Cheap 72V charger

[monkeychops]

Sorry if this has been asked many times before. I've spent a while looking but failed.

This continues from my thread over on the ebike general discussion http://endless-sphere.com/forums/viewtopic.php?f=3&t=44743

I have a 8 lipos configured in a 12S 4P2S setup which I am bulk charging with a meanwell clone. I am thinking of buying 4 more bricks and going to 18S. I thought maybe I could wire up the packs so that under discharge they are are in a 4P3S arrangement. 3 seriesed sets of 4 in parallel, if you get me. Giving 18S, or 75.6V peak. But I wondered if I could also *at the time time* wire them (with suitable parallel harnesses) so they are arranged 6P2S, so I can charge them at 48V *without unplugging anything*. I don't think this is possible, without shorting a battery. I guess this is why I haven't found anyone that has done this!?

So this boils down to finding a suitable bulk charger. My MW clone was about £30 shipped. I realise it's full of cheap components that may well fail at any time. But I was hoping to find a suitable solution, as cheap, or nearly as cheap for charging 18S.

Really grateful for any suggestions.

If all else fails, I will buy 4 more 3S bricks to make 63V peak and then I can at least charge with a MW clone. Less top speed though :-(

 

[Jeremy Harris]

Put two 36V Meanwells in series. Been done a few times here and if one of them is fitted with Fechters little current limit mod board (http://endless-sphere.com/forums/viewtopic.php?f=31&t=36958) then it makes for a pretty good CC/CV charger.
You could probably just get a 24V Meanwell and hook it up to your existing 48V charger if you can accept that the max charge current will then be a fair bit lower.

 

[monkeychops]

It does seem that most people are connecting their chargers in series. Or unplugging the packs before parallel charging.
Bms battery seem to do a 72v charger but with shipping it would be $83 :-(

I charge at my desk in the office. Not keen to have anything too odd looking (like 2 MW clones in series) on display.

 

[kentlim26]

I have ordered One lipo charger from greentime aliexpress. Said 3 days later will be shipped to me, and indeed, greentime from China did really ship me On Sunday! my charger cost USD43 with fast shipping to me. The max volts will reached 71v 3amps to do a charging for 17cells 10amps, I will get this charger lip , next few more days and i will try them out. using balancer medic. the rest of 2cells of few few packs will be go with the charger B6AC.

The charger itself 71v 3amps cost USD29.00. I think price not so expensive so I go for a try!
tomorrow, I will go and collect my 17cells 10amps from my post office early morning. So this week I will find out, how this charger will work for my 17cells 10amps. Initially, I ask him to do a charger for lipos 18cells, I changed my mind to set the charger for 17cells, at 17cells I still can get a top speed at least 60km/h.

 

[miuan]

don't get a bmsbattery charger for on desk charging. the charger's fan is pretty loud. i got one from e-bikefactory on ebay and it's been nearly silent.

 

[monkeychops]

don't get a bmsbattery charger for on desk charging. the charger's fan is pretty loud. i got one from e-bikefactory on ebay and it's been nearly silent.

I can't find that eBay user. Can you post a link?

 

[miuan]

http://myworld.ebay.de/e-bikefactory?ssPageName=ADME:X:CEME:1181

Use the ebay contact form. The nickname is Stephy.
They can do any voltage you need, up to 20S lipo / 36S SLA.
I've recently bought from them like this, because the charger wasn't listed on ebay anymore.
The price was about 40-45 USD delivered by slow mail.
Apparently the charger is low quality, but is crazy light for its power output.
The housing is ABS, not alloy, so it weighs only about 300 grams and still does 84V/2.5A without overheating.
Also the fan is very silent compared to alloy KP chargers like those found at bmsbattery and other places.
There are no pots inside to set voltage and current, but the sellers can do it for you.

 

[EbikeWizard]

i could also use a good 72v charger but it is for SLA 72v 12ah
anybody got one that i could buy?

 

[miuan]

i could also use a good 72v charger but it is for SLA 72v 12ah
anybody got one that i could buy?

The ones I use for 20S lipo packs have the same cutoff voltage as 72V SLA chargers = 84 volts.