Re-charging Leisure Batteries Off Grid

[JasonW]

So a quick question for the people in the know....

I have 2 x 110Ah leisure batteries, connected to a 250 W panel and dc-dc charger....

I am told the dc-dc charger will put in ~20A an hour with the engine running and the panel will put in ~15A an hour on a sunny day....

I am wondering if it's possible to connect the EHU to a 2000W petrol suitcase style generator if I need a decent re-charge... If so how many amps per hour would that put back in...?

 

[czmate1999]

interesting, think @Dellmassive might be the guy for you on this one! Would definitely suggest swapping out the two 110ah batteries for 1 larger Ah lithium battery. Will save you weight, space, charging time and give you more available power . Should pay for itself when compared to buying replacement normal leisure batteries too... (PS. all in my humble opinion )

 

[Dellmassive]

None.

Unless you have a smart battery charger as part of your EHU setup in the van.

All you need to do is add in a charger for your Leisure setup, and possibly a smaller second one to maintain the starter.... or a duel output unit like the victron that could charge both.

Then you can use EHU from either plug in or genny.

For AGM look for 10-20A per 100ah battery.... so 30A charger would be ideal..... a 15A charger would work too, . . . . But just take twice as long to charge..

Have a look here>

*******************

EHU 240v Chargers:

Victron Energy Blue Smart IP22 Charger 12/30(1) 230V - https://amzn.to/34QoQYD

Victron Blue Power IP65 Battery Charger with built-in Bluetooth Blue Smart IP65 Charger 12/15A) - https://amzn.to/36VeyrE

NOCO Genius G15000UK 12V/24V 26A Pro Series UltraSafe Smart Battery Charger - https://amzn.to/2Sl78Kk

CTEK 40-003 Vehicle Battery Charger - https://amzn.to/2MoJ7hr

CTEK CTE-56329 CTEK Direct Connector Adaptor (10mm) - https://amzn.to/35XkG2E

CTEK 56-870 Comfort Indicator Cig Plug - Black - https://amzn.to/34NkBgf

**************************************************


Victron for a multi-chanel version that can charge BOTH the starter and Leisure seperatly . . .

eg: 12v 20A 3chnl - https://amzn.to/2R8zqXi

 

[Salty Spuds]

So a quick question for the people in the know....

I have 2 x 110Ah leisure batteries, connected to a 250 W panel and dc-dc charger....

I am told the dc-dc charger will put in ~20A an hour with the engine running and the panel will put in ~15A an hour on a sunny day....

I am wondering if it's possible to connect the EHU to a 2000W petrol suitcase style generator if I need a decent re-charge... If so how many amps per hour would that put back in...?

If you’re going to lug a smelly petrol genny & fuel around, just on the off chance that you might need to charge your leisure batteries, why not just run that big diesel genny that sits under the bonnet?

 

[Dellmassive]

If you’re going to lug a smelly petrol genny & fuel around, just on the off chance that you might need to charge your leisure batteries, why not just run that big diesel genny that sits under the bonnet?

Remember, there AGM..

So he will running the van for hours.. .

But a valid point and another good reason to look at Lithium.

 

[JasonW]

If you’re going to lug a smelly petrol genny & fuel around, just on the off chance that you might need to charge your leisure batteries, why not just run that big diesel genny that sits under the bonnet?

Yes, I was looking for a quick charge solution... 2 / 3 hours max. I would need to run the engine for 10 hours to put 200 amps in without any current draw

 

[JasonW]

Remember, there AGM..

So he will running the van for hours.. .

But a valid point and another good reason to look at Lithium.

Lithium isn't an option for me just yet as battery location under the driver / passenger seat meant I couldn't find a Lithium with a low enough height dimension to fit... And I did a lot of searching... They were all just too tall by about 20mm which gave the converter a headache and meant I couldn't swivel the seats... They needed to be lower profile under there

Probably as technology advances and they become smaller / same height dimension as the low profile AGM batteries then it's a better option.

 

[JasonW]

So @Dellmassive regarding the smart charger

I am told by the converter that I can charge my leisure batteries straight off the mains... i.e plug the EHU in night before setting off on a trip to fully charge up the leisure system... So I assume it must have a smart charger fitted for that side of the power system.

So with that in place I am assuming I should be able to charge off the genny in the wild through my EHU ... But i was hoping to achieve a faster charge than the dc-dc charger under the bonnet which is ~20A per hour.

So off the genny I'm still going to be limited by the smart charger rating..?

I'll try and find out what this is rated at..

 

[travelvolts]

Also, bear in mind that the Victron chargers with 2 or 3 outputs divide the total charging current between the outputs. For example, you wouldn't get 3 x 30 amps, you would get 3 x 10 amps.

 

[Long tall John]

Lithium isn't an option for me just yet as battery location under the driver / passenger seat meant I couldn't find a Lithium with a low enough height dimension to fit... And I did a lot of searching... They were all just too tall by about 20mm which gave the converter a headache and meant I couldn't swivel the seats... They needed to be lower profile under there

Probably as technology advances and they become smaller / same height dimension as the low profile AGM batteries then it's a better option.

Relion do a low profile 100ah

 

[Salty Spuds]

Lithium isn't an option for me just yet as battery location under the driver / passenger seat meant I couldn't find a Lithium with a low enough height dimension to fit... And I did a lot of searching... They were all just too tall by about 20mm which gave the converter a headache and meant I couldn't swivel the seats... They needed to be lower profile under there

Probably as technology advances and they become smaller / same height dimension as the low profile AGM batteries then it's a better option.

Are yours factory swivels?

 

[Salty Spuds]

Also bear in mind that the highest charging rate for your setup is around 2x20A which is 40x12=480W so your 2kVA genny is waaay overkill.

 

[JasonW]

Relion do a low profile 100ah
View attachment 58754

I looked at this one.... but had to be 170mm max height....

 

[JasonW]

Also bear in mind that the highest charging rate for your setup is around 2x20A which is 40x12=480W so your 2kVA genny is waaay overkill.

Thanks for putting that into perspective... a 1KW should be plenty then.

 

[t0mb0]

Is this something you’ve actually needed in practice or more a theoretical issue? I’m asking because, after wild camping a reasonable amount, I’ve never come close to wanting anything other than my solar and dc-dc setup. What is it about your requirements that is so extreme?

 

[JasonW]

Is this something you’ve actually needed in practice or more a theoretical issue? I’m asking because, after wild camping a reasonable amount, I’ve never come close to wanting anything other than my solar and dc-dc setup. What is it about your requirements that is so extreme?

more theoretical but I'm likely to be parked up stationary at the side of a lake for between 7-10 days, quite possibly in the shade... current draw won't be excessive (fridge/tv/charging devices/music etc but could be prolonged without charge... so was looking at alternative charging methods off grid

 

[t0mb0]

more theoretical but I'm likely to be parked up stationary at the side of a lake for between 7-10 days, quite possibly in the shade... current draw won't be excessive (fridge/tv/charging devices/music etc but could be prolonged without charge... so was looking at alternative charging methods off grid

For that kind of likely power draw, I would think a 50a dc-dc would be more than sufficient as a backup and would save having to lug around a generator. I certainly wouldn’t be running to buy a generator without proving the dc-dc route won’t cut it for some reason.

 

[t0mb0]

For that kind of likely power draw, I would think a 50a dc-dc would be more than sufficient as a backup and would save having to lug around a generator. I certainly wouldn’t be running to buy a generator without proving the dc-dc route won’t cut it for some reason.

To put it another way, your max current input isn’t limited by the alternator capacity, it’s limited by the maximum current acceptance of your batteries so a generator just can’t help.

 

[JasonW]

For that kind of likely power draw, I would think a 50a dc-dc would be more than sufficient as a backup and would save having to lug around a generator. I certainly wouldn’t be running to buy a generator without proving the dc-dc route won’t cut it for some reason.

Thanks @t0mb0 - I will look at the dc-dc method first...