Inverter/Solar/Deep-cycle set up for E Bikes

coastsider

Adventurer
Hi guys, can anyone give me some advice? My SoCal Tear drop has two linked Diehard deep-cycle batteries, solar controller and guest charge pro, using x2 78w Flexopower panels for a total 158w (max 19.2v) to top up batteries. I'm no electrician, to be honest it baffles me, I have 3 Bosch 500w (32v) ebike batteries that I want to charge in the field from the trailer along with running the Engel fridge, LED lights and charging a couple of iPhones, it's only the ebike batteries that will run through the inverter everything else is already wired through the trailer. I understand I will need a high output pure sine inverter to handle the extremely high draw the three ebike batteries will need (hoping to charge all at the same time). Will a 6000w high quality inverter work? I know I've probably excluded a lot of other data and info needed to really answer fully, really I guess I want to know what size unit I need. Thank you in advance.

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luthj

Engineer In Residence
What is the e bike battery capacity in AH or kilowatt hours? The same goes for your die-hard batteries.

I suspect you probably have much to small of a system to change the e bikes regularly.
 

dreadlocks

Well-known member
I would get a different, higher voltage solar panel (or rewire yours in a series w/MPPT) and a solar controller that can do 32v (Victron can) and use it for charging the bike batteries directly.. otherwise it sounds like your going to overload your house electrical.. keeping your fridge running is likely far more important than charging your bike and you wont have the losses of converting 12VDC -> 120VAC -> 36VDC..

I'm seeing a future where I might have an electric dirt bike or ohv or even cheap golf cart.. so I'm building a solar electrical system powerful enough to output either 12/24/36/48v.. I figure I can put a battery switch on the controller output, with a powerpole connection, connect to the Victron charger w/bluetooth and load a different battery charging profile from saved file and then hook it up to whatever toy it happens to be.. kinda clumsy but it should be doable, probably needs a lock out incase it gets switched back to house @ 48v accidentally it wont hurt anything.. but if I can get away with recharging the toys on the road every few days when we have plenty of sunlight and the fridge/house battery can be maintained w/the TV Alternator.. show up at camp and everything have a full charge for the next few days til we jump to another location.

I'm planing on alot more solar capacity tho, I dont think 150W is going to be enough to recharge anything larger than a hoverboard in a reasonable time.. how big are these e-bike batteries?
 
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LeishaShannon

Adventurer
Best bet is a DC input charger for your e-bikes. Look on the hobby sites like hobbyking.com, you'll find chargers that can take 12v in and output 36v or whatever. This is the most efficient way as you're not converting DC to AC then back to DC.
In addition to this you'll also want a lot more solar or the ability to charge your batteries from the alternator.
 

dwh

Tail-End Charlie
Doing a quicky search, according to this,

https://www.bosch-ebike.com/en/products/charger/

Bosch's chargers are 2a, 4a or 6a output @ 36v.

amps x volts = watts

That would be 72w, 144w or 216w. Even accounting for a bit of loss, you could run three of the 6a units from a single 1000w inverter.

Well, you could except that only the 2a unit can run off 110v...the other two are 220v units.

Maybe they have different chargers available in the north American market?

The "500" batteries' specs show 500 watt*hours or 13.4 amp*hours (@36v).

To recharge one 500 watt*hour battery with 150w per hour of solar, you'd need over 3 hours of full solar output.

But since solar rarely puts out full wattage, you could probably recharge one of those batteries per day...if your electrical system isn't doing anything else, like running a fridge.
 

dwh

Tail-End Charlie
Also, most everything can run from a modified square wave inverter. It's extremely rare that a battery charger or power supply needs a sine wave inverter.

(FYI: There is no such thing as a "pure sine wave" or "modified sine wave" inverter. That's just marketing BS. They are either sine wave or modified square wave. If they are sine wave, then the wave doesn't need to be modified. Only square waves need to be modified. The inverters in ACP UPS units for computers are modified square wave inverters.)
 

coastsider

Adventurer
I would get a different, higher voltage solar panel (or rewire yours in a series w/MPPT) and a solar controller that can do 32v (Victron can) and use it for charging the bike batteries directly.. otherwise it sounds like your going to overload your house electrical.. keeping your fridge running is likely far more important than charging your bike and you wont have the losses of converting 12VDC -> 120VAC -> 36VDC..

I'm seeing a future where I might have an electric dirt bike or ohv or even cheap golf cart.. so I'm building a solar electrical system powerful enough to output either 12/24/36/48v.. I figure I can put a battery switch on the controller output, with a powerpole connection, connect to the Victron charger w/bluetooth and load a different battery charging profile from saved file and then hook it up to whatever toy it happens to be.. kinda clumsy but it should be doable, probably needs a lock out incase it gets switched back to house @ 48v accidentally it wont hurt anything.. but if I can get away with recharging the toys on the road every few days when we have plenty of sunlight and the fridge/house battery can be maintained w/the TV Alternator.. show up at camp and everything have a full charge for the next few days til we jump to another location.

I'm planing on alot more solar capacity tho, I dont think 150W is going to be enough to recharge anything larger than a hoverboard in a reasonable time.. how big are these e-bike batteries?
The Batteries are 500w each
 

dreadlocks

Well-known member
Looks like your battery bank is 200aH combined, 50% discharge would be 100aH.. 100aH x 12v = 1200W..

You could recharge two batteries with your current power system, omitting all other power uses like your fridge.. then how long does it take to recharge from a ~50% state back to 100% with that 150W Panel? Since you have a fridge, your probably only going to want to charge one battery, wait for power to recover and then do the next.. if your wanting to recharge all 3 batteries daily then your beyond your means, if you just need to recharge one a day then you can probably get it to work if you get plenty of sunlight.. or one every few days if your sun exposure is not optimal.

Also keep in mind the more amps you pull out of your battery bank the less capacity it has, you wont want to fast charge in this case or that 1200W of battery capacity might only end up being 600W if your using a high amp charger or multiple low power chargers concurrently through an inverter.. slower will be better since your transferring power from lead to lithium.
 

dwh

Tail-End Charlie
The Batteries are 500w each

Not exactly. They are 500 watt*hours each.

Which means they can put out 500 watts for 1 hour, or 100 watts for 5 hours, or 50 watts for 10 hours, or whatever.

Same goes the other way for charging. Charging at 100w you'll need 5 hours to supply 500wh.
 

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