[RE-wrenches] Older iCel System Lithium Ion Batteries (Steve Higgins)

[Ray]

We found the Quick Charge Chargers to be the best deal for 48 v 
chargers, otherwise the Iota is good for lower voltages

https://quickcharge.com/

Ray Walters

Remote Solar


On 2/16/18 4:04 PM, Gary Rochlin wrote:
> Hi Tom;
>
> Each battery consists of 7 pack of 16 Panasonic CGR 1865D batteries making
> up a 48V system from what I understand from Panasonic 1.5 kWh.  The
> Panasonic tech mentioned he knew of the firm and gave me the name of one if
> the tech officers.  I'm going to look him up and see if I can get some info
> from him.  Going to purchase a 48V charger and test each battery to see if
> it hold a charge.  Thank you for your input.
>
>
> Gary Rochlin / Managing Partner
> Blue Sky Energy
> g.rochlin at blue-sky-energy.com
> 310.422.2908
>
>
>
> -----Original Message-----
> From: RE-wrenches [mailto:re-wrenches-bounces at lists.re-wrenches.org] On
> Behalf Of Tom Ruscitti
> Sent: Saturday, February 10, 2018 12:16 PM
> To: re-wrenches at lists.re-wrenches.org
> Subject: Re: [RE-wrenches] Older iCel System Lithium Ion Batteries (Steve
> Higgins)
>
> Some of my non-solar consulting involves test engineering for lithium ion
> materials development. I'm no expert but I do get to work with folks
> developing and testing cells and sit in on industry training and conferences
> now and then. I would discourage trying the jump start described here
> without direct guidance from the cell / battery manufacturer and a properly
> operating BMS. Li-ion batteries can be much less tolerant to over-charge and
> over-discharge than the lead acid we're used to working with in the solar
> business. Li-ion batteries require a strictly enforced minimum cutoff
> voltage. For example, the discharge cutoff for one recent client's battery
> is spec'd at 2.5V per cell. There can be damage to the anode If voltage
> falls below that. Also, if you try the jump-start on compromised packs with
> no BMS, different cells will charge at different rates due to differing
> internal resistance (one function of BMS is cell balancing). Over-charging
> can result in permanent capacity loss and also electrode damage. Depending
> on the chemistry this sort of damage can increase the risk of thermal
> events.
> I've heard that some BMS will prevent recharging if the minimum cell voltage
> limit has been busted, but no first hand experience myself. If you do a web
> search on "lithium ion damage over discharge" you'll see plenty of
> discussion. I tried to find specs on the iCel system but didn't find
> anything useful.
>
> be careful,
>
> Tom
>
> --
> Tom Ruscitti
> Senior Engineer
>
> Taitem Engineering, PC
> 110 S. Albany Street, Ithaca, NY 14850
> Mobile: (607) 220-7022
> www.taitem.com
>
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