Charging ebike on the go with a portable power bank?

Hi -

Wondering If I could plug an electric bike into something like this for charging the ebike battery while on the go (eg, as a backup power reserve on a long trip)

https://www.amazon.com/Portable-Charger-RAVPower-20100mAh-External/dp/B00OZM8PEW/ref=asc_df_B00OZM8PEW/?tag=hyprod-20&linkCode=df0&hvadid=309812019776&hvpos=1o2&hvnetw=g&hvrand=2106640803797500681&hvpone=&hvptwo=&hvqmt=&hvdev=c&hvdvcmdl=&hvlocint=&hvlocphy=9007249&hvtargid=pla-593434626434&psc=1


If so, how would one calculate how long it would take to charge, and could a power supply like this cause any damage to the battery?
 

Mr. Coffee

Well-Known Member
Hi -

Wondering If I could plug an electric bike into something like this for charging the ebike battery while on the go (eg, as a backup power reserve on a long trip)

https://www.amazon.com/Portable-Charger-RAVPower-20100mAh-External/dp/B00OZM8PEW/ref=asc_df_B00OZM8PEW/?tag=hyprod-20&linkCode=df0&hvadid=309812019776&hvpos=1o2&hvnetw=g&hvrand=2106640803797500681&hvpone=&hvptwo=&hvqmt=&hvdev=c&hvdvcmdl=&hvlocint=&hvlocphy=9007249&hvtargid=pla-593434626434&psc=1


If so, how would one calculate how long it would take to charge, and could a power supply like this cause any damage to the battery?
That power pack only holds about 100wh, while most e-bike batteries are 500wh or more. So you wouldn't do yourself a whole lot of good.

You could haul one of these in a trailer and get yourself some real range...
 

Alaskan

Well-Known Member
That power pack is nothing more than a battery with standard outlets. You would be way better off buying a spare battery and carrying it along on your ride in a trunk bag.

As to using an inverter, you simply plug it in to the cigarette lighter/auxiliary 12v outlet in your car. It is best to pay a bit extra for a TRUE/PURE SINE WAVE inverter such at this to assure proper operation of your charger.
 

6zfshdb

Well-Known Member
How do you have it wired to your vehicle?
I have a heavy duty pickup with a plow package. It came with a factory installed 2500 watt inverter controlled by a dash switch. The unit I mentioned above would have to be wired separately.
 

J.R.

Well-Known Member
An inverter is a good option. Whether using an inverter or generator it should be 'pure sine wave' for charging lithium-ion battery packs.
 

Alex M

Active Member
Bikeman, you probably didn't read the specs. Even then, the size of this pack is 3 or 4 times smaller than 600 WH ebike battery, so how many watt hours it holds, what do you think?
This battery is 5V*20AH = 100 WH. Buy a spare ebike battery.
Charging it through inverter in a parked vehicle you will deplete your car battery very quickly, don't do this.
Charging in a moving vehicle involves some risk - you have to make 100% sure that it fixed reliably and won't fly off the seat. Li batteries don't like being tossed around, a short is a possibility.
 

PaD

Well-Known Member
I kind of like the idea of a spare tank. A spare battery for a Specialized Vado is $900. They only sell their largest battery, the 604Wh.
If I buy the Vado 5.0 I’m looking at I get a 604Wh battery with the bike and personally I would probably be ok with an extra 200Wh in some form.
The 400Wh battery that comes with Vado 1.0 is not for sale. ( and the same goes for the 460Wh and the 504Wh)
 

Mr. Coffee

Well-Known Member
I kind of like the idea of a spare tank. A spare battery for a Specialized Vado is $900. They only sell their largest battery, the 604Wh.
If I buy the Vado 5.0 I’m looking at I get a 604Wh battery with the bike and personally I would probably be ok with an extra 200Wh in some form.
The 400Wh battery that comes with Vado 1.0 is not for sale. ( and the same goes for the 460Wh and the 504Wh)
Except for the fact that the efficiency loss with one of those things is going to be more than painful. That 100wh is probably going to provide an effective 60wh-75wh of charging after you convert to AC and then back to DC at a different voltage to charge your bike battery. Even a DC-to-DC converter is probably going to have substantial efficiency losses.
 

PaD

Well-Known Member
Except for the fact that the efficiency loss with one of those things is going to be more than painful. That 100wh is probably going to provide an effective 60wh-75wh of charging after you convert to AC and then back to DC at a different voltage to charge your bike battery. Even a DC-to-DC converter is probably going to have substantial efficiency losses.
Yes the power banks in first post are not going to help much. It’s just that I like the idea of beeing able to bring a reasonably sized and not to expensive spare tank in some way.
A 700Wh capacity battery as on the Turbo Levo Carbon would be nice for the Vado. I probably wouldn’t need more.
 
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Nova Haibike

Well-Known Member
[QUOTE="PaD, post: 192718, member: 19895"It’s just that I like the idea of beeing able to bring a reasonably sized and not to expensive spare tank in some way.[/QUOTE]

Manufacturers could make smaller capacity batteries if the market was there. My Yamaha-powered bike only came with a 400wH battery, and sometimes I wish it came with the 500wH. A spare 500wH battery is about $900. Ouch. I'd probably be more incline to buy say a 200wH spare if it were both cheaper and smaller than either of the normal battery packs.
 

rich c

Well-Known Member
Carrying an extra, long down tube battery pack will not be nearly as convenient as the sizes that fit in a rack pack or pannier. New designs make them stealthier, but at the cost of impossible lengths to carry.
 

Nova Haibike

Well-Known Member
Carrying an extra, long down tube battery pack will not be nearly as convenient as the sizes that fit in a rack pack or pannier. New designs make them stealthier, but at the cost of impossible lengths to carry.
My external Yamaha pack is quite long; much longer than Bosch's battery. My idea for a smaller reserve pack: the cell body would make up the lower half, and a folding or telescoping armature would engage the locking portion when in use.
 

indianajo

Well-Known Member
I'm thinking buying a 2nd 840-960 wh battery for touring. Take two chargers. Ride 50 miles, change over at lunch, ride another 50 miles, my hips and hands would be done for the day. So would be the batteries. Check into a motel and charge them both up at night, bike stays cabled to a pole. (downstairs rooms cost more). Camping is not on the agenda, I did that professionally for USAR and that was enough of that. It is a cargo bike, a few bad weather clothes plus my standard repair/flat kit would leave room for a change of clothes etc. I could make eastern OH or TN in a coupla days.
 
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Alex M

Active Member
Yes the power banks in first post are not going to help much. It’s just that I like the idea of beeing able to bring a reasonably sized and not to expensive spare tank in some way.
Automotive 12V*100AH AGM, completely sealed, deep cycle battery costs $200 (for a decent brand) and holds 600-700 WH usable charge. 70 lbs weight is not an issue in a car, but you better charge it in a car, without carrying it around. Will need DC-DC converter though.
 

Ebiker01

Active Member
Automotive 12V*100AH AGM, completely sealed, deep cycle battery costs $200 (for a decent brand) and holds 600-700 WH usable charge. 70 lbs weight is not an issue in a car, but you better charge it in a car, without carrying it around. Will need DC-DC converter though.
With a bike trailer or should i say ebike trailer, since we have already ebike grips and so on...,one could put that car battery in it And securely run the cable to the ebike battery charging it on the go ?
What are possible wrongs/risks here ?
 

indianajo

Well-Known Member
With a bike trailer or should i say ebike trailer, since we have already ebike grips and so on...,one could put that car battery in it And securely run the cable to the ebike battery charging it on the go ?
What are possible wrongs/risks here ?
Too heavy, too much wind resistance, too much drag, and the wrong voltage requiring multiple devices to invert 12 vdc to AC and downconvert to lithium battery voltage again. More junk to carry around, inverter,AC charger for lithium battery,AC charger for lead acid battery. The whole purpose of lithium batteries is to make a product light enough to be used on bicycles. 23 extra pounds for a DD motor & long range battery is bad enough. Besides lead acid batteries, in the "maintenance free" variety, sulfate up and become useless if not exercised some large percentage of capacity several times a month. I'm hoping lithium ion batteries don't have the same syndrome.
 

Mr. Coffee

Well-Known Member
With a bike trailer or should i say ebike trailer, since we have already ebike grips and so on...,one could put that car battery in it And securely run the cable to the ebike battery charging it on the go ?
What are possible wrongs/risks here ?
Lead-acid batteries are more than twice as heavy for a given WH rating than lithium batteries.

You''d need more than the battery -- at a minimum you'd need a sinewave AC inverter and your e-bike charger. You could build custom circuitry to do that and I'd love to watch you try from a safe distance.

Lead-acid batteries are also less efficient with respect to charging and you should expect in general higher system losses with lead-acid batteries.

If you did go that route I'd recommend looking at marine or RV batteries as their designed use cycle would be closer to your requirements than a straight-up car battery.