[RE-wrenches] bad battery = system overvoltage = dead inverter

[Randy Brooks]

Has anyone tried using a battery management system (BMS) like those used on electric vehicle battery banks?  Here is an example:
http://www.manzanitamicro.com/products?page=shop.product_details&flypage=flypage.tpl&product_id=87&category_id=22

Randy Brooks
Brooks Solar, Inc.
Solar Power for People
140 Columbia View
Chelan, WA  98816
509-682-9646
Randy at BrooksSolar.com
www.BrooksSolar.com

On Mar 15, 2013, at 8:05 PM, Dan Fink <danbob88 at gmail.com> wrote:

> This has been happening all too frequently here. We live in a big area
> of off grid homes, dozens of systems.
> Lost a customers Trace 2624 this morning; One L-16 in older 24v bank
> opened internally. PV array/MPPT control zorched inverter as soon as
> the sun came up. First indication of problems last nite when customer
> hit microwave to warm up dinner and inverter went crazy. This morning
> the bad battery showed 3.2v (yes, I would expect 2 or 4 also) the rest
> the usual 6+v. Turned on PV array, bad battery immediately up to 11v
> (yes, 6v L16).
> 
> Somebody needs to build a "battery condom" with big stacked diodes on
> a big heat sink or some such solution. A voltage brick wall for system
> charging inputs. MPPT PV controllers do NOT protect a inverter from
> input overvoltage if all or part of the battery bank disappears! And
> last year we saw a nice battery box fire and zorched inverters due to
> similar -- dual 48v L16 strings, one cell failed and opened, other
> string dumped everything into the bad one, smoke and flames. Parallel
> fusing would have stopped that......but not stopped the loss of dual
> stacked XW inverters from PV overvoltage.
> 
> Or am I missing something here?
> 
> Dan Fink,
> Executive Director;
> Otherpower
> Buckville Energy Consulting
> Buckville Publications LLC
> NABCEP / IREC accredited Continuing Education Providers
> 970.672.4342
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