6 v GC batteries versus 12 v lithium deep cycle batteries

Some day the Taiwanese company MEANWELL will bring out A to D management of individual cells with corresponding I ratings for amperage. Silicon Carbide MISFETS now can easily handle hundreds of amperes of current.

I won't be around to see whether or not millions of acres of solar panels are going to address daytime only battery recharging.

Take a look at 50 Kw prime power generator sets to see the significance of perspective for recharging. It takes a 6 cylinder turbocharged big rig diesel engine to drive a single generator at 1,200 RPM. Better yet, divide the Megawatt total of Boulder dam into 50Kw segments.

Then do line transmission math workouts. It's going to be a multi-trillion dollars project for California alone to upgrade.

jaycocreek wrote:

but BattleBorn deliberately derates their 100 amp-hour to 100 from a "real" 120 amp-hour.

Please explain this as Will Prowse tore one down and did the math off the actual cells which in turn produced 1305.6 watt hours compared to there advertised 1280...Not that much difference really certainly not 20 amp hours IMHO..

He said each of the 120 cells has 3.4 AH and used 3.2v to get 10.88Wh.

He then did 120 x 10.88 = 1305.6Wh

DOT shipping "nominal" voltage is 12.8 so 100AH x 12.8 = 1280Wh. He then said this meant the BB had "extra capacity"! (insert own comment on why he acted so happy to "learn" that) He did not give the "real AH".

But if each cell is 3.4AH (don't know where that came from), then each of the four packs of 30 cells is 30 x 3.4 = 102AH and in parallel, that is 102AH for the battery

Note that 12.8 x 102 = 1305.6. (of course)

IMO you should use the voltage for the the capacity when full , said to be 13.6 for LFP to get your Wh, so if it is really 102AH then Wh would be 1387.2.

But voltage drops to 13.3 when a load is applied, so since say 99% SOC is then 3.3, then 100.98 x 13.3 = 1343 Wh

None of which says how low you can go while deciding on the "usable AH".

It’s not clear to me why the relentless advocacy of SiO2’s creeps into EVERY LFP enquiry (a topic ‘re-direct’ malady..), but contrary to the non-user, speculative knowledge base of a few SiO2 purveyors (flat-earthers who trade in LFP mythologies - e.g. finicky, huh??), LFP’s are in fact quite liberating - I pay FAR less attention to my 200amp/hr LFP (more similar to grid than to battery power) than I formerly did after 15 yrs of 215 amp/hr (gross) GC lead-acid management...Why??

1) Faster charging (expediting peak solar harvest recovery periods...).
2) Virtually eliminating inverter and furnace low voltage shutdowns - a near voltage stability.
3) Much more ‘usable’ capacity for the same size battery and of battery compartment constraints.
4) No routine need to fully recharge!
5) At least half the weight of chemically sluggish FLA’s.
6) Much longer number of charge cycles and warranty (10yr warranty not uncommon).
7) No equalizations.
8) Uber low self-discharge rate, per this regard second to none.
9) ‘Independent’ White Paper evaluations are ‘readily obtainable’ (Google, et al).

Though it’s apparent that the SiO2 interlopers are fully committed to their cause (in which extended cold WX is their major cause), in light of the above and within the broader user marketplace (e.g. exempting extended extreme weather conditions*), SiO2’s are overpriced, and poorer performing (similar to lead-acid), thus a poor utility and value quotient for the majority of intended users...

Curiously, some may argue that “the jury is still out on LFP’s” (in spite of reputable independent evaluations, evidenced by numerous long Mfg warranties), while simultaneously dismissing this very same standard (or lack of??) for SiO2’s...

Just Saying, :?

*Note: easily mitigated via optional LFP heater circuitry.

3 tons

There are both advantages and disadvantages not counting price
Li Type batteries are fairly fussy eaters. the better ones have on board charge regulation... And some companies say "Do not connect in parallel". (Others I do not know about my LI battery is "Do not parallel" (not a problem)

They also have the advantage of
LA run down down down stops
LI runs run runs runs runs stops
You can run them down ever farther and they hold almost constant voltage till nothing.. this is both an advantage and a disadvantage.

LI is way way way way lighter (Major advantage)
if money was no object it'd have converted.

but BattleBorn deliberately derates their 100 amp-hour to 100 from a "real" 120 amp-hour.

Please explain this as Will Prowse tore one down and did the math off the actual cells which in turn produced 1305.6 watt hours compared to there advertised 1280...Not that much difference really certainly not 20 amp hours IMHO..

Sorta like comparing a Ford Focus versus a Rolls Royce Phantom.

pianotuna wrote:

theoldwizard1 wrote:
Ignoring price (very hard to ignore), Lithium Iron Phosphate (LiFePO) batteries are far superior to any lead acid battery for 2 reasons :

• You can discharge them down to almost 0% SOC with no damage (more usable energy for the same rating)

I'm sure Stircrazy would subscribe to this view point--but BattleBorn deliberately derates their 100 amp-hour to 100 from a "real" 120 amp-hour.

So far as I am aware the rest of the Li makers don't protect the end user this way.

Could it be the battery management systems are keeping the bottom 20% from being used?

https://www.lynaclithium.com/wp-content/uploads/2020/10/12.8V-100Ah-True-Series-Quick-Sheet.pdf

What is TRUE Series?
True usable power rating system. Unique to Lynac Lithium, True Series
describes the amount of Real Usable Energy you can expect from our batteries
based on 80% Depth of Discharge. If it says 100Ah on the case, you get 100Ah!

pulling the post because of the reaction of several members. I remain open to PM.

all said above,

12V LFP advantages

lighter, smaller, 100% usable capacity instead of 50% and for much longer life, higher charging aceptance, able to take much higher charge rates and discharge rates

disadvantages

dont like charging under -4 degrees (C) or discharging under -20 (C), can cost more but that is alomost equal now if your comparing to high quality GC batteries and cheeper if you can build your own.


don't PM people who say "PM me so other people dont see me spreading half truths"

Steve

str8shooter_mn wrote:
Disregarding price, is there a distinct advantage having 12 volt deep cycle batteries over the standard 6 volt golf cart batteries. These are for house batteries, have four, wired to provide 12 volts. On a Thor Tuscany pusher.

So with four GC’s you are talking about a combined 430’ish gross amp/hrs (about half that amount for net usable), which translates to about 200 amp/hr worth of LiFePO4’s...

Theoretically, a LiFePO4 can charge at up to a full1C rate, but in practice are just as happy to charge at whatever lower rate your converter-charger or solar can deliver...If you have a Progressive Dynamics 3 stage (or 4 stage w/equalization) charger, all that is needed is to switch it into the 14.4v Boost mode via the Charge Wizard (if so equipped)...

Alternator charging can be another thing, so to protect it from overheating (due to the higher charge receptivity of LFP’s) you’d either want to add a dc to dc charger (compatible with your particular alternator), or do as I did (as a desert camper) and just charge mostly from solar...Since you have a pusher I might assume that you spend lots of idle time with hook-ups, thus solar may meet your remaining needs...

FWIW, getting the required 14.x volts from a newer generation ‘Smart alternator’ may not be a viable option - a battery direct connect, current limiting dc to dc converter will overcome this while protecting the alternator....

Just a few ideas,

3 tons