D4 dual battery isolators - what options

While the Li Po batteries are the current "hero" of the battery world.
I have reservations using them in any circumstance fitted to the vehicle.

When these things let go you can wave goodbye to your rig and they let go at a surprising frequency over all manner of equipment.
On top of the "normal" failures through wiring faults etc. LiPo batteries are prone to violent flames/ venting from all manner of influences which conventional cells are not typically known for.

Our company now has procedures and equipment in place to help protect us from the multitudes of equipment fitted with LiPo failing.
In the last 12 months we have had 4 events. Prior to LiPo equipment we had none.

I'm sure many are happy campers. But for now, wouldn't be my choice for additional power.

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Originally Posted by strangy

While the Li Po batteries are the current "hero" of the battery world.
I have reservations using them in any circumstance fitted to the vehicle.

When these things let go you can wave goodbye to your rig and they let go at a surprising frequency over all manner of equipment.
On top of the "normal" failures through wiring faults etc. LiPo batteries are prone to violent flames/ venting from all manner of influences which conventional cells are not typically known for.

Our company now has procedures and equipment in place to help protect us from the multitudes of equipment fitted with LiPo failing.
In the last 12 months we have had 4 events. Prior to LiPo equipment we had none.

I'm sure many are happy campers. But for now, wouldn't be my choice for additional power.

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That may be true for Lithium-ion cells, but the LiFePO4 cells are considered very safe. Economically AGM's etc still do stack up better if life-time is not taken into account. But for anyone space or weight challenged, LiFePO4 are the answer. See https://en.wikipedia.org/wiki/Lithiu...sphate_battery

Besides, there are lots of Tesla cars running around safely, and lots of mobility scooters, and lots of electric boosted push-bikes etc etc.

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Originally Posted by strangy

While the Li Po batteries are the current "hero" of the battery world.
I have reservations using them in any circumstance fitted to the vehicle.

When these things let go you can wave goodbye to your rig and they let go at a surprising frequency over all manner of equipment.
On top of the "normal" failures through wiring faults etc. LiPo batteries are prone to violent flames/ venting from all manner of influences which conventional cells are not typically known for.

Our company now has procedures and equipment in place to help protect us from the multitudes of equipment fitted with LiPo failing.
In the last 12 months we have had 4 events. Prior to LiPo equipment we had none.

I'm sure many are happy campers. But for now, wouldn't be my choice for additional power.

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Your comments are interesting and point to the need to clearly understand the difference between Lithium Iron (LifePO4) and Lithium Ion (LiCoO2) the latter of which is the dangerous one. Recollect 2013 and a Boeing 777 to start with.

The chemistry and technology around the LifePO4 (Lithium Iron Phosphate) is considerable different from the Lithium Cobalt Oxide of the LiCoO2 batteries and there remains a considerably need to help users of both types understand how to manage them.

To understand this I suggest going to this link [ame]http://www.redarc.com.au/images/uploads/files/colriversfeb.pdf[/ame] and reading Collyn Rivers informative article on the subject.

The failures you have described sound more like LiCoO2 battery issues as I am not aware of any in the LifePO4 area apart from where home builders have put together cells to make a battery without understanding the specifics required to correctly engineer, charge and maintain them

I am completely comfortable with the safety of the LifePO4 battery and charging systems that are commercially available. What we are continually finding with this subject is the need for the industry to actually put some decent information out to help potential purchasers sort out the chaff from the wheat.

Rob

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Originally Posted by Silenceisgolden

Sorry Tim, I think you are mistaken there.

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Hi again Silence, with one of my systems fitted, you have 90Ah available, but to get that same usable capacity, you need to fit a 110Ah LiFePO4 battery, which would be way, WAY to big to fit in the auxiliary battery compartment.

So you would have to fit it in the rear cargo area.

This will now give you a lose of space, additional weight, a huge additional expense and all you have done is equaled the usable capacity of what one of my standard DBS kits can already do, for a fraction of the cost.

Furthermore, you will NOT be getting any benefit for your cranking battery.

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Originally Posted by drivesafe

Hi again Silence, with one of my systems fitted, you have 90Ah available, but to get that same usable capacity, you need to fit a 110Ah LiFePO4 battery, which would be way, WAY to big to fit in the auxiliary battery compartment.

So you would have to fit it in the rear cargo area.

This will now give you a lose of space, additional weight, a huge additional expense and all you have done is equaled the usable capacity of what one of my standard DBS kits can already do, for a fraction of the cost.

Furthermore, you will NOT be getting any benefit for your cranking battery.

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Hi Tim, a Winston 100Ah (3.6 volt) battery is 218x179x62 and weighs 3.6 kilograms. Four are strapped together giving a battery 218x179x248 weighing 14.4 kilograms with a usable capacity of 80 Ah, equal to 160 Ah of AGM batteries. See EV-Power | WB-LYP100AHA LiFeYPO4 (3.2V/100Ah WIDE)

Tim, I am not a great fan of these batteries, they are still a bit new, while AGM's are fully known mature technology. But they DO have more usable energy per unit weight and size than AGM's.

For a starter, the instant I see Lithium battery suppliers making statements like "a lithium battery's 60Ah = 160Ah of AGMs" as it is pure bolox, I do not trust another thing they make claim to.

A 100Ah lithium battery has 80Ah of usable capacity, just as a 100Ah STANDARD AGM battery has 80Ah of usable capacity.

Next, your specialised lithium battery setup still falls 10Ah short of the 90Ah my Off-The-Shelf setup can provide and as far as weight saving goes, you haven't added the cost, weight, and space required for the special charging needed when using lithium batteries in any motor vehicle!

And your setup has none of the other benefits my systems offer!

Your math just does not add up!

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Originally Posted by drivesafe

For a starter, the instant I see Lithium battery suppliers making statements like "a lithium battery's 60Ah = 160Ah of AGMs" as it is pure bolox, I do not trust another thing they make claim to.

A 100Ah lithium battery has 80Ah of usable capacity, just as a 100Ah STANDARD AGM battery has 80Ah of usable capacity.

Next, your specialised lithium battery setup still falls 10Ah short of the 90Ah my Off-The-Shelf setup can provide and as far as weight saving goes, you haven't added the cost, weight, and space required for the special charging needed when using lithium batteries in any motor vehicle!

And your setup has none of the other benefits my systems offer!

Your math just does not add up!

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Tim, JamesAdelaide was concerned about space and there is no doubt at all that LiFePO4 batteries give more energy per unit size. Just look at a few websites, it is true and un-arguable.

Also, on ANY battery website you will see that taking 80Ah from 100Ah AGM's or similar 100Ah batteries will hugely shorten their lives. 80Ah CAN be safely taken from 100Ah LiFePO4's - others can not be done safely. This is absolutely common knowledge I would expect you to know - check ANY battery manufacturers website.

Tim, one size does not fit all. I am sure your system is fine, and no doubt the simplest of all to install with your excellent kit, but it is not for everyone. Some users will need a bit more and they have the right to know what the alternatives are. LiFePO4 with Redarc is no doubt more expensive, but for those who want more it may be justifiable. After all, the D4 itself is pretty high tech! Cheers Tim, keep smiling!

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Originally Posted by Silenceisgolden

LiFePO4 with Redarc is no doubt more expensive, but for those who want more it may be justifiable.

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My last post on this subject.

Not once have you shown how anybody gets more than a bigger bill.

People actually get less with your suggested setup but pay a huge amount more to get less.

I'm all for new things that improve what ever we are doing or trying to do.

But Lithium battery setups in D4s are not a step forward, and are only relevant, as I stated much earlier in this thread, if you have a specific need for them.

Everybody else just looses heaps of money unnecessarily if they go down that road.

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Originally Posted by drivesafe

For a starter, the instant I see Lithium battery suppliers making statements like "a lithium battery's 60Ah = 160Ah of AGMs" as it is pure bolox, I do not trust another thing they make claim to.

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Tim, I think you misread this (my bolding of the text):

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Originally Posted by Silenceisgolden

But they DO have more usable energy per unit weight and size than AGM's.

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That was my understanding - for the same Ah rating, the lithium is a smaller package than the AGM.

Is that not correct?

Hi Ron and no the claim put forward by many of the Lithium battery sellers is that for an AGM to be able to supply similar Ah for the same number of cycles that a lithium battery can, the AGM must not be discharged below 75% SoC or the cycles will reduce.

So you therefore need more AGMs than lithiums, to be able to supply the same amount of Ah.

This is correct, but like most seller's hype, the full facts are slightly different.

These sellers of lithiums neglect to point out that AGMs can be bought for a hell of a lot less than comparable sized lithium batteries.

So if you cycle the AGMs down to 20% SoC, the AGM is not going to give you anywhere near the same number of cycles as a lithium, but because AGMs can be a fraction of the cost, you can still get similar usable Ah per dollars spent, but spread over a number of batteries, and your cost is spread over a long time period as well.

Here is another fact most people are unaware of. Just like lead acid batteries, most lithium batteries suffer from reduced life span if you cycle them continually down to 20%. You only find this type of data if you know where to source it from.

Furthermore, I have been working with a number of different brands of lithium batteries for around 5 years now, and there is still a lot of misinformation out there and a lot of crappy lithium batteries ( just like some crappy lead acid batteries ) so again, you need to know where to get correct info.

To get honest info about lithium batteries, you should source the info from US lithium battery manufacturer's web sites and take little notice of what sellers claim.