Charging an electric bike.

We would need to know the battery capacity. Is there an Ah rating or kWh rating?

Are you reading that information from the battery or the battery charger.

That’s all true enough when spec’ing an inverter. But what I was looking to find out is what is the ebike’s battery capacity, as written on the battery. It’s important to know that your habitation battery capacity will be capable of replacing the bikes discharged capacity on a regular basis without leaving you high and dry.

Ok, I wasn’t sure if the 7 amps referred to Amp-hours. So converting to Watt-hours as we have two different voltage systems:

(1) Habitation capacity: 2 x 100Ah x 12.7V = 2,540 Wh
(2) E-bike capacity: 7Ah x 35V = 245 Wh

As a percentage, the e-bike will consume about 10% of habitation capacity (245/2,540 x 100% = 9.6%) or about 20Ah. Assuming an inverter efficiency of 85%, closer to 24Ah.
That’s a quarter of your available capacity. Not an insignificant amount but very doable if properly managed. How long you can stay off-grid in poor sunshine is another matter.

All the inverter does, is converts the 12 volts DC from your battery, into 230 volt AC. It won’t give you any power, in fact it used a bit itself, as nothing is 100% efficient. In relatio to size, go for one the next size up from what your maximum draw will be. Just remember if an appliance uses 10 amps on 230 volts, it will use approximately 200 amps on 12 volts, and that’s a serious draw, with cable size issues as well as flattening your batteries in minutes

I use a 1000w pure sine wave inverter to charge a 500w bosch battery,it certainly takes a fair chunk of battery to fully charge but as rambler says you need to manage your hab batteries wisely.
No problem in summer or when travelling but use it sensibly in the darker evenings.
Check this youtube link as there is a bit about charging via inverter later in the video.
Hope this helps.
Steven.

Just to put this into simple terms.

10 amps at 230 volts is like a good quality kitchen toaster.
The same power, but 200 amps at 12 volts is a small welding plant.
Both use the same amount of electricity per minute.

Back to charging the ebike, I would agree with Rambler sums in post 8, 10 % of your habitation battery used in a recharge per ebike.
However it is worth remembering that to keep your habitation batteries from deteriorating quickly, it is necessary to not discharge them below 50% regularly.

Something else to consider if you move the mh around alot on trips away. Fit an inverter (300/500 watt) on the engine battery with a relay which only works while the engine is running for recharging the ebike. This system would help on a non solar power day.
Malcolm

Guys please try and quote correctly, few of you making a right pigs ass of it lately (don't take offence )

guide here:

forum/topic.php?t=4345

It is a lot of current to charge the battery. I think Bosch made a 12 v charger but discontinued it. Could you buy another battery, should give you better range. We bought two e bikes with the same battery and that lets us do that. Also, you might be able to charge in a pub, if buying lunch

Many thanks to everyone for the very helpful and informative responses. I also gained a lot of excellent info from searching the previous Craicer posts on inverters. I purchased a 1500W pure sine wave inverter today. Probably a bit more than I'll need for charging the bike but I'm sure a hairdryer will appear at some stage. I'll more than likely be calling on the Craicer oracle again shortly for advice on fitting.