Subject: [TR] Battery trickle charger

From: Angelo Graham <[email-masked]>
Date: Mon, 28 Jan 2013 19:53:02 -0500

Hello List:
My "el cheapo" 750 mA battery charger just bit the dust. Second one in a 
few years to fail. Purchased them from our local/national auto supply 
store (Canadian Tire).
Just wondering if there is a more reliable alternative available in the 
750 mA range to keep the battery alive through the winter storage 
period. This winter I have left the battery in the car with the trickle 
charger connected. Maybe I should remove it and take it inside?
Thanks for any leads or brand names.
Angelo Graham

** [email-masked] **

Archive: http://www.team.net/archive

---

From: [email-masked]
Date: Tue, 29 Jan 2013 01:55:04 +0000 (UTC)

I got Schumacher brand 1.5 amp "float" tenders at Walmart. Less than 20 bucks. Keep one on the Stag all the time.  No trouble.  

Phil Ethier West Side Saint Paul Minnesota USA
1973 Triumph Stag LE22439UBW "uncle jack", Sapphire Blue
2004 Suburban 8.1, Sport Red, the only automatic of the bunch
2005 Lotus Elise, Bordeaux Red Pearl
2007 Saturn Ion 3 2.4, Berry Red
[email-masked]
http://www.flickr.com/photos/pethier
http://www.flickr.com/groups/triumphtransamerica
http://www.mnautox.com
http://www.mntriumphs.org

---

From: "Wbeech" <[email-masked]>
Date: Mon, 28 Jan 2013 20:42:49 -0600

I have one from Harbor Freight, about 7 years old now, never a problem.
Probably paid $10 for it.
Bill 

-----Original Message-----
From: [email-masked]
[mailto:[email-masked]] On Behalf Of [email-masked]
Sent: Monday, January 28, 2013 7:55 PM
To: Alex&Janet Thomson
Cc: [email-masked]
Subject: Re: [TR] Battery trickle charger

I got Schumacher brand 1.5 amp "float" tenders at Walmart. Less than 20
bucks. Keep one on the Stag all the time.  No trouble.  

Archive: http://www.team.net/archive
http://autox.team.net/mailman/options/triumphs/[email-masked]

---

From: "Randall" <[email-masked]>
Date: Mon, 28 Jan 2013 21:58:06 -0800

> Probably paid $10 for it.

And they're frequently on sale for even less.  But don't hook them up to a
battery that is deeply discharged or has a shorted cell.  I burned up 3 of
them that way.  The only current limit seems to be the winding resistance in
the transformer.  When I tried replacing it with a stouter transformer, the
plastic box with the regulator melted before the regulator burned up.

This one is more money, but should be more rugged and probably even better
for your battery:
http://goo.gl/hNXpI

-- Randall

---

From: "Randall" <[email-masked]>
Date: Tue, 29 Jan 2013 06:21:15 -0800

> I replaced a 12 volt battery in my RV (for towing the 
> Spitfire race car) with two six volt batteries (to get more 
> amp hours/storage) wired in series to get 12 volts. Question 
> is do I charge it with a 6 volt or  12 volt charger? Maybe 12 
> if I hook the charger to where the pos and neg cables attach.

My choice would be to leave them connected in series and use a smart 12v
charger.  Lots less hassle than trying to charge each one individually and
equally; or reconnecting in parallel (so you can charge both at once at 6v).
There may be some advantage to using two 6v chargers (which would allow
leaving the batteries connected in series), but not enough to worry about
IMO.

As a side note, my old Winnebago had an AC charger built into the motorhome,
such that it would charge the 'camping' batteries when the coach was plugged
in.  But it was a 'dumb' charger and I blamed it for shortening the battery
life.  Likely the newer ones are better, but if you leave it plugged in for
long periods of time, you might want to look into that.  And if your RV
already has a smart charger, maybe just use that.

-- Randall

---

From: [email-masked]
Date: Tue, 29 Jan 2013 09:45:35 -0500 (EST)

Presuming that the two batteries are evenly loaded, and that means you 
don't have any 6 volt loads that will deplete the charge on one battery faster 
then on the other, you will be just fine with a 12 volt charger.  Just 
connect the positive lead to where the car's wiring hooks up and the negative to 
chassis.  The only connection to the other two terminals is the jumper cable 
between them.

Sure it would be better to have two six volt chargers but where do you get 
those?  They are available but for much more $$$. In a perfect world you 
would use 6 chargers, one for each cell - provided you had access to the 
terminals.  But that is way over the top.

Dave

In a message dated 1/29/2013 2:14:37 AM Central Standard Time, 
[email-masked] writes: 
> I replaced a 12 volt battery in my RV (for towing the Spitfire race  
> car) with two six volt batteries (to get more amp hours/storage) wired  
> in series to get 12 volts. Question is do I charge it with a 6 volt  
> or  12 volt charger? Maybe 12 if I hook the charger to where the pos  
> and neg cables attach.

---

From: [email-masked]
Date: Tue, 29 Jan 2013 10:06:01 -0500 (EST)

Actually, saying it is extremely important is a bit of hyperbole, 
especially in a cranking application where the level of discharge is not very deep.  
More important if you will be discharging deeply as in a wheel chair, 
electric vehicle situation or a situation where you are powering accessories when 
the engine is not running.  Since this is an RV the last might be the case.  
(Of course, if that is the case I suggest two 12 volt batteries with an 
isolator so that only one battery is used to power the devices saving the other 
to start the engine regardless.  I also recommend a deep discharge model 
for the battery powering the accessories and a cranking battery for starting.) 
 What IS important is to load the batteries equally.  That means NO! 6V 
loads that draw off only one battery.

I agree that two 12 volt batteries would probably be a better option.  
MGB's were originally equipped with two six volt batteries but many owners have 
converted to two 12 volt batteries in parallel.  Or just one 12 volt 
battery.

Lead acid batteries are pretty robust and tolerate the occasional 
overcharge without too much detriment so a one time charge upon initial installation 
where the two batteries are not charged to an equal state will be fine 
provided one isn't completely dead.

Dave

In a message dated 1/29/2013 5:02:36 AM Central Standard Time, 
[email-masked] writes: 
> When using two sixes in series, it's extremely important to have 
> identically
> sized batteries so they charge evenly from the regular vehicle charging
> system. When using a plug in charger, you can use the 6V setting and do 
> each
> one individually or set it to 12V and charge them as a single unit ( which
> is what your alternator is doing anyways). Since every battery is made of
> groups of 2V cells, you are really charging 6 cells in series on a single
> battery, 12V system. When charging the batteries individually, you should
> monitor battery voltage or specific gravity (if you can open the cells) so
> as to balance the degree of charge in each battery.
> 
> I have had better luck with using a pair of 12V batteries in parallel for
> added amperage capability on tractors. In fact, I converted two of my
> row-crop Deeres to this type of a setup from the original factory
> two-sixes-in-series system. They seem to last longer and big 6V batteries
> get pretty expensive. A group 4 6V is about $160 from a Deere dealer while
> group 31 12V (950 CCA) is about 100 bucks from a truck shop. But, that's
> getting away from your question.
> 
> Charging your batteries individually at 6V and using a voltmeter for the
> first time will probably show you if the batteries are balanced. If they
> are, after that you could use the 12V setting and charge them as a single
> unit. I assume the vehicle is  negative ground. In that case, black,
> negative charger cable to the chassis and red, positive cable to the 
> starter
> insulated circuit.