In-situ car battery charging

On my Harley motorcycle I have a male/female 2 pin Molex plug. Ring terminals on the battery. 1.5 amp Schauer floating charge. Battery is going on 9 years old and I don't anticipate replacing it soon. You could rig something that is wired to the battery comes into the cabin where your other wires pass through from the engine compartment. You could then plug into that. Make sure you use a fuse on the positive wire at the battery connection.

--
Live Fast, Die Young and Leave a Pretty Corpse

I'd opt for one of those bulky battery connectors found in (APC) UPS's. No, you don't need that sort of current handling capability (unless you also wanted to use this as a power *outlet* to connect, for example, an inverter!). But, the connector is "ample" (in terms of size), keyed and easy to manhandle -- I suspect you are looking for something you can easily plug in without having to "fuss over it".

I suspect this would also fare reasonably well in rain/snow as they aren't "precision" components, it is not a "pin and socket" style connection (rather, two blades) that could fill with water and freeze, etc.

I'll see if I can find a URL of a suitable image...

The reply fom MP is generally the best method to approach the situation. You should use a suitable gage of wire to exceed the charging capacity and avoid any sharp metal in routing the wires.

The important part is the fuse near the battery terminal. The fuse capacity should exceed the charging capacity by about 150-200 %, if you intend to avoid using the charging connector for any other equipment. Having a method to cover the interior connector's terminals would be a good idea, to avoid any accidental contact between them, or contact with any other electrical potentials (car body metal, for example). I like using urethane vacuum caps for covering connector ends.. they're the type of soft caps that are used on fittings to block off a barbed fitting stem.

A stainless steel terminal would be most suitable if connecting directly to the battery connector, although you can probably find a full-time B+ junction block near the battery to add the terminal to.

-- Cheers, WB .............

(click on the 4th? "alternate view" to see this enlarged)

This is about 1.5" across -- to give you a sense of scale.

I suggest it mainly because I come across a *lot* of discarded UPS's and these connectors are among my favorite "pulls" (be sure to get both mating halves if you go this route!)

Note that the blades (contacts) are easily released from the connector shell so you can unsolder the existing wire and make a new connection, if desired. You can also slide the blades into some *other* shell (there are different variations of this same connector body theme)

Something like this then.

Widely available.

Jeff

The Schumacher 1.5 amp Battery Companion comes with the appropriate male/ female Molex connectors. But you'd have to lengthen the battery end wires. Must of these come with decent connectors designed to protect from shorts however none come with fuses. A fuse at the battery is a must. Prevents fires. A 5 amp fuse should do the job although the lower the better. My Icom 706MKIIG uses about 25 amps on HF and I have some stranded #8 running through the firewall. Positive is fused with a 25 amp fuse at the battery, the same value as the double fused factory cable. I've seen a van burn to the ground that was improperly fused and had some high power audio gear inside I don't want that to happen to me. Grommets through the firewall are a must also.

--
Live Fast, Die Young and Leave a Pretty Corpse

Rather than using a Molex plug system, I'd recommend using Anderson PowerPole connectors. They're designed to survive a large number of connect/disconnect cycles without wearing out.

Most of the amateur-radio emergency groups have moved to using these, rather than Molex, due to their ruggedness and their ability to create "universal" connection systems (e.g. any battery or power supply or device will connect to any other, with proper polarity and with no "gender changers" being required).

The 15-amp PowerPole connectors and inserts are probably what you'd want.

I agree, fusing the "hot" lead near the battery is a very good idea.

--
Dave Platt                                    AE6EO
Friends of Jade Warrior home page:  http://www.radagast.org/jade-warrior
  I do _not_ wish to receive unsolicited commercial email, and I will
     boycott any company which has the gall to send me such ads!

Per Dave Platt:

+1

--
PeteCresswell

Does anyone produce a bigger version of the "electric toothbrush" charger system? - inductively coupled. I've seen a system for charging multiple mobile phones etc using this. What is the minimum power transfer required and the minimum clearance between a sender on the floor and the receiver coil mounted under the car. ? Then no plugging in required at all

I hardly think the OP is going to find it tedious to plug in his charger. One thing he could do is to rewire his cigarette lighter to remain live with the ignition off. Then all he would need would be a lighter plug on the charger end. Personally I would just run some 18 ga through a grommet already established for engine to dash wiring, install a 5 amp fuse at the batter end and use a Molex plug or whatever plug comes with the float charger. They usually have a plug, mine did. And it is suitable for the interior of the cabin. I let mine lay all summer in between the passenger seat and center console. When the temperatures dip below 10F I use the charger. My vehicle has a self start feature. Just bump the key and release. If batter voltage is low because of the ambient temperature the start relay tends to release before the engine starts then re-engages the starter making it grind into the flywheel. Keeping the battery at top voltage prevents this. What I need is a better brand of battery not susceptible to cold or a heater in my garage :)

--
Live Fast, Die Young and Leave a Pretty Corpse

Thanks everyone for your inputs.

Meat Plow, I initially thought of rewiring the cigar lighter as you suggested, but could not identify the wiring to it. All the leads come out on the engine side of the bulkhead through a rubber gaiter. There are dozens of wires bound up in a tight bunch about 40mm in diameter. They leave the gaiter inside the fusebox and immediately disappear under the fuses. There is no way I can identify the one that feeds the cigar lighter. The user manual gives me the fuse number but that fuses several circuits. I’ve tried to get the wiring diagram from the internet but with no success.

Inside the car, the rear of the bulkhead is entirely covered in a unit of plastic panels that house instruments, heater, radio, glove pockets, airbags, etc, and which extend from the windscreen down to within

14” of the floor. It’s impossible to remove them to get at the wiring without know-how or special tools – neither of which I have.

So I have settled for fitting an alternative connector. I have located the source of a suitable 10A one and a 7.5A inline fuse. All I have to do now is find a route for the cable through the bulkhead! Not an easy job………!

--
pebe

snip

Can you find a hot fuse in the fuse panel with the ignition off?

tm

I sort of did it the other way round - fitted the battery charger in the car, and a waterproof mains inlet under the rear bumper. The charger itself is alongside the spare wheel under the boot floor so doesn't get in the way.

--
*Time flies like an arrow. Fruit flies like a banana.*

    Dave Plowman        dave@davenoise.co.uk           London SW
                  To e-mail, change noise into sound.

Yes there is.

I used to have a 6-volt car, and it was hard to start in the Chicago winter, so I put a one-amp battery charger inside the engine compartment, with its 12 volt cord still wrapped up like new and the alligator clips on the battery posts, and I put the AC cord through the grill.

Whenever I got home, I plugged it in to an extension cord that I ran from the kitchen and hung on a pole. I did that all winter, rain and shine, never took the extension cord inside. Even when it snowed and the middle of the wire was underneath the snow, everything was fine. Never blew a fuse. (I didn't handle the plug or outlet directly when it was wet. I either had on gloves or I pulled it apart by the wires.)

I wan't sure the 6-volt setting was really enough to keep it charged, so I set it on the 12-volt setting, and the circuit breaker would trip ever 90 seconds and reset 20 seconds after that. And that caused no problem either about 720 cycles a day for 100 days or more, 72000 cycles, and still working fine when spring came.

The circuit breaker was a little clear glass thing with a point with a little knob on the end, that looks something like a neon bulb or one of the small xmas tree lights.

And the car started all winter too, except new years eve, very very cold, when the tow truck couldn't start it either. I guess I hitched a ride that night.

BTW, this was 1967 to '68 and the car was a '50 Olds V8 303ci engine. I sold the car but I still have the charger and, after replacing the diodes in 1980, it still works fine. The charger belonged to my cousin (as did the car) and was about 10 years old in 1968, so it's about 52 years old, but looks quite modern and in v. good condition.

In Alaska and northern States, it is common to have a "pig tail" type of connector accessible from the exterior where mains ac can be connected for overnight, or day-over back-up charging for below-zero temperature seasons. This amounts to a short wire extension off the + and - battery terminals to a compatible male or female connector accessible on the exterior, such as feeding it out through radiator air louvers by a headlight or over a bumper. It may need to be wrapped to prevent enrooted water and road grit from entering. Presumably, you will have an attending mating plug from a mains-supplied DC charging source where you park or store your car.

My experience in battery life and maintenance (driving since 1944) is that a battery starts service in good condition, can survive a few extremes of abuse such as light-on drain to nil PROVIDED it is charged back full slowly or "by the book". My greatest battery life achieved that way was nine years (my wife's '63 Chevy stick shift, no A/C). These days, I seem to get about five years life from a four-year guarantee battery.

Your concern deals with midlife where the battery has uncertain good life remaining. and trickle charging as you propose will give you more months of successful cold weather starting. But remember, a lead-acid and any other storage battery is like us... it never get any younger nor any better than when first new.

There always comes a time when it is prudent that the battery be replaced. My gage of that event is when it has failed for the second time to start when I want it to. After the first failure, I do a slow and humane recharge, sometimes leaving it connected to trickle charge (less than 2 amps), for two or three days in a row. A "second chance" failure after little elapsed time of normal driving is clear evidence of being permanently degraded (sulphated, bent separators and plates, or accumulated bits of either at the cell bottom shorting adjacent plates).

I usually resurrect that battery once more, while simultaneously looking for a replacement source, either on the internet or at a nearby battery service center. This second resurrection is used only to drive to that service center while avoiding a tow charge or an embarrassing hunt for a "jump start".

Angelo Campanella

The latest post makes me want to add: a) I doubt I'll ever get past 9 years. I just about make it to the warranty limit most times.

b) Besides having a good battery my recommendation for not getting stuck is eiither a Battery Buddy, if you can find one on ebay or somewhere, or a Battery Brain, which I've never had but seems to be the logical successor to Battery Buddy.

Both disconnect the battery when its charge or voltage gets low, leaving enough to start the car. I just have to open the hood and push a big red button on the box that I strapped to the battery.

Because of assorted extra current drains, or disconnecting the headlight buzzer and leaving the lights, and not getting a replacement battery when I maybe I should have, my Battery Buddy has saved me 100 or 200 times over the last 20 years, only failing to work once about 6 months ago, but it's worked since then 5 or 10 times. I have another one I bought last year in case this one fails, but I'm not ready to change it yet.

It also says it won't turn the battery off when the 4-way flasher is flashing. No experience with that. My battery always goes dead in the middle of the night.

The Battery Brain is about 60 or 65 dollars, twice the Buddy, but I'll buy one when the second buddy breaks. I've only been stuck once in

20 years.

I also have to reset the presets on the car radio, and the time, and the engine control computer forgets what it has learned about how my car runs, so sometimes it takes two consecutive tries to start the car, but the car seems back to normal after only 10 seconds or so. (Maybe not?)

Don't forget the strain relief on both ends so it will disconnect itself without "drama" when you back out of the garage without disconnecting the plug.

Smart move... Most larger vehicles (trucks) have a seven pin flat blade connector that includes a battery pin. This pin can be used to charge the battery, and if you disable the locking tab on the connector (not the receptical) you can make it self disconnecting just like on the space shuttle launches!