Battery Charger Question

[Alberta Mike]

My little 6V battery is out of my Road Toad for the winter, I keep it downstairs. Like other stored batteries for various things I have over the winter, I usually put a little charge into them every couple of months. I don't have a small amperage 6V charger for wet cell batteries but I have one here from an old Black & Decker lawn grass edger which I kept after tossing the edger years ago. The charger kicks out about 7 DC volts and has a very small amperage rating, something like maybe 0.2 amps. Can I use this to charge my Road Toad battery now and then over the winter? And yes I know I could probably hunt one down and buy it, but if I can use this one that'll mean I can buy the wife a Christmas present this year

Thanks for the replies.

[Makotosun]

I can’t answer your question on the B&D charger, but iuse the Schumacher float charger below. They run about $20 at Walmart and auto adjust for 12 or 6 volt batteries.

[Hydraulic Jack]

The answer is that you can use it, but don't leave it connected indefinitely.

Seven rated volts output probably translates to nine or ten in reality depending on load. All battery chargers make more voltage than the label rating, and all batteries need and hold more voltage than their "rating." A six volt battery with only 6 volts in it is a dead battery.

So try it and see. As for 0.2 amps, this might be a trickle if attached to a deep cycle marine battery, but for a tiny bike battery, it is a significant rate of charge. Again, what the unit is rated to produce, and what it really produces can easily be two different things, depending on load. NiCad batteries and lead acid batteries don't respond the same. Also, I doubt that a garden tool charger has a computer chip that regulates output in the same way a new automotive battery charger would. In other words, it is probably an old school "dumb" charger. It is up to you to monitor the battery during charge.

[viclioce]

I bought a nice one at Batteries Plus! Is similar to the Schumacher pictured earlier, and made by Noco. It can be switched between 6 volt & 12 volt. Trickle charging and battery maintaining available in both voltage modes. Lots of attachments, and one which can easily be cut and bullet connectors added to fit the Hodaka batteries. Here’s a pic! They are $32.99. I like that they can switch easily between 6 & 12 volts. Victor

[taber hodaka]

Battery's have a optimum temperature they store best at 77 degrees. they are affected by super cold and super hot. A fully charged 6 volt is 7.2 volts and a 12 volt battery is 14.2. A battery that you keep charged will function better and last longer than one you discharge allot. -----Clarence

[Alberta Mike]

Thanks for all the replies. I used this little charger, pretty low amperage, and it bought the voltage level up (see later on in this post). I think this battery I bought in July is on the fritz. It had sat for about 6-7 weeks until last week and even before that, the bike was driven very little. Not sure if the charge was ever really "up to snuff" from the start, I never did measure it with my multimeter. When I took the battery out for winter storage it only measured 3.7 volts which is a pretty serious discharged state. Why I started to wonder about all of this is that when I started the bike up to run some fuel stabilizer through it before storage last week, the electrical system didn't have enough juice to cause the turn signals to flash. All the lights worked and the signal lights glowed but didn't flash. Last summer after the new battery was installed the signal lights did flash. Anyways, last night the voltage was up to 6.15 volts on my workbench (after charging) but overnight (with the charger off) it had dropped down to 6.0 volts. I'm letting it sit today to see what happens over the next 24 hours. It shouldn't drop off like that I don't think without any load on it of any kind. If it keeps dropping, I'll phone the bike shop and see what they have to say. Any further comments from the Hodaka crowd are welcome as usual.

[Hydraulic Jack]

All lead acid batteries must be charged to full capacity before placing in service. This usually takes several hours to overnight depending on rate of charge, and whether you are using a tapering charge device. If you did not fully,charge the battery before using it in the bike, it was never "up to snuff" as you say, but not necessarily the battery's fault. You should also verify voltage at rest from time to time once in service, and if you are not going to ride your bike for a while, disconnect the battery. If the at rest voltage is found to be low, put it on a charger. Riding won't bring the voltage up to full capacity if the battery is discharged.

Leaving it sit at this point will show a decline in voltage. Put it back on a charger for another day and check again, watching the battery for signs of overcharge. You should see a slow bubbling from the acid, and it is best to take the water caps off the battery and just lay them back in place so they can vent. While the battery is vented, each cell vents through a shared passage which could be blocked, but usually won't vent well enough during charging.

Verify battery condition with a hygrometer, not a volt meter. The bolt meter will give you a preliminary sign of condition, but if the acid density varies more than one ball, 25%, between any two cells, the low cell is bad and the battery likely won't recover.

By the way, the at rest voltage of a 12v auto battery at full capacity is 12.7, not 14.2. Sorry Clarence. You would see 14.2 while it is charging, but once at rest, voltage will drop back down. Anything higher than 12.7 is temporary float voltage which will disappear as soon as any kind of load is applied. Also, full voltage for a 6V battery is 6.4, not 7.2 for the same reason.

[Alberta Mike]

OK Jack, I'll see what happens with that and report back in later after I see how far it will drop over the next day or so. So let's say I can coax it to 6.4 after that (which you say is full voltage), would you expect it to drop while in storage over time a bit without hooking up the charger? And if the answer is yes, what might it be expected to drop down to?

[taber hodaka]

Some times the memory fades glad you were there Jack. I would guess most people do not, or are not that familiar with the hydrometer?? You also use a temperature correction with it, if you are going to be exact. ------------Clarence

[Alberta Mike]

Clarence ..... I see the handle Taber Hodaka ..... as in Taber, Alberta (as in Taber corn, etc) ???

[Hydraulic Jack]

All batteries will lose voltage over time. Assuming your battery regains full potential, it should stay above 6 volts for a month. These old school batteries are not maintenance free by any means, and they don't last forever even when maintained reasonably. I don't think I have ever had one last more than three years.

If you can get 6.2 to 6.4 and get it to hold that voltage on the bench for a couple of days, I think you will be okay. For storage, disconnect it, keep it inside the house or at least well above freezing, and check voltage every few weeks.

Recently I replaced a 5 amp 12 volt battery in a vintage street bike with a battery from the hardware store that I bought out of curiosity. It was an SLA battery (sealed lead acid) intended for emergency lighting and other household purposes. It had nearly the same amp rating as the original style, same physical size more or less, but had blade connections, not screw posts. So I made some connectors to adapt to the bike harness.

Well, it is over a year old now, sat all winter in the back of a storage shed hooked up to the bike, totally ignored. This summer, after more than 6 months storage, I finally pulled out the bike and turned the key. The old battery would have been long ago dead sitting unattended all winter, but this new battery fired right up, ran the lights, and started the bike. It did need a charge of course, but was not dead at all. It had around 12.4 volts. Plus,when fully charged and at rest, it holds a slightly higher voltage, between 12.8 and 13.2.

So far all good, and it cost all of $12. There are a ton of SLA batteries out there. Find one that fits your battery box and has a similar amp rating. They are an impressive battery for a low price, don't weigh as much, and can be mounted in any orientation. And they don't leak. I have another similar battery that came out of a large HID handheld flashlight and has been dead for several years. It still has not leaked a bit. So they do eventually die just like any other battery, but while they are working, they work pretty well.