Comment: Solar Power

Is it possible to use lithium batteries in a solar set-up or do they require special charging. I'm running 2x120w panels and a 130ah agm deep cycle battery. Lithium is lighter and they recharge quicker with the batteries outlasting agm's. Space,weight and size is an issue but if theses batteries are ok i'll switch over asap.
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Reply By: Nutta - Monday, May 20, 2013 at 19:08

Monday, May 20, 2013 at 19:08
I think thats a no no.

I know my ryobi lithiums have some sort of circuitry in them to control the charging unlike other battery packs, I'm sure someone can explain it better soon though. Cheers
AnswerID: 511460

Reply By: Batt's - Monday, May 20, 2013 at 19:19

Monday, May 20, 2013 at 19:19
It shouldn't be a problem because they can handle short charges better than other batteries and recharge quicker. There is a camper trailer busness that is putting them in his trailers these days not sure which one now. Can I ask how much you paid for per battery and where you got them fromI found a site a while ago they wanted around $1,300 each pretty expensive.
AnswerID: 511463

Follow Up By: phil h10 - Friday, May 24, 2013 at 07:13

Friday, May 24, 2013 at 07:13
http://ev-power.com.au/webstore/index.php/12v-lifepo4-batteries/12v-lifepo4-batteries/12v-4-cell-040ah-lfp-battery-module-1.html
Try this link as the batteries are around the $350 mark...cheers
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FollowupID: 789998

Reply By: KenInPerth - Monday, May 20, 2013 at 22:56

Monday, May 20, 2013 at 22:56
I don't claim to be very knowledgable in this area, but as far as I know the charging technology for Lithium is different to that required for Lead Acid / AGM etc.

I found this snippet on a Battery site which tends to indicate they are designed as direct replacements for Lead Acid, but incorrect charging methods (ie from Lead Acid chargers) can result in long term damage. Now some may claim that they are tryng to sell their chargers, but I would tend to agree there is a different charging regime required.

It would be an expensive mistake probably not to take care of the charging requirements of them .. I dare say there are solar chargers being made specifically for Lithium batteries.


CHARGING:

The "UltraEnergy" energy storage battery is intended to be used as a direct replacement for lead acid batteries used in energy storage systems. It is best for the "UltraEnergy" battery not to be trickle charged but to use advance chargers that turns OFF charging current when the battery is completely charged at 14.6V. StarkPower sells "Smart" chargers for lithium batteries. Using lead acid chargers that charges up to 16V, along with leaving them ON, will damage the Lithium battery over extended time.
know
AnswerID: 511486

Reply By: Nomadic Navara - Tuesday, May 21, 2013 at 00:27

Tuesday, May 21, 2013 at 00:27
Yes there are plenty of members of other forums running them. They are like any other storage battery, you need a battery charger that is tailored for them. if you have an existing system you may have to charge your chargers to suit.

Kimberley Kampers use them extensively these days. That link takes you straight to their Lithium battery page.

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AnswerID: 511491

Follow Up By: PhilD - Tuesday, May 21, 2013 at 05:43

Tuesday, May 21, 2013 at 05:43
Lithium technology has advanced greatly in the last few years, so there are quite a few brands of 240 volt, MPPT, alternator to battery, dcdc, etc chargers that are selectable for lithium batteries. The charging rate is 14.6 volts, but a very good battery monitoring system with the lithium battery offers the protection needed. I have found EV Power in WA have fairly priced and well put together systems ( no connection).
Phil
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FollowupID: 789743

Follow Up By: KenInPerth - Tuesday, May 21, 2013 at 11:37

Tuesday, May 21, 2013 at 11:37
I have to admit I was not aware of Li technology advancing to the state it has for 12V systems - but obviously still at a fair cost. I note things like "4 times the life" but at the moment it seems to be (much?) more than 4 times the cost to implement - the main advantage being re-charge time is it ??

I know it probably comes back to quality of manufacture, maybe quality of storage for transport, and other factors very different from putting a couple of these in an RV, but there have been two 747 cargo planes destroyed that were linked to carriage of Lithium batteries, and also overhead locker fires in aircraft as a result - and Lithium fires have to be fought by putting the flames out and then cooling them so they do not re-ignite and not by normal halon type extinguishers. Apparently they are susceptible to internal short circuits that causes this and are still considered "dangerous goods not to be checked in" (source: Australian Flight Safety )

Again I stress this may have a lot to do with quality of manufacture and is applicable to small appliance batteries - hopefully what they are producing for more rugged environments like RV's has advanced to the point of this not being a risk.

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FollowupID: 789758

Reply By: Member - Keith Berg - Tuesday, May 21, 2013 at 15:33

Tuesday, May 21, 2013 at 15:33
Phil,
I thing you also need a low voltage circuit breaker, so that you won;t damage the battery by drawing it down too far. EV Power can help you with all of that. I have been talking to them about powering m our camper and they are very helpful.
AnswerID: 511519

Reply By: KevKim37 - Wednesday, May 22, 2013 at 00:35

Wednesday, May 22, 2013 at 00:35
The new type Lithiums being used by other forum members are not "Lithium Ion" but a different construction called "Lithium Iron or LIFE P04" and as the others have mentioned they are close to half the weight and up to 80% of capacity can be drained and still deliver, also require BMS (Battery Management Systems for individual cell readings and decent battery chargers.

I am keeping an eye on their developments for future usage when my 4x100a/h AGM's drop off. From what I have read so far looks good for the future as the prices hopefully drop.?

Cheers Kev.
AnswerID: 511550

Follow Up By: Nomadic Navara - Wednesday, May 22, 2013 at 09:53

Wednesday, May 22, 2013 at 09:53
Quote -"also require BMS (Battery Management Systems) for individual cell readings and decent battery chargers."

In the different forums I am on there is a lot of harping on about the special monitoring needs of lithium batteries. I would not woor too much about these. Yes in the early days when early experimenters were building their own batteries from individual cells they had to worry about the problem.

These days the BMS is built into the batteries. It's there and you don't see it working. The new battery packs you purchase are ready to go and you need give them no more attention than you should be giving to your lead acid batteries.

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Reply By: Member - Gerald V - Wednesday, May 22, 2013 at 13:57

Wednesday, May 22, 2013 at 13:57
I have two LFP (LifePO4) packs in our car/camper rig (http://ev-power.com.au/webstore/index.php/12v-lifepo4-batteries/12v-lifepo4-batteries/12v-4-cell-040ah-lfp-battery-module-1.html). Charge off alternator and solar no problem with standard SLA charge regulators (no fancy charge hardware required). I have a low volt cut out to protect the batteries. I 'top up' with a C-Tek charger from time to time.

Extra cost - yes. Advantages: Low self discharge, longer overall life, larger number of cycles for life of battery, ability to discharge down to 0% without fearing damage, lighter, smaller.

You will comfortably be able to replace your 130Ah AGM with a 100Ah LFP (assuming that you currently only discharge your AGM to the recommended 50%) since the LFP may be discharged down close to 0%.

Having had LFEs installed for 8 months now I won't go back to older SLA/AGM batteries.
AnswerID: 511586

Follow Up By: Member - Keith Berg - Friday, May 24, 2013 at 09:53

Friday, May 24, 2013 at 09:53
It is my understanding that discharging a LIPO4 battery below 90% can reduce its life by about 25% and that discharging to zero can fatally damage the battery.
I think that's why a low voltage cutout is recommended.
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FollowupID: 790003

Follow Up By: Nomadic Navara - Friday, May 24, 2013 at 11:27

Friday, May 24, 2013 at 11:27
Keith, did you not read the Kimberley Kampers link in my my message in FollowUp 4. That was not what Kimberley had gleaned from their studies or their experience.

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Follow Up By: Member - Keith Berg - Friday, May 24, 2013 at 12:51

Friday, May 24, 2013 at 12:51
Peter,

Here's what Kimberley say on Page 9 of their "Amazing Lithium Batteries Guide" E-Book:

"As a guide, if the battery is only discharged by 90% or less,
the number of charging cycles expected for a Lithium battery is
>1500 cycles. If the discharge is consistently less than 80% then
2000 cycles can be expected."

And on Page 12

"Once lithium batteries are fully
discharged, their voltage takes a
sudden nose-dive.
Completely discharging a lithium
battery bank, possibly even once,
may render your entire pack
permanently dead unless you have
added protection.
Inverters and chargers do not yet
come standard with profiles for
Lithium Batteries. Remember, this
is a new and evolving technology,
and not quite yet ready to be “plug
and go”.
There are several Lithium Battery
providers who can offer this.
The Kimberley in-battery controller
is one of these that provides
low voltage cut-out in each and
every battery and high discharge
protection as standard."

The EV-Power site suggests 2,000 cycles at 70% discharge but seems to contradict itself with:

"All lithium Ion batteries require a battery management system (BMS). There is no way around this. There are numerous examples of catastrophic failures where no BMS has been used.
At a minimum a BMS must have the following basic functions:
1) Balance the cells during charge to level the state of charge of all cells in the pack.
2) Protect each cell in the battery from going outside its safe voltage range."

AND

"The 12V series are actually 4 LFP cells in one package. They do not have any management. For systems of more than 12V nominal individual cell management is recommended."

EV Power recommended a Management System for my project, which will have a large LIPO4 battery in a camper. I am trying to learn as I go.

Keith
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FollowupID: 790014

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