This winter I'd like to try to keep my batteries in good condition if
possible. I've got a zero turn mower, tractor, truck, backhoe, marine
batteries for the boat, I've counted 8 lead acid batteries to maintain in
all. My goal is to keep everything charged to be ready when I need it and
have my batteries to still be good next year when I need to mow again.
Possibilities are on-board automatic chargers or perhaps use weatherproof
connectors and running cables to a cabinet with chargers. Not sure if I
should run 120V to each vehicle for an on board charger or run the chargers
in a cabinet and run 12V charge leads to each battery. Just wondering if
any here have recommendations or good/bad experiences with such?
That would be great on the mower. I occasionally use the 4WD truck and the
tractor with front end loader during the winter but a freezing engine seems
to take a good charge to get running. I like the idea of sealed automatic
marine chargers myself but they seem to be on the expensive side. That is
probably the main reason I'm considering an enclosure for chargers and
running cords for the charging. I'm hoping extended leads will work OK with
low current maintenance charging.
My SOP on winter machine that are a bit old:
Hook up engine block heater wait 30 minutes
Hook up large charger, set to 40 amp.
Put in starting ether.
Hit glow plug heater.
Starts right up even at -40.
Now, i did have an old car that wouldn't start at -50 with this treatment.
So, I lifted car with floor jack and stuck the 500,000 BTU knipco under. 20
minutes later i was on my way.
Sounds like your SOP ought to work well. My truck has a block heater, I'm
not sure if it's on all the time it's plugged in or if it has a thermostat.
Most days I take my ~ 35MPG car and only take a truck if I need to haul
something or it's bad weather needing the 4X4 (sometimes not even once a
year). Usually the problem is that I wake up and find out if I need the
truck or not. The last time that happened, the truck didn't have enough
charge in the batteries to get it started, I plugged in the block heater and
the charger, got it started a couple hours later. This year I hope to
improve the situation by keeping the batteries charged and turning on the
block heater if snow/ice is in the forecast.
Friend's big White Field Boss generally didn't need to be started in
the winter - had the blower on a smaller tractor - but after a big
storm sometimes he'd need the boss - or if the hydro went out he's
hook the "boss" to the Winco.
To start it cold, he'd pull the air intake off and lay a Bernzomatic
torch in the manifold for a few minutes, then crank it over, and away
it would go, every time. Sure saved running the glow plugs and
wearing the battery down. When the hydro's off you don't have the
option of the block heater or the battery charger.
On Sun, 11 Oct 2009 17:23:36 -0500, "Karl Townsend"
Guy I used to work with in the late sixties had a 60 Corvair that
lived in a corn-crib for the winter - and he drove it to work every
morning. HIS sop was get out of bed, turn on the coffee, go out and
pull the steel fence stake wrapped in burlap and chichen wire out of
the barrel of used oil and deisel fuel, shoot a bit of ether at it,
light it and stick it under the back of the Corvair.
Go in, drink the coffee, eat brakfast, come out and start the Corvair
to go to work.
The back end of that beast was a mess of black oily soot, but he never
missed a day of work.
Never burned the darn thing either. Never could figure THAT one out.
For your 4WD you might want to look into the small solar panels that sit on
the dash board, and plug into the lighter socket to trickle charge the
For your loader, getting a block heater and removing the battery to the
garage might be a good idea. Also I presume the loader has a diesel engine,
so some winter fuel treatment to keep the fuel from gelling might be a good
If you are not part of the solution, you are not dissolved in the solvent.
None personally, but I met a merchant marine sailor that kept a car in
storage while he was at sea and used one of these and he seemed to be
pleased that he could start his car and go after leaving it for months at a
Seems to me it might be worth a shot for the OP to try as draping wires all
over the place or lugging batteries in and out of vehicles in the freezing
cold can't be fun.
About the time I had mastered getting the toothpaste back in the tube, then
\How cold does it get at your location?
\How many sunny days do you have at your location?
I'm not far from St Louis, it's warmer than Chicago but it's not unusual to
get a few 4WD snow days a year. That's the problem I had last year, my 1
ton 4WD truck doesn't get driven much unless I have to haul something or
need the 4WD. We had a snow day and I needed to take the truck and had to
charge the trucks (F350 diesel with 2 batteries) for a couple of hours
before it would start. This year I'm wanting to keep the truck ready to go
plus try to keep the seasonal batteries in shape for next year. I already
have a few bad batteries but I'd like to have automatic charging working
before buying new batteries. The backhoe is handy year around but only
using it every couple of months keeps the batteries dying.
/Okay...much more adverse environment than we have here in southern CA.
/Anything that NEEDS to run during the winter should have a trickle
/charger and engine heater.
/Anything else you can charge on a regular basis...just keep the charge
/topped off or the batteries will freeze.
/Be careful enclosing any charger...they do need ventilaton. I came
/very close to burning a van up by closing the hood on the van with a
/charger inside...I caught it as it was smoking.
/It is better to run a 110v extension cord than to run long 12v
/lines...low voltage lines drop too much voltage and give the charger
/an errorous indication as to its charge.
/A comment on trickle chargers...I have had several batteries killed by
/chargers that overcharged the batteries.
/Also in my experience smart chargers are not so smart...I have seen
/them not charge batteries or overcharge them....always watch them.
I've also been disappointed with some of the smart chargers and that is at
least part of the reason for my post here, thought maybe someone here found
one to recommend. I'm not sure I understand the difficulty a "Smart"
charger would have with batteries. Seems my auto voltage regulators keep my
batteries happy for years on the car I drive daily. So, maybe if I had a
charger that automatically started charging when the power was on, I could
set a time to charge the battery for maybe an hour a day, to simulate
driving the car an hour a day.
/Smart chargers are based on a chip that have the lead acid charge/
/decay curves telling it how to act. I suspect it monitors the voltage
/of the battery and if that info is faulty then the charger works
/I too am a believer in settng chargers up on a timer.
/How long to charge? Good question. I just do it a hour a day with 2
/amp chargers and it seems to work. YMMV
That gives me an idea, if I use a 2 amp charger that starts when connected,
wired the output through relays and use a spare PLC, I can use one charger
and automatically switch it to each battery for 1 hour a day. I can
separate the long runs and run 120VAC to an on board charger.
An alternative to 2 Amps for 1 hour per day is 80mA all the time,
although 25mA - 50mA might be enough. You can make a constant-current
source with a few transistor/resistor/diode parts powered by a 16-20V
wall-wart. Some circuit variations are shown in following refs. For
fixed font, click More Options, Show original.
High side, PNP (eg 2N3906), w LED voltage ref and indicator. Choose R1
between 100 ohms and 100K ohms so that LED brightness is adequate and there's
at least 100 uA (microamps) to spare to drive the base of the transistor.
Choose R2 = Rs = sense resistor to satisfy Rs * Im + Vbe = Vled, where
Im = desired current, Vbe = typical Vbe drop ~ .7V, Vled = LED voltage ~
1.6V. Eg, for 50mA, Rs * .05 + .7 = 1.6 --> Rs = 18 ohms. Attach battery
to be charged between "Out" and ground. With supply voltage Vs and charge
voltage Vx, there will be Vs - Vx volts across R2 and Q1; eg, if Vs , Rs,
Vbe=1.6, Im=.05, and Vx.6, then V(R2) = 18*.05 = .9V, so Vce -0.9-13.6
=5.5V. So 275mW is dissipated in transistor with Vs = 20V; it would be
better to use Vs = 16V, giving Vce=1.5V and power = 75mW.
Low side, NPN, w LED. Use 2N2222, 2N3904, or similar. If supply voltage Vs
is fixed and reasonably stiff, one can also use a resistive divider: Put
R2 = 100K in place of the 150 ohm resistor and R1 = 5K-9K in place of the
LED. Eg, with Vs VDC, R1=5.6K, and max current = Im = 60mA, sense resistor
Rs = 4.7 ohm = ((Vs*R1/(R1+R2))-Vbe)/Im. One can also put a 5K trimpot in
place of R1, to make the constant current adjustable from 0mA up to about
40mA. However, with a 10K pot, max current would be about 210mA (which is
over the 200mA absolute maximum rating of 2N2222 and 2N3904 transistors)
unless you increase R2 to say 102K. :)
Low side, NPN, as drawn uses one transistor and one resistor per additional
CCS. Advantages of diode voltage-ref over resistor divider ref: Temperature
compensation, if diode and transistor junction temps are the same; and
less dependence on exact value of Vs.
The 2A rating on a lead acid battery charger is more like 2A for a
discharged battery and lower current depending on the state of charge, quite
different than a 2A constant current charger. So, with what I was thinking
if the battery needed the charge, it would draw up to 2A from the charger,
if not, it might only draw a fraction of an amp from the charger to keep
itself in a good state of charge.
From what I read today, a daily charge voltage should be from 14.2V to 14.4V
at 20 Deg. C with a -0.022V per Deg. C temperature coefficient. I have some
PLC's around with RTD and thermocouple inputs plus analog inputs and
outputs. I guess to ultimate solution would be to measure the temperature,
calculate the perfect charge voltage, and apply it to a daily charge
routine. I'm more likely to just switch my Schumacher 6A/2A charger to each
battery for an hour a day and call it good enough. At least it would be
better than no charge at all until I need to use the vehicle.
I have thought of using a diy circuit, perhaps similar to what you are
thinking of. I was thinking of using an adjustable voltage regulator with a
resistor inline to lower the voltage output as the current increased. I
played with a circuit simulator and found a resistors that would give good
current at 12V and decrease to near zero around 14.4V.
The "2A" range on my 2/10/50A Schumacher starts at 4 - 5A and
decreases as the battery comes up; it passed smoothly through 2A but
didn't stay there, IIRC at cutoff the current was less than 1A.
An LM317 adjustable regulator IC is enough to make a decent trickle
charger. Adjust the pot that sets it to the end voltage, the device
limits the current to 1.25A max, then it falls off as the battery
nears the set point. You could print the temperature compensation
chart and tape it to the box.
This is a commercial version with voltage and current meters:
The one-turn voltage adjustment is tricky but good enough for lead-
acids, though you'll need a separate voltmeter with more resolution
/The "2A" range on my 2/10/50A Schumacher starts at 4 - 5A and
/decreases as the battery comes up; it passed smoothly through 2A but
/didn't stay there, IIRC at cutoff the current was less than 1A.
/An LM317 adjustable regulator IC is enough to make a decent trickle
/charger. Adjust the pot that sets it to the end voltage, the device
/limits the current to 1.25A max, then it falls off as the battery
/nears the set point. You could print the temperature compensation
/chart and tape it to the box.
/This is a commercial version with voltage and current meters:
/The one-turn voltage adjustment is tricky but good enough for lead-
/acids, though you'll need a separate voltmeter with more resolution
That would be interesting, I could send a higher DC voltage to the vehicle
and have the voltage regulator on board. It would be neat if I could get
temperature compensation close with a PT100 RTD or similar, I guess I'd just
have to calculate the temperature coefficient of the platinum
versus -0.022V/deg C for the battery. Anyway, if I could get the circuit
right, I could power it a couple of hours a day and keep the battery topped
off. I would think that would do at least as good as an automotive
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