Drop in Lithium 12 months on (long Read)

Ubif · Veteran Member

Drop in Lithium 12 months on (long Read)

Tony Bev · Guru

Thanks for that info, Mark (Ubif), I for one, do appreciate your feedback

Can I please have the name/brand of your 20 AMP BCDC also Lithium capable charger

Thanks

KJB · Guru

Thanks for passing on your experienced, clear and factful report.
I am sure it has answered a lot of potential questions out there.

Ubif · Veteran Member

Hi Tony
All parts excluding solar charger are from RTM and Digitech branded, battery 3 years warranty others 1 year.
BCDC has solar input as well but I opted not to use it, it also has ignition control which I wired to van park lights
as I always have them on when towing, 30 amp solar controller from ebay and same as WA seller uses for $90
I carry an extra one as spare as it was cheap
cheers
Mark
PS. RTM is part of the Jaycar group so good Aust wide cover for warranty claims if needed

Tony Bev · Guru

Thanks for that info, Mark

It is appreciated

Bruce Mc · Veteran Member

When you say BCDC charger is this the same ad DCDC?

Ubif · Veteran Member

Hi Bruce Mc
yes some call BCDC others DCDC
I Myself think it should be DCDC as this is what it is doing

cheers Mark

Bruce Mc · Veteran Member

Thanks. Just wanted to be sure I am on the same page as you.

stoney123 · Senior Member

Check the recommended load your battery supports, I see you drawing high loads, some lithiums cannot do high load. I also use high load but battery can handle it.

Ubif · Veteran Member

Hi Stoney123
No I don't draw very high loads I just mean that the battery has not got below %50 of capacity
constant load is 12v compressor fridge ,water pump, lights, radio, TV, and USB charging even if all were going at once
the load would be no more than about 15amps
cheers
Mark

Jaahn · Guru

Hi Mark, smile

A clear and concise report and same good answers to question. AHHH if only everyone would do that for us. cry

Thanks for that and it will is interesting for a lot, like myself, who might move that direction next time. Thanks again. biggrin

Jaahn

dorian · Guru

As I see it, the question as to whether "drop in Lithium batteries would work" was not addressed. The OP replaced a "wet cell" with a lithium battery, but he also replaced all the charging devices, ensuring that they were lithium capable. I would argue that lithium batteries cannot be direct, drop-in replacements for lead-acid chemistries.

Ubif · Veteran Member

Hi dorian
yes I did change my charging equipment. But I have included this information to show that it can be done without spending $2 to $3 thousand dollars for a small system.
I have been a qualified electronics tech for over 45 years and could design a BMS or what ever (designed and built my first computer in 1972 before Tandy or Dick Smith)
at some point in time you need some trust in the documentation supplied by sellers as they need to keep in business.
who is to say that I buy a system made else where that their BMS is any better than the one sold in my battery? if I used the cheapest battery then I could have done the whole thing for
under $1000. I believe you would need to spend more if you need high amp draw for an inverter to run microwave etc. not all GN's need this.
cheers
Mark

Peter_n_Margaret · Guru

So, after spending this money, what can your system do that it could not do for you before?
Cheers,
Peter

Ubif · Veteran Member

Hi Peter n Margaret
for one I have a new compressor fridge so my wife is not worried by food temp.
we have only tested for 14 nights off grid as we had to go home for a medical problem with my dad I think we could go for more ( I am not talking about food or water still need to go to town for that)
I saved a lot of weight. I am not trying to say my system is the best and it is not for everyone I have just reported on what I did to solve a problem and how it has worked for me
everyone needs to take in all information they can get and then decide for themselves what they want to do. I am not trying to sell or sway any one. just give the facts on what I have found.
cheers
Mark

Peter_n_Margaret · Guru

Except for the weight reduction (if that is critical), you can do everything you do and a lot more with almost any battery type, for a great deal less expense.

I feel that lithium batteries have become a bit of an expensive fashion.

Use them for what they are good at (high current draw and lower weight) but if you don't need those 'properties, why spend the dollars?

Cheers,

Peter

Hylife · Guru

Peter_n_Margaret wrote:
Except for the weight reduction (if that is critical), you can do everything you do and a lot more with almost any battery type, for a great deal less expense.
I feel that lithium batteries have become a bit of an expensive fashion.
Use them for what they are good at (high current draw and lower weight) but if you don't need those 'properties, why spend the dollars?
Cheers,
Peter

A little late to reply (haven't been on for a while) but LiFePO4 are actually now cheaper than old style Lead Acid batteries not just to buy but especially long term.

Yes, that's right, you did read correctly, "cheaper"

How do I figure that? Simple.

1) lead acid really only gives you 50% of their rated capacity without seriously diminishing lifespan with long term use.
EG, 2 x 100AH batteries (200AH) really only gives you 100AH before the voltage drops to a level where you should stop discharging.
A pair of quality AGM 100ah will set you back at least $299 each, possibly more.

2) A 100ah LiFePO4 battery now only costs around $550.
LiFePO4 gives you 95% of its rated capacity with negligible voltage change.

3) All batteries have a limited number of charge-discharge cycles.
Quality AGM at 50% Depth of Discharge (DOD) you can expect 400 to 600 cycles (far less if you go deeper a few times).
Even basic LiFePO4 at 95% DOD you can expect 2000 to 3000 cycles and up to 10,000 cycles at 50% DOD

So, for the same total amps output a LiFePO4 is not only $50 cheaper to buy but it will last at least 6 times longer.

Oh, and 2 x quality AGM 100ah weigh approx. 70kg, whereas, 1 x 100ah LiFePO4 weighs around 13kg, allowing you or SWIMBO to pack an additional 55kg of "stuff"!