Trojan lithium drop in replacement

[john61ct]

Originally Posted by KTP

Hmm, based on that link it does look like Trojan is totally just slapping a label on the K2 battery, at least the 110 (111) amp hour version. K2 doesn't list a 92 amp hour version so I guess it is possible that is made special for Trojan

Could be Trojan is just being more conservative in its capacity rating.

Much deeper a reputation to protect, and the top tier LFP cell makers have set a high bar, customers are used to getting higher actual Ah than rated.

Trojan is big enough the quality specs the set may be much better than what K2 makes for their own label.

Or their management may want to milk their brand rep for short term profits and spec'd to a price point so the Trojan version will turn out to be worse than K2 labeled!

Only time will tell, general impressions over time, anecdotal incident reports, or ideally, objective data from testing by knowledgeable members like MS.

[john61ct]

Originally Posted by KTP

The pricing I have found for a Lithionics 12.8V 150AH battery is $2900 each. That is $1.51 a amp hour.

…

What do you think John?

I think that's over $19 per Ah

> The Trojan/K2 110AH battery at $1100 single quantity works out to be about $0.79 per amp hour.

I think that's $10 per Ah

_______
And let's make sure all voltages are factored to a 12V nominal, or

use $ per kWh for consistency, LFP at 3.3 per cell a decent nominal value.

[john61ct]

Note that neither Lithionics nor Victron manufacture their actual LFP cells.

BMS systems design and integration, distribution and dealer support is their added value, for a large - and well-deserved - markup of course.

K2 seems to be unique afaict, from raw cell through consumer-direct retail of packaged systems plus OEM for re-labelers.

Winston, CALB, GBS, A123 & Sinopoly may well do systems-level contracts for big customers (domestic military almost certainly) but yet to see full with-BMS systems targeted to the consumer market.

But I've yet to come across indications of longevity quality wrt K2 from a source I trust.

Yes, winning US Defense contracts presumably involved stringent testing, but then again maybe the use case is shallow cycling, or designed for a short replacement cycle like 5 years. . .

[KTP]

Originally Posted by john61ct

I think that's over $19 per Ah

> The Trojan/K2 110AH battery at $1100 single quantity works out to be about $0.79 per amp hour.

I think that's $10 per Ah

_______
And let's make sure all voltages are factored to a 12V nominal, or

use $ per kWh for consistency, LFP at 3.3 per cell a decent nominal value.

I meant watt-hr, I was just typing too fast to think :-)

I based the watt hour rating on 12.8V 150 AH and 12.8V 110 AH for the two batteries. $ per watt hour is the best as you say.

[KTP]

Originally Posted by john61ct

Or their management may want to milk their brand rep for short term profits and spec'd to a price point so the Trojan version will turn out to be worse than K2 labeled!

Oh I hope not. It is such a shame now when you go buy a tool like a Makita drill and find out it has been made super cheap in China to a low level of quality and is just selling on the brand name. There are some great companies who have just totally trashed their products by moving production to a cheaper location with lower quality control.

[Cpt Pat]

I queried Trojan about the warranty. I got this reply:

The warranty period is 4 years in a motive (mobile) application and 8 years in a stationary application. The warranty covers manufacturing defects and is not transferable from the original purchaser.

Be sure to get that in writing. I couldn't find that info anywhere on the Trojan site.

I presume the internal data logging is for warranty claims. It's a black box "flight data recorder," since the data is inaccessible to the consumer.

In most installations, I suspect, the battery will spend most of its time fully charged on shore power. This is not an optimal storage scheme for LFP batteries since they degrade when stored fully charged. Since there is a way to manually switch the battery offline during storage, using the top button switch, Trojan suggests storing it offline in a less-than-fully-charged state (preferably 30% SOC). I doubt my users will follow that advice.

My conclusion: too much complexity, too great a risk of inaccurate cell balancing from all those little cells in parallel, and a high likelihood of high self-discharge rates and potential failures from all the onboard electronics. While having a CPU-controlled BMS sounds cool, it "feels" to me like the Boeing 737 MAX problem: attempts at fixing an inherent weakness with software. I'm still sticking with my manually-balanced prismatics and custom BMS.

[john61ct]

And also missing if the warranty is full replacement or just a pro-rata credit.

In any case 4 years is a very low bar to clear, they're pretty safe in either case as long as there aren't huge defects in the design or mfg process.

I agree these are unlikely to deliver the longevity of a simpler prismatic installation managed by a clueful owner.

But probably good enough for the mass market not wanting to learn the details, except from a value for money POV.

[Paul L]

Sounds like the warranty is 4 years longer than a DIY system

[john61ct]

I've never considered warranty to be a significant decision factor wrt batteries anyway. At best just a minor indicator if I'm not already familiar with the parameters actually indicating quality.

[Paul L]

Originally Posted by john61ct

I've never considered warranty to be a significant decision factor wrt batteries anyway. At best just a minor indicator if I'm not already familiar with the parameters actually indicating quality.

Then why pick on Trojan for 'setting a low bar' with their offer of 4 years?

[john61ct]

I see no inconsistency, not "picking on" anyone.

Warranties in general are pretty useless as a decision factor, across this whole industry segment.

Written for marketing purposes and for a quality product very rarely relevant

This product included, they will likely very rarely need to pay out, even if the actual quality is very poor, compared to what I would like to believe it's capable of.

[Paul L]

Originally Posted by john61ct

I see no inconsistency.

....

You wouldn't. As you have zero experience with the product or similar product on a cruising boat it really doesn't matter.

[rgleason]

Trojan Battery Company’s new Trillium intelligent lithium-ion deep-cycle batteries are a direct replacement for standard lead-acid batteries, as well as other LiFePO4 batteries,

From their marketing.

I suppose any alternator connected to it has to have its own regulator that cuts the field current before the Trilium BMS HV relay is activated...

or would a Battery 24v DC to 12v DC Charger be adequate to dump the loads to a second FLA "starter" battery?


Other Threads:
https://sprinter-source.com/forum/sh...ad.php?t=74415

[john61ct]

I would not inflict that load dump on a device unless specifically designed to absorb it.

Personally can't see why a $20 lead batt wouldn't do, literally any will do.

There are of course more specific and expensive solutions.

Some VRs advertise building in the feature, but I never heard of anyone putting it to the test.

[mitiempo]

Best solution is a Fla start battery and an ACR. This is what Victron shows in their schematics - simple and it works.