brucedp5 wrote:

> 12VDC deep-cycle batteries do not last as long as 6V golf/traction
> batteries. The latter have thicker plates= more lead.

The latter part of this statement is no longer necessarily true; as the golf 
industry moved to 12V floodeds for their 48V cars, 12V flooded batteries became 
available that have the same plates as their 6V (and 8V) brethren (e.g. Trojan 
T1275 and US12VXC models).

> The Zivan k & ng series chargers evolved into the series Elcon sells.

This is incorrect; the Chinese-origin PFC chargers that Elcon sells began as 
clones of the Delta-Q charger and evolved from there.  It is a bit confusing 
because Elcon was previously representing the Zivan product line, and so some 
mistakenly associate the Elcon-branded PFC chargers with Zivan.

Note that the Elcon-branded PFC chargers will not have *any* regulatory 
approvals; any "CE" mark on them, if examined closely, will be found not to be 
the European (self-declaration, not 3rd-party inspected) regulatory mark, but a 
remarkably similar marking of no related meaning that is specific to China.  
This is one reason that the Delta-Q products are somewhat more expensive; 
internally they use approved insulation systems, etc. and are tested to comply 
with North American (and European and various other locale's) EMI, EMC, and 
safety agency standards.

> The advantage is both of these charger brands are dual input voltage (they
> run off either 120 or 240VAC). Which means, Mary could continue to charge
> off a 120VAC outlet as she had in the past, but at some point she could
> buy an upgrade j1772 kit from an EV component re-seller (there are a few
> on the evdl) that would allow Mary to charge her MG EV off the 240VAC a
> public EVSE would provide.

Agreed; this is a definite reason to upgrade to a more modern, universal input 
charger model.

Note that "dual voltage" chargers are probably best avoided, as this usually 
implies a (non-PFC) charger whose input automatically switches between a "120V" 
and "240V" setting based on the input line voltage, or one that must be 
manually switched between settings the by the user each time they plug into a 
different voltage source.

Public (J1772 level 2) charging stations will be either 208V aor 240V, while an 
overnight charge at home will usually be from a 120V outlet; it could be fatal 
to a dual input charger if one forgot to switch it to the appropriate input 
voltage range before plugging in.

> An alternative to the alternative ...
> Way in the past, an evdl member poo-poo's my use of several individual
> 12VDC chargers to charge my pack. Stating that it increases the probability
> of a charger failure. Later, other EVrs installed individual 12V chargers
> and had good success (so poo-poo to the poo-poo'r).
> 
> 12VDC chargers found on ebay are incredibility cheap (almost those away if
> they fail, cheap).

I won't poo-poo the idea, but I don't recommend the use of multiple chargers 
spanning a pack unless there really is no viable alternative.  Aside from the 
reliability issue, the reality is that all commonly available 'fuel'/Ah/SOC 
gauges look only at overall pack voltage and overall pack current, and so can 
only ever account for the charge current/Ah of *one* of the N chargers spanning 
the pack.

What invariably happens is that each charger delivers somewhat different 
current, and so unless one waits until *every* charger has completed, they will 
drive off with each section of their pack at a different SOC, and will only 
know the SOC of the single section that the gauge was monitoring the current 
for.  The worst case is that one of the chargers fails (fuse opens, or wiring 
fault, or simply derates thermally because it is in a hot location, etc.) and 
the user discovers this only when that section of the pack runs flat (or 
reverses...) while they are driving.

> I would order 8 of the 10A US models. The outputs would go across each
> battery (one 10 12V charger for battery), and all the AC plugs would be
> wired into one line, so you only have to plug in one 102VAC cord (same as
> before).

Be careful here: it is quite easy to end up with a bank of chargers whose input 
power requirements exceed what a common outlet can provide.  At 2.4V/cell and 
10A, each of these chargers would be outputting 144W; 1152W for 8 of them.  
They might only be 80% efficient, which brings the input power up to 1440W.  
This is right at the 12A that a 15A-rated 120V circuit can provide *IF* the 
voltage at the charger input is 120V.  Usually, the outlet voltage is lower, 
and so the current drawn by the chargers will be higher.  If they are not PFC, 
then the peak input current will be even higher than that estimated just by the 
power requirements.

A bank of 8 of these ~might~ just squeak by on a 15A 120V circuit, but a 20A 
120V circuit is probably a better choice.  Opportunity charging on a 15A 
circuit would definitely be risky without knowing what else might be on the 
same breaker.

2 such banks would only be feasible with each running from its own 120V 
circuit, or both running from a 240V circuit - if they support universal input.

If one were to go the multiple charger route, I would suggest buying at least a 
few spares, and I would suggest that it is essential to mount them such that 
one can easily see the status of *all* chargers in a single location.

Cheers,

Roger.

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