[DaveBlack]

Hi all, what dc-2-dc or battery to battery chargers are you using in your conversions?

I had a 96v to 13.1v charger but I am running the car at 120v and it has blown up...

Struggling to find sources that produce anything near what I need...

Just needs to take the 120vdc source and output 13.1v(ish) for the lead acid battery to keep it topped up.

Any suppliers / products anyone can recommend?

Thanks

Dave

 

[john61ct]

Highly recommend Vicor but usually sold as a board-level component, e.g. V150A15xxx

they get expensive as a finished standalone.

 

[john61ct]

For complete standalone, Brusa is the best, Kelly is OK.

Cost depends of course on the current output needed.

If you can get into the below 30V input range cheaply, then the DCDC units designed for yachts & campers will give very precisely regulated output stages, usually in the 20-60A range.

Sterling, Kisae maybe even cheap Renogy, many other brands.

 

[DaveBlack]

Thanks, ill look up those names.

Guess I could use one cell to drive the dc-dc charger @ 40v which would lower the complexities and cost of the charger.

Problem is that one cell would drain quicker than the others in series. Guess I could wire all the batteries in parallel too and use that to charge, could do without having to do that wiring tho!

Dave

 

[john61ct]

Guess I could use one cell to drive the dc-dc charger @ 40v which would lower the complexities and cost of the charger.



Problem is that one cell would drain quicker than the others in series.

Yes you do **not** want any such imbalances in normal cycling usage, it will have a huge impact over time, likely greatly reduce longevity.

The bank is only as good as the weakest cell/group.

> Guess I could wire all the batteries in parallel too and use that to charge, could do without having to do that wiring tho!



Dunno what you mean, but yes you don't want to dis/connect sub-bank elements any more frequently than necessary, usually just for SoH testing or manual rebalancing.

 

[john61ct]

Could you link to your 96v to 13.1v charger?

 

[Tremelune]

How much power from the 12v battery do you use between charges of the traction battery? You could just put a $25 12v tender on it when charging the traction pack...

 

[DaveBlack]

How much power from the 12v battery do you use between charges of the traction battery? You could just put a $25 12v tender on it when charging the traction pack...

Yeah could do, although the 12v car battery is pretty heavily used. Mainly the power steering is fully electric and run off the 12v battery. Really need to keep it topped up otherwise within a few miles it does start to struggle.

Dave

 

[john61ct]

Best to actually get the average Ah consumed per hour, from all sources

and make sure the converter supports double that without strain.

The 12V battery is in effect just a buffer.