Charging E bike batteries

[Skewif]

Skewif, thanks however I have 2 new 100ah leisure batteries and my bike battery is 378w and usually only requires a top up from say 50 per cent. Thanks for your help and I even did it myself

Tom

I'm with you. I can only say add some solar.. There is nothing quite like knowing you are riding on sunshine. Enjoy.

 

[DavidG]

Hello Tom, I need to find a solution to the same problem. Did you find a workable solution?

 

[Bramco]

Thanks to advice on this thread, I bought a Maplins 600w modified sinewave inverter and used Anderson Powerpole connectors and an inline fuse directly wired to the under seat leisure battery. The inverter is small and neat and I stow it under the drivers seat when not in use but it works fine and seemed to charge the battery as quickly as at home.

Damn - wish I'd thought of buying one on the Maplin sale. Got mine from fleabay for about £50 a chinese generic one. Hooked everything up as per the notes from Skewif and the same as you Tom Rae with the Anderson Powerpole connectors again bought on fleabay. Btw there's an online guide to using the Powerpole connectors which is really helpful -> http://bit.ly/2K4iqLu.

Did the High Peak trail last week and tried it out on the way home. Was almost recharged by the time I got back. I'll have to try it sometime with the solar to see what the Victron inverter says. Maybe tomorrow - Tissington trail tomorrow.

 

[DrJuanKerr]

I've just bought myself a brace of 600w Zero 9 electric scooters for "sh1ts & giggles".

The charger states the following:
Model: GJS150-5460200
INPUT: AC100-240v~ 50/60Hz Max 1.6A
OUTPUT: DC 54.6v - 2.0A

The battery shows: 48v 10.4Ah

I'm running a single 120W panel from @Roger Donoghue with the WRM15 controller. From reading a previous thread @Roger Donoghue states "from a 120 w Cali panel I'd expect around 6 amps"

Electrickery has never been a strong point of mine. It's a dark art as far as I'm concerned!

@Skewif has a similar powered eBike and says:

For what it's worth. I charge my 500w Bosch e-bike battery via a 300w inverter from the leisure batteries. I installed a trailing (fused) 35A socket to the battery under the seat then just connect the inverter when needed. Normally aim to do the charging when driving but also have 200w solar that will almost keep up with what's going into the bike battery in good weather. My charger also states 2A in but also never seen it draw much more than 200w ~1A @230V. To keep house batteries topped up if I'm not going to drive and it's not sunny I'll start the engine for 30mins after an hour or so of charging once the bulk of the charge has gone in.

1. Would a 300W inverter serve my purposes also?
2. Additionally I'm guessing I'd need a pure sinewave as opposed to a modified sinewave inverter.
3. A google search of "300w inverter" however returns a whole multitude of results and an insane range of prices. Ranging from £29 to £99!! Is there a specific one that would particularly suit my requirements that anyone would recommend please?

Thanks

 

[Roger Donoghue]

To use an inverter I'd suggest only when the engine is running. It will chomp through your batteries.

Not sure you need a sinewave inverter for simply battery charging duties. I'm no expert on inverters mind you.

Your 120w panel will help, for sure. But it won't keep up.

The charger mentioned is rated at 480w (240v x 2 amp) which is way more. Skewif states it runs a lot lower though (I'd expect this when it's topping off the bike battery, but during bulk charge I'd be disappointed not to see ti running at full tilt - it would double the charging time at 1amp).

To take some confusion out of this I'll explain something in basic terms.

We use watts to compare electrical draw on items because it doesn't matter if the voltages are different - it describes the same amount of power.

Your solar panel is 20v. It is rated at 120w. Watts divided by volts = amps. So 120w / 20v = 6....... 6Amps

A 240v charger, rated at 2 amps - just flip the formula round. 240v x 2 amps = 480Watts

You can reverse that just as easily. 480w mains charger / 240v = 2 Amps

So you can see it's easier to talk about watts when comparing things with different voltages.

I refer to amps when talking about my solar kits because it's easier to get right. Solar panels are rated in ideal conditions - bright direct optimal sun, in.... the cold.... which is rare! Panels lose voltage as they get hotter. So people ask me why they never see 120w on their Victron app and that is why. It's easier to tell you what you get from my experience. 6ish amps.

It also doesn't help that panels are thought of as 12v panels, but they are 18-20v. They need to be above the battery voltage to allow for heat voltage drop, and less than ideal light voltage drop.

This is where MPPT chargers come in. Normal cheap chargers , when receiving 20v, charging a 12v battery, ditch the excess voltage as heat. MPPT chargers turn that excess voltage into charging current (amps)

 

[Loz]

@DrJuanKerr
Some switchmode battery chargers need a pure sinewave inverter otherwise they can get damaged and overheat due to sharpe edges of the waveform from cheaper inverters, but you won't know this until the particular charger overheats and fails, so if you can always buy a pure sinewave inverter if you can. (safe for other things as well)

Also, it is inefficient to invert up to mains voltage only to take it back down for charging, see if you can find a 12v dc-dc charger for your scooters.

 

[DrJuanKerr]

@DrJuanKerr
Some switchmode battery chargers need a pure sinewave inverter otherwise they can get damaged and overheat due to sharpe edges of the waveform from cheaper inverters, but you won't know this until the particular charger overheats and fails, so if you can always buy a pure sinewave inverter if you can. (safe for other things as well)

Also, it is inefficient to invert up to mains voltage only to take it back down for charging, see if you can find a 12v dc-dc charger for your scooters.

@Loz, I'm not sure a DC-DC charger is what I want. Not fully knowing the functionality of one, I've undertaken a little research "Battery-To-Battery chargers (also commonly know as DC-DC chargers) allow you to charge an auxiliary / leisure battery from your alternator whilst driving" and "They simply work by taking current from the starter battery to supply the energy for the charger to charge and maintain a leisure battery so will not effect the vehicles electronics as this is no different than taking energy for vehicle lights and heating etc"

I'm looking for a methodology of charging the scooter batteries in instances when I've no hook-up/ off grid

 

[Roger Donoghue]

DC to DC chargers don't exist just for 12v to 12 battery charging applications.

A car laptop charger might take 12v from the cigar socket and step it up to 20v to charge your laptop. All in DC.

I always advise customers to try and find a DC solution for their needs before resorting to an inverter.

I've installed one, for a friend, so his wife can use her hair tongues. He has 3 batteries all in parallel with 180w of solar. He's still managed to flatten them

 

[Loz]

yes, dc-dc inverters come in all shapes and sizes, you are referring to one type that we are using with our leisure setups.

What I am talking about is a DC charger for your scooters just like we have for our e-bikes.
Our e-bike can have a mains charger or a 12V charger that plugs into the 12v outlet.

However, doing a quick search is not finding a 12V charger for the zero 9. So until zero 9 make one you may have to use an inverter but as said before, make sure the zero 9 mains charger is happy with a mobified sinewave other a pure is needed to be safe.

example of mains and 12v version of the e-bike charger.

 

[DrJuanKerr]

.... why is nothing I want to do ever easy

 

[Legin]

This is my set up. Pure sine wave Victron 500VA. Good quality. Its connected direct to the front battery via 50A anderson connector. I use it with or without the engine running. I have two solar panels which top things up.

 

[Loz]

Of course, if you're on hookup, you are laughing..

 

[DrJuanKerr]

@Loz are you suggesting the system @Legin has implemented will only work when he's on a hookup?

 

[Legin]

If you have hook up then you dont need an inverter. We use this set up about twice a week. Its out today in Manchester as it happens. Load is 375w but not continuous. Few hours run time then it gets to recharge by a combination of driving and Solar or more often just Solar. It draws on both batteries although connected to the front one. Used to run it on my X3 single although meaty battery.

 

[DrJuanKerr]

If you have hook up then you dont need an inverter.

I realise that. i'm looking for a solution for the many instances when I have no hook up but still want to charge the scooter batteries

 

[Legin]

I realise that. i'm looking for a solution for the many instances when I have no hook up but still want to charge the scooter batteries

I realised you realise. Keep it simple do the pure sine inverter , works for e bike, computer etc etc. Forget the efficiency arguments the versatility wins out if its not a continuous drain ie like your e bike battery charging. I charge mine also btw.

 

[DrJuanKerr]

@Loz I see the inefficiency but I'm struggling to find any DCC options. Even the manufacturer said "Use the supplied charger" which, as help, was as useful as a nipple on a gold fish!

+ Legin I'm inclined to go the inverter route. I just need to figure out which one to get amongst the multitude on offer! Any suggestions?
Cheers

 

[Skewif]

View attachment 56230
I've just bought myself a brace of 600w Zero 9 electric scooters for "sh1ts & giggles".

The charger states the following:
Model: GJS150-5460200
INPUT: AC100-240v~ 50/60Hz Max 1.6A
OUTPUT: DC 54.6v - 2.0A

The battery shows: 48v 10.4Ah

I'm running a single 120W panel from @Roger Donoghue with the WRM15 controller. From reading a previous thread @Roger Donoghue states "from a 120 w Cali panel I'd expect around 6 amps"

Electrickery has never been a strong point of mine. It's a dark art as far as I'm concerned!

@Skewif has a similar powered eBike and says:

1. Would a 300W inverter serve my purposes also?
2. Additionally I'm guessing I'd need a pure sinewave as opposed to a modified sinewave inverter.
3. A google search of "300w inverter" however returns a whole multitude of results and an insane range of prices. Ranging from £29 to £99!! Is there a specific one that would particularly suit my requirements that anyone would recommend please?

Thanks

Yes you can charge your bike battery using a 300w inverter without draining the house batteries too much. You say output of the charger is 54.6v + 2A so that's 110w. So the charger and inverter with say an 15% combined efficiency loss will be drawing about 9.7A + 13V. ((54.26x 2)/13)x1.15. If this is correct I take it the instructions say it takes 5 hours to charge a fully flat battery? The 1.6A max stated for the charger input will be the surge on plugging it in when using 110v so not a reliable measure. Even if there is a surge at plug in most inverters have a momentary power handling of 1.5 to 2 times their rating.
So (approximately) if both your bike batteries are + 50% its going to take 5 hours and 630w of energy to charge them. Your total house battery capacity is ~1900w but only ~950w is usable to keep the batteries above the safe 50% charge. So in (my) theory your house batteries will be at 65% after charging both half flat batteries if not using any other power and without any solar input. If your solar gives you an average of 4A per hour over the 5 hour charging time (260w) then only 370w will be used from house batteries leaving them at ~75% charged.

With a 300w inverter you could (if above assumptions are correct) charge both batteries at the same time but you would need the inverter hard wired to the house batteries as would need 20A+. This way if off grid you get more use of the bikes and could run the engine for 20/30 mins 2/3 through the charge cycle to keep house batteries near full. Combined with your solar and sun you could do this indefinitely off grid even with fridge and lights etc. If both bike batteries are empty I'd aim to charge them both when driving or on hook up if possible.

Get a pure sine wave inverter. A good one should last many decades (mine is 30 years old) so a small investment for all the uses. Some of the cheap ones are not pure. Best to check reviews on say youtube before you buy.

hope that helps

 

[DrJuanKerr]

hope that helps

"Hope that helps"?
@Skewif that is, quite frankly, Fricking awesome help. Thanks

Your assumption of instructions saying 5hr to charge is also correct

Next step ...... I need to source a good 300W sinewave inverter

 

[DrJuanKerr]

It's a minefield as far as inverters are concerned! I had no idea there was so much choice and variety.
@Skewif @Legin & @Loz what are your thoughts on this one? Bestek appear to have great reviews.
https://www.amazon.co.uk/dp/B076P9PGX3/?tag=vwcalifornia-21
It plugs into the cigarette lighter but I understand from a previous reply it would be best "hardwired" to the battery under the drivers seat.

Is this correct also?
A 20amp fuse [in addition to the internal one] would be wise to add. Ideally Anderson-type fittings would be a good idea also so the inverter can be detached and put away when not in use
Thanks

 

[Legin]

I would suggest a Victron pure sine inverter as they are good quality if your looking for a recommendation The 500 VA is what I use and this will give you some margin if you put a load on in future with a high start up current. Like a 199 you can use just 150 if you wish , same with the inverter. However it would appear a 375 VA is enough for your needs.

 

[Legin]

The bestek is an unknown qty as far as im concerned , get what you pay for. I suggest you wire direct front battery using the 50a anderson connector as my pic above. Once the seat is refitted you dont see it. I do indeed unplug it and store in the boot or under rear seat when not in use.

Suggest this

VICTRON PHOENIX BLUEPOWER 12V / 375VA-300W PURE SINEWAVE INVERTER PIN123750400 | eBay

Victron Energy Phoenix 12V 375VA-300W Inverter with VE.Direct. With the possibility of an Eco mode the Victron Phoenix Inverter will automatically switch to standby if the load decreases and gets lower than the pre-set value of 15w.

www.ebay.co.uk

 

[Loz]

It's a minefield as far as inverters are concerned! I had no idea there was so much choice and variety.
@Skewif @Legin & @Loz what are your thoughts on this one? Bestek appear to have great reviews.
https://www.amazon.co.uk/dp/B076P9PGX3/?tag=vwcalifornia-21
It plugs into the cigarette lighter but I understand from a previous reply it would be best "hardwired" to the battery under the drivers seat.

Is this correct also?
A 20amp fuse [in addition to the internal one] would be wise to add. Ideally Anderson-type fittings would be a good idea also so the inverter can be detached and put away when not in use
Thanks

I would not purchase ANY serious inverter of that size if it suggests that it can be plugged into a cigar lighter 12v socket.
A decent inverter will be hard-wired with good heavy gauge short cables and fused accordingly.
A major brand like Victron or Mastervolt etc. would be my choice also.

 

[DrJuanKerr]

One Victron Energy VE.Direct Phoenix Inverter 12/375 12V 375VA UK Plug - PIN123750400 bought and paid for.

Bought from here --> https://www.visionmarine.co.uk/victron-phoenix-sine-wave-inverter-12v-375w-with-uk-plug.html for the bargain price of £105.99 delivered
Thanks folks

 

[DrJuanKerr]

I've just received this from the scooter manufacturer
"Although we can not guarantee proper functionality while using an inverter, and are not liable for damage caused to the charger, scooter, inverter, or power source, I would recommend a pure sine wave inverter

An MSW inverter may work temporarily, but will generate more heat and possibly cause risk of fire or damage to the charger and scooter. The max draw from the ZERO charger is 330W.
We do not currently offer a DC to DC option, and I do not know of a working option at this time. I hope this helps"

As the Victron Energy I've just ordered is a pure sine inverter does it meet that full criteria? Again, thanks for the help and guidance