Trojan lithium drop in replacement

[KTP]

It looks like from Trojan's facebook video of the manufacturing that they are using round cells. I count 25 cells in each of the packs which seems weird. I would have expected 24 or 48. I can't see any markings to identify them.

[CatNewBee]

Originally Posted by KTP

It looks like from Trojan's facebook video of the manufacturing that they are using round cells. I count 25 cells in each of the packs which seems weird. I would have expected 24 or 48. I can't see any markings to identify them.

probably 25 parallel and 4 blocks in series to get 12v

[CatNewBee]

Originally Posted by ronstory

Are those the winston cells?

yes, winston makes among other chemistries LiFeYPO4 cells, they are the popular product, widely used.

The LYP are for storage and house batteries, the LTHP are designed for mobility applications (comparable to GEL vs. AGM)

[ronstory]

Cool, just looked that up on their website. Not sure I believe that spec, since that would be a breakthrough to charge Lithiums at full spec at -40C.

Considering a breakthrough normally get a price premium... since their prices are the same as Calb and others, I'm going to follow the "too good to be true" mantra. YMMV

Trojan's Battery spec makes sense to me since showing a reduced charge rate as they dip below freezing. Characterized behavior get interesting at the edges.

[KTP]

Originally Posted by CatNewBee

probably 25 parallel and 4 blocks in series to get 12v

Right! Duh. I can see now how they are packed in the group 27, flipped up sideways in 4 stacks of 25 paralleled cells. Those must be about 2.5 inches long then?

[Delfin]

Originally Posted by KTP

Ah or Wh?

You are not saying a Lithionics 24v 300Ah battery is $3000 are you?

Watt hour would be more clearly stated. From memory, my 600 Ah @ 24vdc was $14k with the BMS, or around $1000 per Kw hour. Same as the Trojan price quoted.

[Delfin]

Originally Posted by KTP

Nevermind, the 24V 300AH battery is about $8,000 to $9000

A little more expensive per watt-hour than the trillium

If there are no bugs in the initial launch the trillium is looking really top notch right now. The safety features and IP67 rating make strapping together some bare cells with duck tape and hope seem stone age.

Correction to the above....I paid $7k each for two 300 Ah 24v Lithionics packs.

[CatNewBee]

Originally Posted by Delfin

Correction to the above....I paid $7k each for two 300 Ah 24v Lithionics packs.

not too bad, competitive to the Winston cells price for capacity wise.
The only disadvantage I see, is they are build from small round cells instead of large prismatic blocks, what complicates the dessign of massive paralleled cells, they need cell fuses... and obviously the BMS is pre-set by the manufacturer and aledgedly not adjustable.

[tanglewood]

I think the biggest risk associated with these "drop in" batteries will be:


1) Consumer's failure to adjust charge outputs, resulting in unexpected battery disconnects.


2) Battery manufacturer's motivation to widen the operating range of the battery to mitigate #1, and consequently shortening the battery life. There are already hints of Trojan doing this with very wide operating temps, and very wide operating voltages.


The advantage is that it will probably force down pricing across the board which will be good for everyone.


It will be real interesting to check back in 5 years and see how this has gone.

[john61ct]

To me "Drop-in" should be reserved for sealed packs without access to the actual cell terminals, nor any communications between the internal BMS and any higher-level monitoring or control systems.

Like "solar generator", Drop-in is an inherently deceptive marketeering term, the whole point of which is to let noobs think it's OK to use old-school lead infrastructure, no external BM nor BMS, no adjustable charge sources etc.

Between those and full-fledged "packaged systems" like the Trillium, perhaps something like "sealed system pack", or "hybrid system drop-in"?

[NahanniV]

These seem to be available now.

But I can not find any information about the CAN bus monitoring ?

I would be installing into an area that is not easily accessible and would not be able to easily access the built in display.
Is there a CAN bus display that can do this ?

[CaptainJohn49]

Originally Posted by ronstory

Cool, just looked that up on their website. Not sure I believe that spec, since that would be a breakthrough to charge Lithiums at full spec at -40C.

Considering a breakthrough normally get a price premium... since their prices are the same as Calb and others, I'm going to follow the "too good to be true" mantra. YMMV

Trojan's Battery spec makes sense to me since showing a reduced charge rate as they dip below freezing. Characterized behavior get interesting at the edges.

This is incorrect - the operating temperatures are -20C to 60C or -4F to 140F.


The storage temperatures are -40C to 60C or -40F to 140F.


Still impressive. I have a Trojan 8D AGM still going strong. Will consider the lithium when the time comes.


One thing that I don't see mentioned that I think is important is with AGM or FLA you only get 40 - 50% of battery capacity before you have to recharge. With lithium you get close to 100% or the power therefor you only need 1/2 of the batteries of AGM or FLA.



Another advantage is weight. My 8D AGM weighs 161 lbs. and has 230 AH vs 2x lithium group 27 batteries that together would have 220 AH and weigh together 60 lbs. Now as a mooring weight the 8D is better but the lighter weight of the Li-ion would be an advantage on a boat.


Taken as a whole a better way to measure Li-ion batteries would be to take the usable power (AH) vs AGM or FLA batteries. Using that metric Li-ion are a reasonable alternative. Although not exact, you could have 1/2 the batteries and 1/5 the weight and still have the same usable power.


Another great feature of Li-ion is the fast recharge times. The battery will absorb charging energy at almost full power cutting charging times to minutes not hours. Steep charging cycle and flat discharge cycle so that you get a full 12v until it drops off a cliff.


Just my 2 cents worth.


CaptainJohn49

[ronstory]

Capt J49... Ok i'm not sure how to respond. Please re-read posts 88 to 94. I was referring the optimistic ratings of the Wistron cells. I'm a fan of the Trojan batteries (per spec)... but that needs real world feedback to make it true.

Before you post, please read.

[CaptainJohn49]

Originally Posted by ronstory

Capt J49... Ok i'm not sure how to respond. Please re-read posts 88 to 94. I was referring the optimistic ratings of the Wistron cells. I'm a fan of the Trojan batteries (per spec)... but that needs real world feedback to make it true.

Before you post, please read.

Because the topic was "Trojan lithium drop in replacement" I thought you were talking about the charging and operation of Trojan lithium. I see now that the post (#93) prior to your post (#94) had mentioned Winston batteries. Sometimes easy to get confused. Almost like conversations at parties, your not certain who's talking to whom.



CaptainJohn49

[CatNewBee]

In the past many DIY LFP builder experienced an over-provisioning of 20..30% with the Winston cells in regards of capacity on fresh cells. On my fists tests I also had similar findings between full and empty (1200Ah usable capacity on 1000Ah cells before between the shoulders (3.65V -> 2.9V / cell), I have expected 900Ah.

I guess, this is one way to guarantee the 5000 cycles at DOD 80%, you have some reserve-capacity upfront, so the cells do not degrade just 20% on 5000 cycles, but can loose 33% in fact during this time still delivering to the specs.