Ah yes that looks like the answer - Thanks
[Guide] DC-DC Charger (for leisure battery) -- How I Done It --
- Thread starter Dellmassive
- Start date
For my needs I'd like a reasonably priced lower power DC-DC as I'm only considering a 50ah LiFePo and I've just run into a really interesting charger just released by Sterling - the Sterling Power BB1225
Things I like about the spec sheet so far (I have a couple of tech questions in with them):
Things I like about the spec sheet so far (I have a couple of tech questions in with them):
- Doesn't need an ignition signal - it infers it from a vibration sensor
- Is bi-directional - this could be a killer feature if done well, if the leisure battery reaches high charge and the starter is low it will kick in the other way around. For folks with an EHU charger or good Solar this could really simplify things and have fewer devices
- Jump start - in an emergency you can force it to charge the starter battery from the leisure battery for 5 minutes to self jump star
- High claimed efficiency - this small one does away with the fan
- It has a breakout connector that allows you to connect a buzzer or indicator to replciate the fault status if it's installed out of the way in a cupboard or seat base
- It can take the full remote unit of it's larger variants - this does add quite a bit to the price though. I like the option, what I don't like is that some things that would be very useful to me (lower charge rates) are only configurable with the remote - not via any Konami move on the charger or via an app.
- The breakout includes a "+12v signal" that isn't noted quite what it does - hence questions sent. Possibly it signals when the charger things there is an engine run condition and could be used to switch other things on based on that, which would be very useful indeed...
Agree it’s a nice box and 25amps too.
My strong advice is 50Ah is too small. Especially if you have a fridge etc. it would need constant charging.
I have 480Ah by using 4x leisure battery’s overkill for most people but it means I can charge drone batteries (work) remotely with the inverter.
My strong advice is 50Ah is too small. Especially if you have a fridge etc. it would need constant charging.
I have 480Ah by using 4x leisure battery’s overkill for most people but it means I can charge drone batteries (work) remotely with the inverter.
I only need it to run the fridge on days out and lights for a few hours - we're a day trip van not a camper.
50ah should give us broadly the capacity of a regular AGM but be a lot easier to tuck under the seat bases.
I actually want to try and downrate the charger (which you can with the remote) as I want to repurpose the existing 30amp towbar feed to avoid disturbing much while I'm still in factory warranty.
So some updates on this. I've had a really good conversation around things on this charger with Sterling, they've quite responsive and it would be good to support a UK company.
- The +12v 50ma signal isn't actually anything useful, it's a legacy power connector that was used in testing and development.
- The manual is confused over Lithium profiles, they are correcting it now I've pointed it out. The unit does have a float mode on the Lithium profiles by default - the behaviour is that once the "full charge" voltage is reached it will let the voltage drop to the "float" voltage as listed in the table which is ideal for getting the most lifetime out of the cells. If the load is such that the voltage drops back full charge will kick in again. If you'd rather have no float and just cycle charge (as the CTEK does) this can be done using the BBR remote.
- There isn't anyway to configure the reduced charge rates without the BBR and the BBR isn't really good value for the BB1225 in a seat base (it's £100 on top of the £200 for the charger) - however Sterling have said if I want the reduced rates then they are happy to configure it before shipping (with the proviso that it will be lost if I do a full reset)
I also noted this interesting new charger coming that does Solar and DC-DC but is a plug and play unit using the common 50A Anderson connector. Potentially interesting for those building stand alone power boxes?
You must have been fortunate & spoken to one of the junior technical bods. If you’re put through to the head man, Charles IIRC, you’ll have had a different experience. Probably one of the rudest people I’ve ever spoken to, he should never be let anywhere near a customer facing role. Which is a shame, because the products are generally decent kit at a fair price point, even if they do look a tad “Fisher Price”.
Agreed. The confused appearance of these really puts me off. Their product artwork is a mash of colours, typeface, font sizes, and logos that just makes me itchy. If the visible stuff is inelegant, I’m not confident in the parts inside the box. For example, we have a vestigial connection left on, and incorrect manuals.
Shallow of me I know!
Redarc bcdc clone?
I've used Sterling inverters quite a few times in marine applications and never had an issue with the kit or the support. It was one of the Sterling's I spoke to.
Like the other kit I've used (Merlin Equipment) the appearance tends to reflect the low run niche manufacturing aspect. I guess I'm used to that prototype/industrial look from the day job. I do wish Sterling's docs were a bit more like Merlin's though, even though both are clearly written by engineers without the assistance of technical authors. Too few companies (big ones included) remember that docs are part of the product not a nice to have.
Like the other kit I've used (Merlin Equipment) the appearance tends to reflect the low run niche manufacturing aspect. I guess I'm used to that prototype/industrial look from the day job. I do wish Sterling's docs were a bit more like Merlin's though, even though both are clearly written by engineers without the assistance of technical authors. Too few companies (big ones included) remember that docs are part of the product not a nice to have.
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Random question, I have noticed people's wiring going into their dc-dc chargers seem to have connectors on the end. What type are they? This is for chargers that have the screw down type clamp attachment, i.e. the victron Orion. I just left mine as plain wire and clamped it in!
Got an example?
I use 50A Anderson conections, but that's just me for swapping kit in and out for testing.
Most kit is hardwired in for a permanent connection
Boot lace ferrules. Stops the cable core from getting cut by the terminal clamping screw. Also stops stray strands of cable from shorting together when you’ve not hit the hole correctly.
Looking at the Renogy DCC50S and my solar panel and it seems they are incompatible
SPECIFICATIONS
Size 1310x670x30mm
Weight (Kg) 9.5
Watts per day (W) 1007
Amp hours per day (A) 47.52
Vmp (VDC) nominal voltage 22.9
Imp (A) nominal current 7.31
Voc (V) 27.5
Isc (A) short circuit current 6.77
So assume I could still buy it to use as alternator charge only and have a separate MPPT also connected to the battery at the same time?
SPECIFICATIONS
Size 1310x670x30mm
Weight (Kg) 9.5
Watts per day (W) 1007
Amp hours per day (A) 47.52
Vmp (VDC) nominal voltage 22.9
Imp (A) nominal current 7.31
Voc (V) 27.5
Isc (A) short circuit current 6.77
So assume I could still buy it to use as alternator charge only and have a separate MPPT also connected to the battery at the same time?
For those of you running the Renogy 50A DCDC MPPT unit, two questions. How are you connecting the negative side up? Are you going directly to the chassis or to a bus bar thats also connected to the leisure battery? Or are running seperate connections? Or something else I am not seeing?
Question 2, are you seeing/hearing electrical noise in your system?
The reason for my question. I have been running this for a while and seemingly problem free. I recently upgraded my head unit to a Kenwood with an external amp and reversing camera. The electrics seem really "noisey" with alternator wine (which wasnt present without the amp) and interference on the camera view (which was present before the amp was introduced).
I know there are a lot of moving parts but my gut says that the Renogy might be quite noisey. I am looking for pervious experience before I start to pull things to bits and start to loose my sanity.
Fingers crossed its an easy fix.
Question 2, are you seeing/hearing electrical noise in your system?
The reason for my question. I have been running this for a while and seemingly problem free. I recently upgraded my head unit to a Kenwood with an external amp and reversing camera. The electrics seem really "noisey" with alternator wine (which wasnt present without the amp) and interference on the camera view (which was present before the amp was introduced).
I know there are a lot of moving parts but my gut says that the Renogy might be quite noisey. I am looking for pervious experience before I start to pull things to bits and start to loose my sanity.
Fingers crossed its an easy fix.
stoic
Member
Hello dellmassive @co and many thanks for so great tutorials! Yesterday I got lucky and noticed one accessories battery fitted under the drivers seat of my t6, and was wondering where can I source one of these piggy-backed relays, company went bankrupt since your post. What's even the name of this thing in proper english.
Idea is to replace it with a Victron 12/12/30 DC DC and some lithium battery, is there something good and cheap on aliexpress..
Idea is to replace it with a Victron 12/12/30 DC DC and some lithium battery, is there something good and cheap on aliexpress..
The company didn't go bankrupt as far as I know but Travelvolts retired. I don't think anyone makes an equivalent dummy relay cable currently.
First bit of my leisure battery, dc-dc and solar complete….
I used 4AWG wire for all positive and negative from van battery and to hook it all up.
Had the van on idle for about 1.5 hours to fully charge the Fogstar 105ah.
Whilst using all 50a from the alternator into the Renogy, the wire from the van battery to fuse and then to the Renogy input got hot to the touch and the insulation lost its stiffness.
Is this right?
I reduced down to 40a and it seemed better.
Thoughts?
You're being a bit hard on the battery at a sustained 50amps, Fogstar recommend closer to 30amps per 100ah capacity.
Downrate the DC-DC to 30amp and everything will run cooler and happier, save the high current for those occasions you really need to charge the battery hard.
Downrate the DC-DC to 30amp and everything will run cooler and happier, save the high current for those occasions you really need to charge the battery hard.
I wouldn’t expect 4awg (25mm^2) cable to get hot to the touch passing 50A.
This graph gives a general idea of temperature rise vs current for different wire sizes and it indicates that the temperature rise should be negligible.
Temperature Rise by Current | ISRayfast
Rayfast offers high-performance harness component products combined with technical sales advice in the sectors of Aerospace, Defence, Motorsport and Naval Marine sectors, as well as many others.
www.is-rayfast.com
A high resistance due to a bad connection / crimp?
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