Battery Vehicle Society

I just noticed these 36V 30A chargers on eBay and wondered if anyone here has any experience with them?
http://cgi.ebay.co.uk/36V-30A-Single-Phase-Battery-Charger-HIGH-FREQUENCY_W0QQitemZ150232792915QQihZ005QQcategoryZ97185QQrdZ1QQssPageNameZWD1VQQcmdZViewItemQQ_trksidZp1638Q2em118Q2el1247

According to the data sheet: "Different charging methods and characteristics can be selected by means of the microprocessor control", but it doesn't give any more information about the different methods or how they're selected.
I plan to upgrade my motorcycle to Li ion in the near future and would like to know if this charger could be set up for a CCCV charge with cutoff at 44.5V.

I've emailed Curtis but haven't got a reply yet.

Cant see why it shoulnt charge a Li-ion set , but then you'd still need a BMS for the cells wouldnt you

ChrisB

I'm going to say this once and once only, not because I think you would do this, but just in case anyone else only half reads the thread!

NEVER charge lithium with a bog standard Lead charger

Now I know Malcolm that you're a sensible enough sort of chap and very knowledgeable not to do that, but I just wanted to get that disclaimer there!

My car uses a modified transformer based charger for my lithiums. I've wired one of the outputs from the BMS to a solid state relay across the charger side of the secondary coil from the transformer. When the battery voltage reaches the maximum allowed for each cell the BMS's output goes logic low, opening the relay and closing off the charging.

I would assume you could do this with any charger for lithium if you have the appropriate measures in place to stop the charge process when maximum voltage has arrived.

Have you got a Curtis charger already? Which one are you thinking of?

Can it be controlled externally?

Nikki,
The charger in question is the Curtis Figaro, This is fully capable of charging more or less and type of battery including Li, Pb sealed as well as flooded, Ni-cad etc. If you would like a full data sheet let me know and I will email one over to you.
They really are a great piece of kit and at the kind of money they are being sold for on ebay, well what can I say --
Go Grab Yourself a Bargain

Good points Nikki, but please don't call me sensible

Just to stress what you said: Lithium ion need to be charged to around 3.7 to 4.2V per cell depending on the chemistry. LiFePO4, which I plan to use, should be charged at the lower end of this range. Unlike lead acid, lithium ion cells must not be left on the charger for any length of time once they've reached this final voltage, as it will seriously reduce the life of the cells, and can actually cause some chemistries to spontaneously ignite (not LiFePO4, as far as I know). Lithium should always be used with some form of cell protection to prevent overcharging and overdischarge.

What I wanted to know is whether the Curtis charger can be adjusted for a specific end voltage and whether it can be set to cut off automatically when it reaches that voltage. From what Dave says, it sounds as if it will.

You can charge Li-ions on anything really its all down to monitoring and if you dont mind flying by the seat of your pants they will be fine, Alan Ward runs his fiesta on Li-ions and has no BMS what so ever and monitors the batteries manually to my knowledge

ChrisB

...And I've just ordered a nice NG3 to charge mine. It will be charging at the maximum allowed for the cell type I have, but it will mean a recharge time of two hours....

Nikki

What's the maximum depth of discharge you've got from your Thundersky pack. If I remember right it's a 4kWh pack? I know you've got one of those all-singing Reap BMSs so have you ever taken it right to the low voltage cutoff just to see?