Battery Tender Amperage?

Forgive me: I'm an electrical numbskull.

So, my understanding of Amperage is that it is affected by how much a device attached to the charger actually demands. So, if my device demands 1 Amp, a charger rated for 30 Amps would be okay to use since the device will still only draw 1 Amp.

However, I'm not sure that a battery tender relies on a demand for power since the battery is largely at rest.

So, what would be the difference in using a .75Amp tender versus a 5Amp tender?



I want to plug a battery tender directly into my Powerlet jack in lieu of pulling the battery every Winter.

The last time I hooked my battery tender up this way, it blew the in-line 30A fuse to my Powerlet.

EASt said:

I want to plug a battery tender directly into my Powerlet jack in lieu of pulling the battery every Winter.

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Is there perhaps a middle course? My Battery Tender came with an SAE connector and a mating pigtail; I wired the pigtail with one half of the plug straight to the battery, and connect the plug from the Tender lead into the plug on the pigtail. Easy-peasy. Never need to pull the battery as long as your storage location has electricity to power the Tender, which it sounds like yours does.

ibike2havefun said:

Is there perhaps a middle course? My Battery Tender came with an SAE connector and a mating pigtail; I wired the pigtail with one half of the plug straight to the battery, and connect the plug from the Tender lead into the plug on the pigtail. Easy-peasy. Never need to pull the battery as long as your storage location has electricity to power the Tender, which it sounds like yours does.

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Hmmm. This is making me think of a photo I saw once where police departments were putting a lead from the positive terminal of the battery to a bolt which was screwed through the underside of the rear seat so they could hook a jump starter to them.

Ideally, I'd like to do as little rewiring as possible, and have as few connectors going to my battery as possible. Does that pigtail you wired dangle in the bike year round?

EASt said:

Does that pigtail you wired dangle in the bike year round?

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Except that I keep it tucked in behind the frame, yes. The connector has a cap that keeps the terminals out of the weather and away from contact with the frame.

I try to ride at least once a month over the winters so I have not pulled the battery in the past two years, even though my storage site does not have an electrical power source for me to keep the Tender connected. During the summer, when the bike is parked in my driveway, I keep the Tender on it between rides. (I also keep the bike under a cover; although it's not waterproof, it helps keep "casual" moisture at bay or at least that's what I tell myself.)

Your idea to use the Powerlet receptacle should have worked. Are you sure the matching Powerlet plug on the tender was wired correctly? It sounds like you shorted something in the outlet. I'm pretty sure the battery tender wouldn't have the amperage to blow a 30 Amp fuse. Check the label on the tender for output amperage.

Ride Safe
John

Aren't the Battery Tenders suppose to check for correct polarity before they apply power?

I have used my Powerlet connector exactly as you are trying to do. My Battery Tender is only a 2 amp charger though.

Sent from my SM-G935V using Tapatalk

EASt said:

So, my understanding of Amperage is that it is affected by how much a device attached to the charger actually demands. So, if my device demands 1 Amp, a charger rated for 30 Amps would be okay to use since the device will still only draw 1 Amp.

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Not exactly. Current depends on voltage and resistance. If you have a 12-volt power supply and a load that has a resistance of 12Ω, Ohm's law (Current = Voltage / Resistance) says the current will be 1A.

Batteries aren't loads. They have very low internal resistance, enough so that for all intents and purposes, a large battery is a dead short when seen from the outside. If you connect a charger that's capable of delivering 30A, it will have no idea whether the battery can handle that kind of current and will deliver all of it because there's not enough resistance to slow it down. The battery will have lots of current flowing through it, making heat, boiling the electrolyte and doing other damage to the internal parts. (It'll also burp out a lot of very flammable hydrogen gas in the process.)

This is why you can't use a 12V power supply to charge a battery. Chargers have to be current-limiting, which means they have circuitry in them that adjusts the voltage to keep the amount of current flowing down to something that isn't going to destroy the battery. The rule of thumb for batteries is that charge current should be limited to about 10% of capacity, so a 14 AH battery should be charged at no more than 1.4A.

So, what would be the difference in using a .75Amp tender versus a 5Amp tender?

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If you're using an honest-to-god Deltran Battery Tender or something that understands how to safely charge a battery, nothing other than the .75A model taking longer to bring the battery up to a full charge. If you're using something else, see the comment above about boiling electrolyte, frogs, locusts and death of first-born batteries.

I want to plug a battery tender directly into my Powerlet jack in lieu of pulling the battery every Winter. The last time I hooked my battery tender up this way, it blew the in-line 30A fuse to my Powerlet.

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First things first: You should not be fusing your Powerlets at 30A. Pull that fuse out of there and don't install another one until you've figured out the right size. (I'll be more than happy to help you figure out what that is.) Powerlets are only rated to carry 16A, and unless you've put in very large wire, that fuse isn't going to prevent the socket or the wiring from melting down and possibly starting a fire in the event of a short.

Whatever you connected was either a dead short from the battery's perspective or was able to deliver loads of current and did so until the fuse blew. Sounds like the wrong thing in either case, and you were fortunate that the current was enough to blow the fuse. If it wasn't, things would have become very messy very quickly.

As long as your Powerlet is on a properly-fused, un-switched circuit and connect it to the right battery charger for the job, charging through it should be no problem. My ST has charged that way for at least a decade.

--Mark

Blrfl said:

The rule of thumb for batteries is that charge current should be limited to about 10% of capacity, so a 14 AH battery should be charged at no more than 1.4A.

If you're using an honest-to-god Deltran Battery Tender or something that understands how to safely charge a battery, nothing other than the .75A model taking longer to bring the battery up to a full charge. If you're using something else, see the comment above about boiling electrolyte, frogs, locusts and death of first-born batteries.

Powerlets are only rated to carry 16A, and unless you've put in very large wire, that fuse isn't going to prevent the socket or the wiring from melting down and possibly starting a fire in the event of a short.

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I think this strikes to the issue I had.

I never knew that Powerlets were limited to 16A. I don't have anything that draws that much, but still, this is good to know.

I'm hearing that a lower amperage battery tender (.75A) would take longer to bring the battery to charge, but I'm also hearing that the lower the amperage, the safer the battery tender will be, overall. So, for long-term, winter storage, where I'm not necessarily re-charging, but simply letting the tender maintain the charge, .75 Amps is more than enough to work with.

EASt said:

.75 Amps is more than enough to work with.

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The Battery Tender's Power Tender (5A) looks like what I should have. I want something that will revive a reluctant battery should I go out the the bike one day and it doesn't start. I've used the Tender Jr. and it just takes too long to bring the battery up. My two car battery charges are too bulky to use especially if I'm in something of a hurry. Obviously the state of the battery at that time will affect time-to-starting. But I have hill to roll down and won't be bump starting the beaST on level ground.

5A is outside the 10% recommendation Mark mentioned but when ya gotta go ya gotta go. I'd guess bump or jump starting puts the charging rate over 5A at some point. And it does shift to tender mode.

I got one of the dual powerlet socket kits. The instructions list a 15A fuse. I don't know what the sockets themselves are rated for. Wired for heated gear they should work fine for a Tender. Then I'd consider replacing the regular 7.5A SAE Tender pigtail with something more studly for true jumpstarting.

I'm beginning to get a better handle on electrics now, but I'm still fully capable of burning my motorcycle to the ground if left unsupervised.

I think I'll go with a battery tender in the range of .75 - 1.25 Amps. I'm thinking purely for winter storage.

Blrfl said:

My ST has charged that way for at least a decade.

--Mark

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Must be one heck of a battery to take that long to reach full charge. (Sorry, Mark - I couldn't resist taking that out of context.)

ST Gui said:

The Battery Tender's Power Tender (5A) looks like what I should have. I want something that will revive a reluctant battery should I go out the the bike one day and it doesn't start. I've used the Tender Jr. and it just takes too long to bring the battery up. My two car battery charges are too bulky to use especially if I'm in something of a hurry. Obviously the state of the battery at that time will affect time-to-starting. But I have hill to roll down and won't be bump starting the beaST on level ground.

5A is outside the 10% recommendation Mark mentioned but when ya gotta go ya gotta go. I'd guess bump or jump starting puts the charging rate over 5A at some point. And it does shift to tender mode.

I got one of the dual powerlet socket kits. The instructions list a 15A fuse. I don't know what the sockets themselves are rated for. Wired for heated gear they should work fine for a Tender. Then I'd consider replacing the regular 7.5A SAE Tender pigtail with something more studly for true jumpstarting.

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I'm confused. What B Tender pigtail are you talking about? If you want to jump start the bike, you cannot do it with small gauge wire. You can charge the battery up with said 5 amp charger and the factory pigtail but it will take some time. I don't know of any SAE connector that will handle enough juice to jump start the bike.

Your generator gives at least 28A ( old 1100). The battery takes what it needs to charge.
As long as your charging voltage is not over 14,5 V ( for a limited time, several hours, like riding the bike), don't worry.
For long time charging, on a tender, don't go over 13,8V ( this is the voltage where a battery starts gassing. I. G Losing electrolyte. ).
Just connect the tende for a few hours every week.
That's more than sufficient.
Just to compensate for clocks/alarms/ECU..
Btw I never use a tender.
My ST runs at least 6 days a week. Mostly commuting.
(145.000 km in 4 years...).
Winters? In Holland? [emoji6][emoji1093]

Take your pick of sizes. The 45 to 75 amp connectors would work for a bike jump start. 10 ga would be minimum if a short length, 6 ga would be better.

https://powerwerx.com/anderson-power-powerpole-sb-connectors. scroll down to see all the options

I use the 50 amp SB connector with 8 ga wire since it is one piece connector ....

https://powerwerx.com/anderson-sb-connectors-sb50-50amp

If you go back to the main page and under wire and cables you can have them make the pig tail for you with a environmental cap.......

Mr Spiderman, could you please elaborate on how to construct a jump starting connection?

I made a fused 10 ga (I think) pigtail just like the Deltran one, and a matching SAE piece with a couple lugs on the end for jumping. Have never used it though.

QUOTE=DeanR;2016935]Mr Spiderman, could you please elaborate on how to construct a jump starting connection?

I made a fused 10 ga (I think) pigtail just like the Deltran one, and a matching SAE piece with a couple lugs on the end for jumping. Have never used it though.[/QUOTE]

Ok, for jump starting, you will need one mated pair of the second anderson powerpole connectors. As I understand their system, the conectors are identical and mate via a dovetailed slot so that you can push the two halves together in the dark (aka with your eyes closed) and they fit together only one way. The connection is made inside the plastic housing, so there are no exposed conductors or lugs (unlike an SAE connector which has one metal barrel exposed).

Take a short piece of #6 wire and crimp it to one of the anderson connectors. Crimp an eye on the other end. The eye will be bolted to your battery. Do the same for the other lead. Carefully insert the connector into the Anderson housing - I would use red for the Positive lead, black for the Neg lead. This portion of the setup will reside on your bike under the seat.

Now make up the other half. One end of your jumper cables will have the mating connector for the anderson system and the other end an alligator clip to go to your donor's battery (car, or bike). You make up two of these, one should be red, the other black. Use electrical tape or paint to id the wires, and insert the anderson connector into the housing in such a way that your red jumper will mate with the red (positive) lead from your bike's battery. Repeat for the negative lead. Double check your assembly - red alligator clip mates through the Anderson connector to your positive battery termial, black to your negative terminal.

Now, when you want to jump the bike, clip your red alligator clip to the donor positive battery, connect the two halves of the Anderson connector, and then clip the last black lead to the donor negative terminal. Your face should be away from the battery in case of sparking and/or explosions. It has been said before here not to have the donor vehicle's engine running while jumping the bike. Simply use the battery. I don't know why - but I guess the charging voltage from the donor vehicle might be too high for the electronics in your bike.

The fine print: For my money, I would use #6 welding cable, available at a good electrical supply house. Welding cable is very flexible due to many fine strands of copper wire - this is unlike common building wire - THHN/THWN insulation which may have only 22 strands. The welding wire is easier to handle but might be comparatively expensive. I used this stuff when I made a new ground strap for an old Guzzi.... Crimping anything larger than #10 wire into a lug will probably require a special crimper. You might get away with a hammer, steel punch, and a vise, but you will have to be careful and the chance of damaging the crimp connector are good. Decide how long you want the cables to be before you head out to buy the materials, and price the wire and alligator clips from several sources. Cheaper is not always better.

Very carefully.... NO fuse, but just like the Deltran one but heavier wire and bigger connector. Route the connector to be hidden under the pillion seat.

add mating bigger connector to standard jumper cables.....



added cover

SMSW said:

If you want to jump start the bike, you cannot do it with small gauge wire.

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You're not telling me anything I don't know.

DeanR said:

I made a fused 10 ga (I think) pigtail just like the Deltran one, and a matching SAE piece with a couple lugs on the end for jumping. Have never used it though.

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Don't bother unless it's a last resort and/or you've got time on your hands. 10ga cable will probably handle more current than an SAE connector. I'd avoid that for true jumpstarting. If you're going to use another bike's alternator to to 'tickle' your battery and you've to a time SAEs would be ok. I did that once for a friend's dead battery but let my bike idle fast for about 20m.

I recently tried that again with my DEAD battery and after 10min got nothing. A pair of very heavy duty jumper cables 3min and my buddy's BMW alternator on a moderately high idle and it fired right up. I'm sure I could have started his ignition Off but I didn't want to put any extra load his battery.

Like spidey says don't fuse jumper cables. You'd only blow most fuses and for true jumpstarting the cables should be heavy enough that they don't need protection (a fuse) to handle the load.

spidey— thanks for the lead on connectors.

ST Gui said:

5A is outside the 10% recommendation Mark mentioned but when ya gotta go ya gotta go. I'd guess bump or jump starting puts the charging rate over 5A at some point.

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Sure, but the average jump start is short enough that the battery can dissipate whatever heat it generates. Think of it as controlled abuse. The 10% figure is for continuous charging and is low enough that the battery isn't going to end up with more heat than it can get rid of.

SMSW said:

Must be one heck of a battery to take that long to reach full charge. (Sorry, Mark - I couldn't resist taking that out of context.)

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At the rate I've been out to ride in the last year, that might be just about right.

--Mark

Blrfl said:

Sure, but the average jump start is short enough that the battery can dissipate whatever heat it generates.

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That was my point. 5A is nothing when you consider what the alternator will do with a bump/jump start until the battery is charged.