://www.lithiumion-batteries.com/products/12-volt-lithium-ion-batteries/12v-50ah-lithium-ion-batt...

You need to add extra electronics with the batteries you listed. Have you seen this?

http://www.electriccarpartscompany.com/1-60-Batteries-Per-BMU-br-EV-Battery-Management-System-BMS-br...

Hopefully I am still young enough to go RV'ing when those become Surplus Telecom batteries for sale.

[mchero]

Id like to see some CURRENT pricing on a setup.

[mchero]

Id like to see some CURRENT pricing on a setup. Yeah, lots of chatter about everything but cost.

[pianotuna]

Hi Phil,

The stark power are rated to be usable down to -30 C (-22 f). That's NEARLY good enough for me. Now if I did not have a beer budget.

[pnichols]

The first link that Salvo listed above shows some excellent Lithium RV batteries in standard automotive physical sizes with all charging control built right into the case so that standard RV chargers can be used.

Here's another link for Lithium RV batteries in standard automotive physical sizes with all charging control built in:

http://www.starkpower.com/spnews/energystoragebatt/

[Gdetrailer]

rexlion wrote:
For those who are wondering, LiFePO4 is Lithium Iron Phosphate chemistry. Considerably safer than the "lithium ion" (a generic term, in this instance probably Lithium Cobalt Oxide) batteries we hear about in the news lately, burning up the hoverboards.

But my only experience is with the 3V LiFePO4 cells I use in one of my flashlights. Each cell is charged in its own charger bay. No help for what the OP is doing.

While LiFePO4 batteries "may" consider "safer" they still demand the utmost respect when it comes to charging/discharging current/voltage..

They are still basically fire crackers waiting to go off if you do not follow the rules properly. That is the reason for battery management systems that are critical..

Personally, if you HAVE to ask on a Internet forum for advice on these, you ARE way over your head.

One must ask the question as to why you think you want to go this route..

To save weight?

To save on size per Ahr?

Spend more money?

Or to just sound so cutting edge "cool" when someone asks about your battery system?

Honestly, the weight savings over cost, size, Ahr capacity is just not there.

Two pairs of 6V GC batts will cost $320 and deliver just under 500 Ahr of capacity..

LiFePO4 batteries to get that capacity is going to cost a small fortune, example.. HERE is one for $100, has capacity of.. "Lead-Acid Replacement Range: 10-14(Ah)"

To get the 600 Ahr you desire you would need 60 of these batteries at a whopping $6000!!! Granted there most likely higher capacity examples but I really don't feel like digging any further..

Buy some solar panels, several AGMs and call it a day while pocketing the money you saved by not buying LiFePO4s..

[Salvo]

Have you looked at SmartBattery SB50?

They have all the current sharing electronics already installed.

http://www.lithiumion-batteries.com/products/12-volt-lithium-ion-batteries/12v-50ah-lithium-ion-batt...

You need to add extra electronics with the batteries you listed. Have you seen this?

http://www.electriccarpartscompany.com/1-60-Batteries-Per-BMU-br-EV-Battery-Management-System-BMS-br...

[rexlion]

For those who are wondering, LiFePO4 is Lithium Iron Phosphate chemistry. Considerably safer than the "lithium ion" (a generic term, in this instance probably Lithium Cobalt Oxide) batteries we hear about in the news lately, burning up the hoverboards.

But my only experience is with the 3V LiFePO4 cells I use in one of my flashlights. Each cell is charged in its own charger bay. No help for what the OP is doing.

[pianotuna]

My virus checker prevented this page from loading. Be careful.

Wo.ody wrote:
I do understand it would require a battery management system such as the Orion JR unit like this: http://www.orionbms.com/products/orion-bms-jr/

[pianotuna]

For an inverter go with a good name and make sure it is a hybrid type. Both Victron and Magnum make a 48 volt product. The Magnum is in the region of $1700 plus the cost of a remote control.

I know 2oldman is having great luck with a 48 volt stand alone Cotek inverter. But he charges mainly from solar.

Supply the 12 volt needs from a DC to DC converter. Victron makes one.

[pianotuna]

My understanding is that the battery balancing system ought to be integrated right into the battery bank, for a good LI system.

The one deal breaker for me is that LI can not be recharged below -20 c (-4 f).

I do urge you to reconsider solar even though you say you are in the shade. I do get 3 amps of charging in the rain. True, it is not a lot--but it is twice the 'rule of thumb' for parasitic loads. So 5 hours of shade garners 10 hours of parasitic loads.

[pianotuna]

Hi,

Thanks for the compliment but I've learned LOTS from other RV folks.

Here is a link to the rather special spreadsheet which includes an energy audit, that N8GS has created. It may suggest a good battery size and covers pretty much every device that anyone has in an RV.

spreadsheet by N8GS

Wo.ody wrote:
With a clean sheet of paper and from scratch, I'm trying to identify all the required electrical components required to create a "heavy duty charging system"