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Charge Controllers and Clippers => The "Classic" charge controller => Classic and Classic Lite BETA Firmware... => Topic started by: ClassicCrazy on October 26, 2016, 12:48:37 PM

Title: Firmware update for Lithium in the works ?
Post by: ClassicCrazy on October 26, 2016, 12:48:37 PM
Ryan or others ,
It was mentioned in the past that a future firmware update might have the ability to shut off charging from the classic if the battery temperature got below a certain point. This is important for lithiums since they are not supposed to be charged below freezing.

Are there any firmware updates  with this feature on the horizon or should I start relocating my lithium batteries for the winter ?

Thanks,
Larry
Title: Re: Firmware update for Lithium in the works ?
Post by: Westbranch on October 26, 2016, 03:44:10 PM
Larry, where is the site that will drop below freezing?

Reason I ask is that I think the issue is going to be that the charge will not start as the bank is already below freezing vs the temp dropping after a charge has started.
I am assuming that the cells are inside an insulated space and thus will warm up upon being charged, and that release of energy keeps the cells a bit warmer. 
Additionally the cycle will occur daily, keeping them warmer than the exposed environs.

Both my AGM banks, in the basement,  have shown this when being charged and starting at ~ -2* C and warm to +2 or so on a bright Sunny cold ( - 15* C) day...
Title: Re: Firmware update for Lithium in the works ?
Post by: ClassicCrazy on October 26, 2016, 06:08:06 PM
Right now my batteries are out in a shed which has been above freezing since spring - now coming into winter as the weather cools off - I need to build an insulated box for them , but they could still drop below freezing - if that happens it would be nice to take the charge off them. I may try to use an aux contact to turn some kind of heater on in the insulated box when extra power is available - maybe heat tape or something like that. But haven't gotten around to that yet.

I wish I had a basement to put them in !

Title: Re: Firmware update for Lithium in the works ?
Post by: Westbranch on October 26, 2016, 06:16:55 PM
have you looked into the logs to see just how cold they got last year? 
Those should be in the memory still...
Title: Re: Firmware update for Lithium in the works ?
Post by: ClassicCrazy on October 26, 2016, 07:48:01 PM
No - just put them into service this spring .
Title: Re: Firmware update for Lithium in the works ?
Post by: Westbranch on October 26, 2016, 08:17:43 PM
how cold did the L 16's get?

Add: just looking at the CALB 2.5 and 5 Kwh modules, they both have the same spec sheet, and only seem to accept about 700W incoming  and max 1000W and  low amps (30)  at that.
Title: Re: Firmware update for Lithium in the works ?
Post by: ClassicCrazy on October 26, 2016, 08:27:08 PM
I guess I could look up that data - but I know they would freeze - gets well below zero F ( -17 C)   in winter - or used to in the old days .
Title: Re: Firmware update for Lithium in the works ?
Post by: mike90045 on October 27, 2016, 03:23:50 AM
Don't LFP's have low resistance/impedance and therefor very low self-heating when charging (till something goes wrong)

So, simply put the Classic under the battery bank, and that will keep the batteries warm
Title: Re: Firmware update for Lithium in the works ?
Post by: ClassicCrazy on October 27, 2016, 10:52:12 AM
Quote from: mike90045 on October 27, 2016, 03:23:50 AM
Don't LFP's have low resistance/impedance and therefor very low self-heating when charging (till something goes wrong)

So, simply put the Classic under the battery bank, and that will keep the batteries warm

Interesting idea Mike - use the inefficiencies of the Classic to heat the battery space. But you would still have to super insulate the space to make it stay warm all night and on cloudy days. Plus design a nice tight container but have it accessible to get at the Classic. I can see why you would not want to do this with lead acid batteries since you wouldn't want to have all  your electronics in with acid off gas. But Lithiums no gas . But then you would have to design a venting system to remove extra heat . Sounds a bit complicated.

I would be better off to start digging a big hole in the ground. Although around here this summer and fall it has to be a water proof hole with all the rains we have had.

Larry
Title: Re: Firmware update for Lithium in the works ?
Post by: tecnodave on January 21, 2017, 12:18:24 AM
Larry,

Do you have a source of cocoa bean hulls?  Kinda off the wall but this stuff decomposes so hot that you will not pick up a 5 gallon milk tin of it decomposing.....we Alaskans use it for heat in the battery sheds. It's locally available from Giradelli Chocolate in Oakland CA. and other chocolatiers. I use about 300 pounds yearly in my remote cabin in Alaska to keep battery bank buried underground from freezing.

David
Title: Re: Firmware update for Lithium in the works ?
Post by: ClassicCrazy on January 21, 2017, 01:31:46 PM
Quote from: tecnodave on January 21, 2017, 12:18:24 AM
Larry,

Do you have a source of cocoa bean hulls?  Kinda off the wall but this stuff decomposes so hot that you will not pick up a 5 gallon milk tin of it decomposing.....we Alaskans use it for heat in the battery sheds. It's locally available from Giradelli Chocolate in Oakland CA. and other chocolatiers. I use about 300 pounds yearly in my remote cabin in Alaska to keep battery bank buried underground from freezing.

David

ha ha - no cocoa bean hulls around here ! 
I will just have to wait for warmer weather this winter- working on moving them inside for next year. In the mean time I have some new lead crystal gel cells which have very good performance in the cold compared to flooded lead acid.
Larry
Title: Re: Firmware update for Lithium in the works ?
Post by: David on July 31, 2017, 08:06:07 PM
Is there any news on this?  My bank would also potentially get below freezing and would prefer not to have to purchase additional hardware when the Classic could have a LiFePO4 temp mode that disable temp compensation for charge voltage but refuses to charge if sensor reads 32F or less.
Title: Re: Firmware update for Lithium in the works ?
Post by: ClassicCrazy on August 01, 2017, 11:31:16 AM
Quote from: David on July 31, 2017, 08:06:07 PM
Is there any news on this?  My bank would also potentially get below freezing and would prefer not to have to purchase additional hardware when the Classic could have a LiFePO4 temp mode that disable temp compensation for charge voltage but refuses to charge if sensor reads 32F or less.
Probably worth making a direct inquiry to Midnite to find out if anything is going to be happening with that.
Larry