Extra Battery Dilemma.

So here is my dilemma.

 

I have been trying to locate a Bosch 12v Travel charger for my ebike, so I can charge the battery when in the campervan.

 

Sadly I cannot find one anywhere, as they appear to be no longer available, why I don’t know.

 

So I was thinking about a second bike battery, so I head off with two fully charged batteries for say 2 days cycling, back to the camper at night new battery for the next day.

 

The other option is an inverter in the Camper to plug in my mains charger, but I think it would drain the leisure batteries (and I have 3 off them) as it needs to be on for 5-6 hours, and the inverter option is not that efficient, ie, convert 12v batteries to mains back to 48v to charge the bike battery

 

Anyone else have any ideas, just think the second battery is the best option, and charge both before I go. ??

I'd say second battery, but then keep both in use by rotation even when not using the camper to keep both in good equal condition.

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I've had a similar dilemma myself but concluded that it wouldn't be practical to charge an e-bike via leisure battery and inverter. The demand would be too high and risk draining the leisure battery. Maybe it would be possible if driving for the entire duration of the charging but this isn't always practical either. I opted for a second battery instead.

I guess the second battery will always come in handy if I want to go "beyond the range" of one battery.. so a second battery looks the way to go, also I suppose if I am at a caravan site and have hook up, I can recharge till my heart is content

Yoda says ... "Hmmm, think outside the box, you must"

 

Get a 4 amp charger then after a hard days riding pop into a local pub or restaurant and ask them to charge it up for you whilst you relax (only costs them 30 pence).

 

Just leave enough time for a few beers or pudding and pick it up again when settling the bill.

Yoda says ... "Hmmm, think outside the box, you must"

 

Get a 4 amp charger then after a hard days riding pop into a local pub or restaurant and ask them to charge it up for you whilst you relax (only costs them 30 pence).

 

Just leave enough time for a few beers or pudding and pick it up again when settling the bill.

 

Only one small problem there Bikey,

 

some of the places I park..... are miles from anywhere, and in the middle of nowhere.

I know ... I know...

 

Always wanted a camper van but always thought they go hand in hand with an external petrol generator - something like a Honda EU10i.

 

Honda seem to make a good motor so always though they would be handy to have if touring.

How about using a DC-DC buck/boost converter should be more efficient than turning to AC then back to DC

 

i have 2 that turn 1-35v upto 7amps into variable 1-35v at 5amps they CC/CV so charge my 2 24V batteries up which i then series up to get my full power

http://www.hi-powercycles.com/hpc-suncapture-300-folding-solar-panel-and-charger/

 

way to expensive but you could diy something like this from bits of ebay

There are 1200Wh in a 12v 100ah (typical leisure battery size) battery. I can't see a solar system charging a Bosch battery. I'm pretty sure it will have to handshake with the charger before it will work.

https://www.sunshinesolar.co.uk/prodshow/600W___12V_Pure_Sine_Wave_Sunshine_Power_Inverter_C_Series/C60012.html?gclid=Cj0KCQjw9ZDeBRD9ARIsAMbAmoapJN3FJNBKtq-1kCKe-ScyiYFkyRkq0ZE5TeAEW0lw3gLnb6rjH4oaAtjqEALw_wcB

I have been trying to locate a Bosch 12v Travel charger for my ebike, so I can charge the battery when in the campervan.

...

The other option is an inverter in the Camper to plug in my mains charger, but I think it would drain the leisure batteries

 

I'm curious as to why you think the inverter option will drain your leisure batteries, but the 12v travel charger won't ?

 

You need to pump 400/500wh into the battery regardless of what's doing it.

 

??

Hi GLJoe,

 

what you say is perfectly correct, in that I will have to put that amount back into a battery no matter how I do it.

 

However as nothing is 100% efficient, if I were to take the 12V from the batteries and through an inverter change this to 240V AC, for my mains charger, I would loose a percentage right there, as inverters are quoted as typically 85% efficient.

 

Then the charger would loose a small percentage again changing it back to the, I think 48V, to charge the bike battery, again not 100% efficient.

 

So inevitably I would use more power from my battery bank than necessary, and having a limited supply, as these batteries are required for everything else 12V, you run the risk of... say having no lights.

 

A mains inverter is a big drain on 12V batteries what ever you are running from it.

 

I was hoping to get the 12V charger, so I can go direct from 12V to charging the bike, with lower losses.

 

In hindsight, a second battery will probably be the best option, as I could even charge both at the same time, if I were to plug my campervan into the mains - hook up as they say.

https://www.anker.com/deals/powerhouse2

 

what you want is a 5kw version of that

i think the best bet for a 12v bosch charger is the german site.

 

https://www.pedelecforum.de/forum/index.php

 

as i also cant find one anywhere ?

Looks good soundwave.... until you do the calculations

 

It says it's 434Wh (watt Hours) and at 12V thats only 36Ah (amp hours)

 

My camper van will have at least 350Ah, when it's finished.

 

Anyway have you tried to carry a leisure battery with one hand

if you got the cash get jimmy to build you a power wall from 18650s for the van.

 

prob wont pass a mot tho so best make it removable

 

http://www.evwest.com/catalog/product_info.php?cPath=4&products_id=463&osCsid=0qsp309oilj3licmipv5iog971

Might need to upgrade the suspension as well

yeah but i bet no one else can run a tumble dryer and a power shower

That's one way of getting clean after a muddy ride

 

inverters are quoted as typically 85% efficient.

 

I think that's probably the (cheaper) modified sine ones (which you may very well want to avoid using anyway!). I seem to recall the better quality pure sine ones are more like 92-95% percent efficient. I'll check on that though.

 

 

I was hoping to get the 12V charger, so I can go direct from 12V to charging the bike, with lower losses.

 

Ok, but the 12v charger needs to be a step up converter. That itself is going to have losses. If I have some time tomorrow, I'll see if I can find some typical figures, but I've got a feeling that there isn't going to be much in it. Depending on the design, the efficiency of the 12v charger could even possibly be worse! (although I imagine Bosch will have a pretty good design)

 

Also, wouldn't the 12v charger need somewhere around 13A to give the equivalent of the standard 4A mains charger?

I'm sure some cigarette lighter plug fuses are only 10A. So I imagine the 12v charger is certainly going to be a slower charge system.

 

So I know what you're saying, but it wouldn't surprise me if at the end of the day, the actual total battery drain is not going to be a million miles different whichever way you decide, and its probably the convenience of the solution that's going to be the higher priority deciding factor.

(and it probably is the case that whichever way you charge, you might find that its going to drain a leisure battery too much -although you did say you had three!)

But I'm interested what your final findings are. I have a similar dilemma, and my solution has been a pure sine wave inverter, but use it to charge a pair of batteries when actually travelling from one place to another and the engine is running!

Agreed Jo,

 

and given the other constraints you have in the campervan, ie. how much water you can carry and how long before you need to empty the grey and black tanks, I would envisage having to visit civilization every few days, so I would simply recharge my "two" bike batteries. After all if I go away for 4 or 5 days, I don't want to be cycling all the time, a guy has to have some time off.

 

I'll keep the inverter for the microwave and my porridge

[/quoteI'll keep the inverter for the microwave and my porridge

 

 

https://www.youtube.com/watch?v=-HmWDdmTAE8

That'll cook the porridge alright.

Toured Europe in a Hymer Motorhome for 3 months each year for 10 years. Never stayed on campsites just cycling & walking the dog in the hills & mountains.

 

4 X 125Ah leisure batteries, 150W solar panels, Sterling B2B charger and an inverter that I can't remember the details of.

 

The batteries lasted 10 years.

 

Mains use:- washing machine, spin dryer, bread maker, toaster, satellite TV, charging computer & phone etc.

 

Took a Honda generator but left it behind after 2 trips as I never used it.

 

The fastest of the charging systems was the Sterling B2B. A friend copied my set up and lived in his MH full time. When batteries were getting low he just ran the van engine.