CTEK D250SA running parallel to BLUETTI Charger 1?

[Firedupinside]

Hi all,

First post but long time T6 Campervan owner.

Currently have a CTEK D250SA and Solar set up running to 2 Powersafe BS B14F batteries for power, however I have recently purchased a BLUETTI power bank and am now looking at installing the Charger 1, but not sure if I can run both the CTEK and Charger 1 in tandem off the main battery.

With this in mind and having watched a couple of videos, I’m now thinking if a transfer switch could work where I can run either charger at any one time and not overloading the main battery or the alternator when driving.

My question is, has anyone else done something similar to this and if so how did you wire the system?

Any guidance is appreciated.

Thanks

Jeremy.

 

[CAB]

What would be the total current if both at full chat?

That's what you will be taking from the alternator.

I've no idea what the alternator is rated for, but 1/2 to 2/3 of the rating would presumably be OK.

Welcome to the forum.

 

[roadtripper]

On the plus side the CTEK is relatively low current for a DC-DC charger compared to what's available now.

As a general rule of thumb don't draw more than 1/3 of the rated peak output of your alternator for a leisure system, and remember with losses DC-DC chargers always draw more on the input than they deliver as charging so check your manual. If nothing is mentioned assume 80% efficiency.

The Bluetti manual seems to suggest maximum 50A and the CTEK is 25A, so at 75A draw you're looking at needing a 200A plus alternator ideally, though if you are not regularly loading up both chargers you'll probably be OK on a 180A. If you have the 140A that might be an issue.

The usual solution is to put a small switch in the ignition sense line (as it's much easier there than the high current input line) but the CTEK doesn't have one (the red cable often called the ignition sense just enables the smart alternator behaviour) and as far as I can see neither does the Bluetti charger.

In fact the Bluetti charger manual makes little mention of how it protects the vehicle battery, just that it's "smart" - which is not helpful when planning a leisure system. I'd recommend it takes its power from an ignition switched source, though at a 50A draw that might be tricky.

 

[Jayjmac]

Reviving an old thread.. I’ve got a Renogy 50A DC-to-DC charger connected to a 200Ah battery. I’ve just picked up a Bluetti 100V2 and I’m looking for the best way to charge it quickly—using the 12V cigarette socket isn’t ideal and slow. Hooking it up to EHU is fine, but ideally I’d like to be able to charge while driving.

I was considering the Charger 1, but then realised I already have a DC-to-DC charger and wondered, Is there any way to tap into the output side of the Renogy to charge the Bluetti?

 

[Dellmassive]

Yes you can do that, assuming you have a decent lithium battery that can handle the load.

Not sure on the charher¹ settings page, but you will need to twerk the settings to get it charging nicely.

 

[Jayjmac]

I have Renogy lithium batteries and a Renogy 50A DC–DC charger. Could I run a fused cable directly from that to the Bluetti, instead of buying extra equipment? I’m just curious, as it seems like the Renogy is essentially doing the same job as the Charger 1—but I’m happy to be corrected if I’m missing something obvious.

 

[Dellmassive]

The bluetti1 charger works differently,

It boosts the 12 volt up to 36 volts to enable a higher charge through the solar input on the blue se portable power pack.

So as far as extra equipment yes you need the blueetti charger one

This can be run off your starter battery, but with the extra load of the 50 amp dc dc charger you will more than likely burn out your alternator.

You can run it off your existing lithium leisure battery..... Charge on and off settings as the voltage of the leisure battery will be lower than you would expect to get from the alternator.

You can make this adjustment with the eco flow version which I have and I have tested..



But I've not tested the blueetti version.

 

[Jayjmac]

Ah, I see — thanks @Dellmassive . I figured it wouldn’t be as simple as just hooking it up and going.

I’ve been exploring options for charging on the move, as I’ll be travelling wanted to utilise leisure and won’t always know when I’ll have access to EHU. Solar isn’t really an option since I don’t want fixed or fold-out panels. Using the 12V cigarette socket takes about 11 hours, but I’d really like to cut that time in half (or better). I’m wondering if a 12V–24V Victron could give me the extra wattage I need

 

[Dellmassive]

the bluetti1 charger connected to the leisure battery will work, - to charge the PPP.

the then the LB will be charged via the engine dc-dc charger.

 

[Jayjmac]

Sorry I was getting confused, easily done. Think I was making it more complicated than it needed to be.

Makes sense and I can then turn the charger 1 up and down via the app depending on needs. Cheers for the steer and helpful advice as always

I’ll update once fitted.

 

[step]

@Jayjmac did you ever set the Charger 1 up like this? I've a similar setup though with solar and thinking of going down this route of connecting the Charger 1 to the leisure battery so getting a quicker charge for the Bluetti

 

[Jayjmac]

@step I didn’t go down the Charger 1 route in the end. I’ve got a Renogy DC-DC charger for charging the leisure battery when the engine is running, and a Victron battery charger for charging the leisure battery on 240V hook-up. The Bluetti is then plugged into one of the rear 240V sockets to charge.

I’ve also got a cigarette lighter to solar panel connector lead so I can charge the Bluetti from the 12V system while driving, although I’m looking to upgrade this to a better connector, probably an Anderson.

It’s maybe a slightly backwards and not the most elegant setup, but I didn’t have the room for a fixed inverter. Charging is slower this way, but it’s more than enough for our needs as we very rarely don’t have 240V the Bluetti in our case is only used for the odd day without 240 and nothing heavy.

 

[Jayjmac]

Started using the Bluetti more and more when camping and wanted to improve how I was charging it on the move. The ciggy lighter socket and plug kept popping out which was annoying, and I looked at swapping to an Anderson type plug but couldn’t find a flush mount option that would integrate cleanly into my existing setup.

My leisure batteries are nearly always fully charged thanks to the Renogy DC-DC so I decided to put that to use. I’ve integrated a Victron Orion-Tr Smart 12/24-15 which charges the Bluetti from the leisure bank while driving, significantly faster than the ciggy lighter ever managed. The Victron Connect app lets you configure engine shutdown detection so it only runs while the alternator is charging, protecting the leisure bank when stationary.

Getting around 232W into the Bluetti via the solar input lead which is a decent rate. Yes there’s a 10-15% conversion loss through the Orion but with 200Ah of leisure capacity you could theoretically do a full charge of the Bluetti and barely dent the leisure bank. I’ve also set a voltage cutoff so the Orion stops at a set leisure battery voltage just to keep a comfortable buffer in there.

Probably not the most conventional approach but it works really well for how I use the van!