Inverter/ebike battery charging

C

Chod Jacqui

Joined
Jul 20, 2019
Posts
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Location
Stourbridge
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62,547
MH
Le Voyageur LVX855 A
Exp
Since 2001
We have two Kalkhof ebikes, one charger is
Input 230v50Hz 2.0A max
Output 42v 4.0A
and the other
Input115/230v50/60Hz 3A/1.5A
Output 36v 4A/1A
What minimum size pure sine wave inverter should I use when not on hook up?
Also when is it best to charge, whilst driving, sun shining and powering solar panel or doesn't it matter?
Thank your for replies.
 
This thread may be of use
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Sizing an inverter

I’m looking at fitting a Pure sine wave inverter to charge eBike battery. the question is what size? Space is a premium….so it needs to be compact. ive two Bosch 230v chargers available , *one is a ‘standard‘ slow charge with a transformer with an input of 100-240v at 1.6A, output at 36V at 2A...
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Also have 2 Kalkhoff s. Depending on where we are and if connected to EHC usually use this method. Have also charged whilst on the move usually one battery at a time. I believe my inverter is 600 watts. Hope this helps
 
I have a cheapo MachineMart 600w inverter hard wired right next to the leisure batteries. It only gets used for charging the Kalkhoff ebike batteries (one at a time) and then, only while driving. The inverter cooling fan seems to cycle on and off plenty which was a bit disconcerting at first, but so far, no problems. A more expensive pure sine wave unit would most likely be a better option ?
 
Just bought a 600watt pure sinewave from the show to fit myself. Not had chance to use it yet. Just wondered how long does it take to charge one battery. Falcon were doing some offers but wanted £450 to fit one but also mentioned we would need a better regulater.

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We have 2 bosch 400 watt e bike batteries to charge
220 amps of electric when fully charged
120 watts of solar
Dont use more than 60 per cent of bike battery
Charging one a time 3-4 hours and not enough capacity to charge the other.
Having a rethink and will up solar and another battery over winter.
Charges so much better whilst driving

Currently we charge one on one day then the other on the next day, but it works for us, but not perfect
 
suavecarve said:
We have 2 bosch 400 watt e bike batteries to charge
220 amps of electric when fully charged
120 watts of solar
Dont use more than 60 per cent of bike battery
Charging one a time 3-4 hours and not enough capacity to charge the other.
Having a rethink and will up solar and another battery over winter.
Charges so much better whilst driving

Currently we charge one on one day then the other on the next day, but it works for us, but not perfect
Click to expand...
I'm struggling to see how 220A at 12v (let's say 110A of usable battery power) can't charge a 60% of a 400W e bike battery.
110A @ 12v = 1320W, 60% of 400w =240w
There should be plenty of juice available

The time to recharge I can believe though.
Our bosch battery is 650w. The standard charger is 36v @2A, so 72 W /H put back into the battery. If we were 60% (390W) depleted, that would take 5 1/2 hrs to recharge.

I've got a fast charger that is 6A@36v (so 216W/h), so that should see a recharge of a 60% depleted 650W battery in <2 hrs*

* in theory!
 
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We use the little and often method. We have a 1000 W inverter and charge each Bosch battery in turn. When the battery has depleted by 10% or so we let it recharge by solar before starting again. It takes a bit of organisation but all the batteries seem happy.
We have a Victron battery monitor which makes the calculations easier. It also depends how you use the bikes, you’ll struggle to recharge them from empty.
 
gerry mcg said:
I'm struggling to see how 220A at 12v (let's say 110A of usable battery power) can't charge a 60% of a 400W e bike battery.
110A @ 12v = 1320W, 60% of 400w =240w
There should be plenty of juice available

The time to recharge I can believe though.
Our bosch battery is 650w. The standard charger is 36v @2A, so 72 W /H put back into the battery. If we were 60% (390W) depleted, that would take 5 1/2 hrs to recharge.

I've got a fast charger that is 6A@36v (so 216W/h), so that should see a recharge of a 60% depleted 650W battery in <2 hrs*

* in theory!
Click to expand...
Youre right, it does do one of the 2 batteries but not quite both batteries before the bleeper goes off warning that there will be no tv tonight !
 
2x 500wh Bosch batteries (Kalkhoff bikes)
Chargers
1x 2A
1x 4A
Inverter Serling pure sine wave 300 Watts

Habitation batteries 2x100Ah lithium
275watts solar
45 amp victron alternator to battery booster

This set up charges both batteries simultaneously off hookup, with no bleating from the inverter.
Sustainable offgrid from April onwards with our cycling use approx 35 miles a day, charging every other day
Jon

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We have 2 x 400 watt bosch batteries, have a 1000 watt pure sine inverter, 3 x 78 ah gel batteries and 300 Watts of solar.
Although I can charge both batteries at once it hammers the batteries and even at this time of year will take a couple of days or more to recharge the leisure batteries.
To charge one bike battery from flat takes 30 amps for 2½ hours. Best to charge one at a time and top them up rather than let them go flat.
 
We have 1500 inverter with two sockets and top up charge rather than let them go flat. Mostly we are off grid so do this when travelling. Been doing this for 6 months of the year for last 7 years until covid, never a problem
 
Lenny HB said:
We have 2 x 400 watt bosch batteries, have a 1000 watt pure sine inverter, 3 x 78 ah gel batteries and 300 Watts of solar.
Although I can charge both batteries at once it hammers the batteries and even at this time of year will take a couple of days or more to recharge the leisure batteries.
To charge one bike battery from flat takes 30 amps for 2½ hours. Best to charge one at a time and top them up rather than let them go flat.
Click to expand...
Are you really putting 30Amps into an ebike battery? I thought most supplied chargers are 4Amps, not usually recommended to go above 8Amp.

Edit. Perhaps you are referring to the current being drawn by the inverter.
 
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I think Lenny HB meant 30Ah capacity drained from the hab battery bank equivalent of (I.e 400W /12V = 33Ah?)

I've probably got my higher physics terminology wrong!! But I get what he is saying, I.e the inverter is drawing something like 1.6A at 110-230v, and out putting at 36V at between 2A (for a bosch slow charger) to 6A for the bosch rapid charger
 
Last edited:
68c said:
Are you really putting 30Amps into an ebike battery? I thought most supplied chargers are 4Amps, not usually recommended to go above 8Amp.

Edit. Perhaps you are referring to the current being drawn by the inverter.
Click to expand...

gerry mcg said:
I think @Lenny HB meant 30Ah capacity drained from the hab battery bank equivalent of (I.e 400W /12V = 33Ah?)
Click to expand...
Yep, that's the current taken from the hab batteries when a single 400watt bosch battery is being charged via an inverter.

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Chod said:
We have two Kalkhof ebikes, one charger is
Input 230v50Hz 2.0A max
Output 42v 4.0A
and the other
Input115/230v50/60Hz 3A/1.5A
Output 36v 4A/1A
What minimum size pure sine wave inverter should I use when not on hook up?
Also when is it best to charge, whilst driving, sun shining and powering solar panel or doesn't it matter?
Thank your for replies.
Click to expand...
You can get 12 volt Bosch battery chargers but they are quite expensive
 
Unfortunately both our Bosch batteries have a different charging connection.
 
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Charging an electric bike when off grid

I’m a newbie and I apologise if this has been asked before but can you charge two electric bikes when you are off grid or should we always plan to be on hookup to charge them? I have a 150 W solar panel, one leisure battery and no inverter at the moment. As far as I can understand from my...
www.motorhomefun.co.uk www.motorhomefun.co.uk

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suavecarve said:
www.motorhomefun.co.uk

Charging an electric bike when off grid

I’m a newbie and I apologise if this has been asked before but can you charge two electric bikes when you are off grid or should we always plan to be on hookup to charge them? I have a 150 W solar panel, one leisure battery and no inverter at the moment. As far as I can understand from my...
www.motorhomefun.co.uk www.motorhomefun.co.uk
Click to expand...
Of course, its another eBike thread, I did see this....Thank you so much for sharing, I hope my funster friend (y) has picked up on this offer from eBay..
 

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