Charging e-bikes from solar

[Louisesjpp]

When camping off-grid, how can I charge e-bikes overnight? The two bikes are 48V, a 650Wh battery on each.

I understand that there are boost controllers that output 48V but I'd need a battery pack at 48V too. I guess the alternative is to charge 12V batteries and then boost the voltage to the charger.

What do you guys do and how well does it work?

ps the bikes will get extensive use, so a charge overnight is probably needed, I doubt we'd be able to charge enough during the day because we'll probably be out on them

 

[Richard n Ann]

Just use a pure sine wave inverter and the charger that came with them

 

[Guigsy]

You might be able to get a 12v DC charger for the batteries. But going via a 230v inverter is only going to cost you a few percent loss.

The biggest issue is that 650Wh of batteries are equivalent to 54Ah of leisure battery power. If you were to charge them overnight on lead-acids, you'd need roughly 200Ah of leisure batteries, which would be flat in the morning.

 

[Richard n Ann]

Hopefully the batteries will just need topping up though

 

[Guigsy]

Hopefully the batteries will just need topping up though

Getting over 100Ah of solar recharging per day is a big ask. Even in the peak of summer on a cloudless day, you'd need about 400w of panels. And several times that if it's cloudy or spring/autumn.

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[Ivory55]

Generator

 

[Lenny HB]

We have a 1000 watt pure sine inverter but only charge one bike one day and the other one the next day & try to charge them when only partly discharged.

We have 300 watts of solar & 240 ah of Gel batteries we would only risk charging both the same day around mid June. Our bike batteries are 400 watt. Even then it would take a few days for the hab batteries to fully recharge.

 

[Richard n Ann]

These are the latest thing apparently... All you do is buy a special liquid and put it in, then there is nothing else to worry about. No charging or connecting anything up, no need to worry about how long it will go for or if your going to get home. It's special liquid "motor" is much more powerful too so it can easily take 2 people.. And get this, AT CAR SPEEDS! Imagine that

It's a great time to be alive

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Disclaimer: Actually I'm just joking, no offence to anybody - enjoy your bikes

 

[LesW]

I use this to keep our batteries topped up, without an inverter.

12V Car Cigarette lighter invert to 42V 1.5A light duty Charger for 36V battery | eBay

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[Louisesjpp]

A lot of good points made here, thank you. I'm trying hard to make the e-bike thing work but as I kill a battery in less than three hours hard riding in the mountains, it is looking like a big ask for off-grid use. Maybe that scoort idea isn't so bad after all:

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[Richard n Ann]

A lot of good points made here, thank you. I'm trying hard to make the e-bike thing work but as I kill a battery in less than three hours hard riding in the mountains, it is looking like a big ask for off-grid use. Maybe that scoort idea isn't so bad after all:

If you use ACSI sites they are reasonably priced and come with hook up included

 

[autorouter]

If you want to charge 1300Wh of bike battery from a leisure battery bank, you would need something at least twice that capacity if lead acid, so that's 2600Wh, or 2600/12 = about 220Ah. Charge them during the day, and use the stored charge at night to charge the bike batteries.

I don't know how these higher performance bikes are constructed, so are the batteries detachable? If so there's another possibility. Buy two extra batteries and charge them during the day, swap them ready for the next day. You'd need a good set of solar panels, at least 400W.

A Victron solar controller can be set to charge 48V lithium batteries directly, no inverter or extra charger needed. The larger units can do 48V, such as this one.

Energy Solutions | Victron SMART BlueSolar Charge Controller - 150/35A

Energy Solutions | Victron BlueSolar SMART CHARGE Controller With terminal clamp Connection - Auto Select Voltage - 12/24/36/48v - 150/35A (SCC115035210)

www.es-store.co.uk

 

[Landy Andy]

I don't know how these higher performance bikes are constructed, so are the batteries detachable? If so there's another possibility. Buy two extra batteries and charge them during the day, swap them ready for the next day. You'd need a good set of solar panels, at least 400W.

The batteries are removable but sometimes not easily. Main issue is the cost as they tend to be £600-£1000

 

[jumar]

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

Previous Forum posting to read while your batteries are charging.

 

[autorouter]

The batteries are removable but sometimes not easily. Main issue is the cost as they tend to be £600-£1000

An alternative, if you have a charged 12V battery bank, and you want to charge a 48V bike battery, you could use a 12V to 48V B2B as a battery-to-battery charger. It will have a D+ trigger to switch it on, which can be activated by simply supplying 12V with a switch. it will then charge the 48V batteries until they are full or the 12V side is empty.

12V to 48V B2Bs are a bit hard to find, but Sterling do one. It's 70A at 12V, but it has a half-power mode (35A) if you prefer that.

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[Louisesjpp]

If you want to charge 1300Wh of bike battery from a leisure battery bank, you would need something at least twice that capacity if lead acid, so that's 2600Wh, or 2600/12 = about 220Ah. Charge them during the day, and use the stored charge at night to charge the bike batteries.

I don't know how these higher performance bikes are constructed, so are the batteries detachable? If so there's another possibility. Buy two extra batteries and charge them during the day, swap them ready for the next day. You'd need a good set of solar panels, at least 400W.

A Victron solar controller can be set to charge 48V lithium batteries directly, no inverter or extra charger needed. The larger units can do 48V, such as this one.

Energy Solutions | Victron SMART BlueSolar Charge Controller - 150/35A

Energy Solutions | Victron BlueSolar SMART CHARGE Controller With terminal clamp Connection - Auto Select Voltage - 12/24/36/48v - 150/35A (SCC115035210)

www.es-store.co.uk

Charging spare bike batteries during the day is a great idea, except they cost £700 each Any which way, keeping an e-bike going off-grid is looking expensive.

 

[Louisesjpp]

A Victron solar controller can be set to charge 48V lithium batteries directly, no inverter or extra charger needed. The larger units can do 48V, such as this one.

Energy Solutions | Victron SMART BlueSolar Charge Controller - 150/35A

Energy Solutions | Victron BlueSolar SMART CHARGE Controller With terminal clamp Connection - Auto Select Voltage - 12/24/36/48v - 150/35A (SCC115035210)

www.es-store.co.uk

Would this controller output 48V from 12V batteries when the panel is not active, ie, at night?

 

[Kannon Fodda]

How often do you move your MH, or do you tend to arrive at once site and stay there a few days? If you do move every other day or so, and would then drive for a couple of hours a decent B2B charger between engine and hab battery gives a good chance to recharge it if you have taken so much out that solar can't put it back. But your recharge rate may be limited by the rate at which your battery can absorb the charge.

You are probably best with an inverter, 12V to 240V and can then use your standard e-bike battery charger. If you can set your inverter up direct from the hab battery, rather than through wiring that is perhaps turned off by some safety system typical of UK MHs when the engine is started, you can recharge whilst driving.

The recharge units that plug into a cigarette lighter socket will take forever to recharge a 650 e-bike. The current allowed through the typical cigarette lighter will be too low.

A second option is to buy another bike battery so you at least arrive at site with them fully charged. Of course the bike batteries are seriously expensive so other options may prove cheaper. But this way you do start with more e-bike battery and if only staying for 3-4 days, you only need one recharge before you move on.

But the real answer has to be to improve the overall capacity of your habitation battery bank so that you can hope to recharge the e-bike and have enough for other van use. Again it's going to be expensive, and you may also need to watch the weight of your batteries if your MH payload is challenged. For me Lithium habitation battery where you can use 90% + of the total without risk of real damage, combined with a 60A B2B was the answer with only 100W solar and no real space on the roof for much more. I already had a second e-bike battery as I often needed to extend rides beyond one 500 battery capacity. I don't cycle every day but can now stay on site for say 5 days without hookup with enough to recharge at least one of those batteries from flat.

 

[Toady]

Just travelled 3 hours in Spain. Both bikes on charge using B2B Sterling 60A. Parked up now and 185A solar panel finishing with top up charge.

 

[jumar]

Just travelled 3 hours in Spain. Both bikes on charge using B2B Sterling 60A. Parked up now and 185A solar panel finishing with top up charge.

Equals one of our many different charging routines.... we've just managed 3 days riding in different areas... each eating into our bike battery, but replenished by Solar, Battery pack and alternator....

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