Off grid and no solar panel - run engine to charge?

[California4x4]

In people’s experience, if the twin auxiliary battery on an SE or Ocean has reduced in voltage enough for the fridge to go off. Does anyone know how long running the engine on tickover would take to fully charge the battery bank?

 

[Pieter4x4]

I recently saw my two auxiliary deepcycle batteries being restored from 78% charge to 99% by travelling only 20kms (12 miles), with the engine running about 20minutes. Obviously this was at engine speeds significantly higher than idle speed, and it was assisted by the alternator driving a DC-DC charger. (It was a night drive, so the alternator also had to drive the headlights). Also: the charge curve for batteries will not be linear, with the initial charging rate being higher than the rate once the batteries approach a full charge. A thumbsuck: I believe a 90minute idle should go a long way to charge the batteries to a level where another two days of fridge use should be possible. I would love to receive feedback on from others with more experience of this.

 

[willwander]

I think you’re right about the charge discharge cycle being non-linear, a bit like phones where you can charge to 80% quite quickly but the last 20% takes longer. We are into our 5th day off grid this weekend and the batteries have been at 60% for what seems like forever. I start the engine once a day and run on idle just for a couple of mins, mainly just to make sure the engine starts and we haven’t left the radio or interior lights on etc. It would be great to have a battery gauge on the starter battery too.

 

[kp64zl]

I reckon you will be fine for 5 days based on some calculations from my set up

Camping for 5 days using solar power- the controller has a useful Bluetooth app measuring energy consumption

I am using about 40 watt hours per day to run fridge (Dometic CFX28) plus a little lighting and charging phones

My beach battery is rated at 70 amp hours , apparently has useable 50 amp hours = 600 watt hours

Therefore based on my useage should last 15 days

So even If I am wildly out with calculations / estimates then 5 days should be fine without needing extra charge

I am in a Beach


EDIT: rechecked - 40 to 70 watt hours per day so more like 10 days estimate

 

[Elly Swanson]

Okay - thanks for your reply- does hookup charge better than engine - got a long drive before I get there?

We were fully charged via home hookup before going to Chester to sit on the racecourse for the food and drink festival (and not move) from Thursday lunchtime. Only used fridge and lights a couple of times. Left Chester this teatime. About 100 hrs and still had charge. We do a lot of festivals so hope this is a good omen.

Nearly forgot - we have an ocean.

 

[MelanieW1]

Ok - well I’m back! I arrived on site Thursday mid afternoon, having charged via hookup the day before followed by a 4hr journey. By Saturday night, the control panel said 60% so I ran the engine for about 20 mins. When I turned the engine off it said 100%, which I was a little sceptical about. Sunday morning it read 70% and by Monday midday when I left it read 60% So, I guess had I not ran the engine, it would still have lasted. I was running the fridge mainly on 5, charging a phone and running the heating overnight on 1. (Yes it really was that cold at night!) plus some LED lights on at bedtime.

Thank you very much for all your comments - much appreciated.

Melanie


Sent from my iPad using Tapatalk

 

[soulstyledevon]

Reading this thread makes me wonder why people install Solar...???
I would say 5 days is more than enough, especially given the recharge times from driving mixed in.

 

[willwander]

Ok - well I’m back! I arrived on site Thursday mid afternoon, having charged via hookup the day before followed by a 4hr journey. By Saturday night, the control panel said 60% so I ran the engine for about 20 mins. When I turned the engine off it said 100%, which I was a little sceptical about. Sunday morning it read 70% and by Monday midday when I left it read 60% So, I guess had I not ran the engine, it would still have lasted. I was running the fridge mainly on 5, charging a phone and running the heating overnight on 1. (Yes it really was that cold at night!) plus some LED lights on at bedtime.

Thank you very much for all your comments - much appreciated.

Melanie


Sent from my iPad using Tapatalk

Similar stats and usage to mine. We seemed
to be on 60% for ages.... then you panic lol. On mine it’s the heater that sucks the most juice although I still get almost 3 days with it on setting two/three pretty much the whole time.

 

[willwander]

Reading this thread makes me wonder why people install Solar...???
I would say 5 days is more than enough, especially given the recharge times from driving mixed in.

I think solar is great. I’ve been thinking about it. But as you say, in good weather, you can go for a while anyway. The times you really need it are when it’s dark, freezing and and you need the heater, but in those conditions you don’t get much sun anyway

 

[BikerGran]

I've used my van for up to 5 days with EHU. I hook up at home for 24 hours and put the fridge on at a cooler setting, and if I have room on the fridge, which I usually do as it's really quite large, I put in a 2 litre bottle of water I've previously frozen in my home freezer, then when I reach my destination I put the fridge on a higher setting.
I bought my van used so I can't be sure but I believe the leisure batteries are the originals, as it came with loads of history and no mention of new batteries. The van and therefore possibly the batteries, are now 12 years old.

 

[Skewif]

Reading this thread makes me wonder why people install Solar...???
I would say 5 days is more than enough, especially given the recharge times from driving mixed in.

Depends on how you use your van. In the summer can stop as long as I like charging leisure batteries, the e-bike, drone, laptop, phones and the engine battery so can use the radio as much as wanted with solar. Just one less thing to worry about.

 

[soulstyledevon]

Depends on how you use your van. In the summer can stop as long as I like charging leisure batteries, the e-bike, drone, laptop, phones and the engine battery so can use the radio as much as wanted with solar. Just one less thing to worry about.

I could see the use for recharging ebikes.
Can solar recharge an ebike battery fully...?

 

[Loz]

I could see the use for recharging ebikes.
Can solar recharge an ebike battery fully...?

You would need a second set of batteries, cos’ you’re out riding when the sun is shining..

 

[soulstyledevon]

You would need a second set of batteries, cos’ you’re out riding when the sun is shining..

I’m guessing the solar re-charges the van batteries whilst out riding and then the van charges the bike battery later in the day...?

 

[soulstyledevon]

Just wondering what drain ebikes have on the leisure battery...

 

[MattBW]

Just wondering what drain ebikes have on the leisure battery...

My ebike is 36v battery so even if I had a charger I imagine it would be quite a drain on a 12v setup.

 

[Jabberwocky]

We (two of us) have just returned home from being away without hook up for 4 days/nights. We didn't know how long our leisure batteries would last so we did the following to minimise risk of having flat batteries and to give some clues as to how long we could go without any recharge (Target - discharge to no less than 40%):

• 24 hour hook-up charge before leaving home.
• Switched on fridge (level 6) the night before leaving.
• Made sure Cali courtesy lights are switched off.
• Leave engine running whilst pop-up roof put up. (Also helps remember to switch of ignition when roof fully up)
• Parked up with the fridge side of Cali facing North. (much cooler)
• Avoid using (therefore need to charge) phones/iPad/Laptops etc - it makes for a more chilled weekend away too
• Used Cali cold water tap in normal way (hot drinks, Washing up, teeth cleaning, simple wash etc. No site facilities except loos)

We ended up with 60% still remaining on the control panel. Would have been happy to go six 6 days without charge. Home was about 12 miles away and battery reading returned to 100% by the time we got back. Driving conditions were non congested city driving.

Annoyingly, we had neighbours who were not on the same page as us. Engines left running and across the way a generator!

I hope this post is of help/is interesting. If anyone has more tips please post here. (Not about my Neighbours please)

 

[Skewif]

Just wondering what drain ebikes have on the leisure battery...

The battery on my bike is 500wh. so about 30% of total leisure battery capacity. Never really use more than half the batt as the dog doesn't have the stamina. Charge it either before I go or on return depending on the sun. 200W of solar has no problem keeping up as on a good day they produce almost as much as the 3 hour charger is taking.

 

[Elly Swanson]

Seems a bit inconsiderate idling a vehicle on a campsite with regards to diesel fumes and their well reported ill effects on air quality and health

We were at a festival last year when someone turned their engine on to charge and their exhaust was blowing straight in to us (we were front on, they were side on). It was awful. We explained and asked them to turn it off very politely but they really didn’t care. We’re assertive people and they begrudgingly did switch off. It nearly turned nasty and I think if we’d have been less assertive they would probably have told us to pee off (or worse). The bloke spent the rest of the time loudly moaning about us to his very embarrassed partner, which didn’t bother us at all, but must have spoiled their weekend!

 

[soulstyledevon]

The battery on my bike is 500wh. so about 30% of total leisure battery capacity. Never really use more than half the batt as the dog doesn't have the stamina. Charge it either before I go or on return depending on the sun. 200W of solar has no problem keeping up as on a good day they produce almost as much as the 3 hour charger is taking.

View attachment 43924

View attachment 43925

So can you connect the ebike battery to the solar Controller...?
How exactly are you charging the bike battery when not on hook-up?

 

[kp64zl]

So can you connect the ebike battery to the solar Controller...?
How exactly are you charging the bike battery when not on hook-up?

Good question - I was going to ask the same -- is there a way of switching between leisure battery and another one (e.g. ebike, lithium battery, etc)? perhaps @Loz will have the answer!

 

[WelshGas]

So can you connect the ebike battery to the solar Controller...?
How exactly are you charging the bike battery when not on hook-up?

Good question - I was going to ask the same -- is there a way of switching between leisure battery and another one (e.g. ebike, lithium battery, etc)? perhaps @Loz will have the answer!

Use a suitable Inverter, not the California one in an Ocean/SE , to power your usual eBike Mains Charger or a suitable 12-36v Charger but these aren’t common and may have to have a direct connection to the Leisure Battery.

Charging E bike batteries

I have a 375W battery for my ebike. My 2009 Cali has the standard inverter which I propose to use for charging the battery. The manual is unclear to me as to whether I can charge the battery using this. I think I can charge whilst travelling but I would also like to charge whilst stopped but not...

vwcaliforniaclub.com

 

[Skewif]

So can you connect the ebike battery to the solar Controller...?
How exactly are you charging the bike battery when not on hook-up?

I just use the std 230v bike charger plugged into a 300w inverter connected via a heavy duty fused cable to the leisure battery under the seat. Would be more efficient using a 12v charger but they take 7 hours to fully charge so not so handy.

 

[Loz]

If you have the Bosch e-bike system, they do a 12v charger, saves having an inverter and the associated losses going up to 240 and back down to 36.

Bosch eBike 12v Travel Battery Car Charger – e-bikeshop.co.uk

New 'on the fly' 12v travel charger for Bosch eBike battery packs. Today we announce the new 12v car cigarette socket charger available for 300Wh & 400Wh..

www.e-bikeshop.co.uk

 

[MattBW]

The battery on my bike is 500wh. so about 30% of total leisure battery capacity. Never really use more than half the batt as the dog doesn't have the stamina. Charge it either before I go or on return depending on the sun. 200W of solar has no problem keeping up as on a good day they produce almost as much as the 3 hour charger is taking.

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View attachment 43925

Wow thats quiet an impressive output! What panels do you have that are 42v?