Generic charger mod for Sans and similar.

Nealh

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I have a few various chargers for 36v batteries but most are Sans branded black plastic bodied ones.
A couple are spot on and read 42v output, however another couple I have read 42.8v output so I set about adjusting them which was quite easy.

In this pic the plastic blue square is the Voltage regulator and is marked VR on the pcb, in the factory it is set and a blob of silicone rubber is gobbed on to it, just like the white stuff at C30 adjacent to it. You have to scrape/peel this off to allow your small screwdriver to make the adjustment, voltage range I found was 40.6v min to 50.2v max. Now I have a couple spare chargers all giving an accurate output.
DSCF0047.JPG



On the lid below I marked and drilled a 6mm hole directly above said VR, so now any adjustment can be made much easier in the future. I now have four chargers that all have the same output. The oblong window is for the charge led.

Theoretically you could adjust the voltage output lower to 41.5 or 41v, however you may end up with unbalance cell groups as the BMS doesn't carry out balancing at these lower voltages.
DSCF0049.JPG
 
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anotherkiwi

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Ohhh! a big kiss on the cheeks for that. Much cheaper making a 12S (50.4v) charger from a spare 42v one than having it flown in from China!

Yes you said 50.2v and I said 50.4v but I think that 0.2v is within balance tolerances...
 

cyclebuddy

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This guy suggests changing that 1k pot to a 5k:

https://www.yousun.org/archives/398#more-398

I've seen so many circuit variations of this "same" Sans SSLC084V42 model charger now I'm beginning to wonder if any two are exactly the same... but the caps are always only rated at 50v which might be a bit risky for a 12S pack.
 

Nealh

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For 12s the two 50v cans in the view could be swapped out for 63v ones. The big one for the mains is 400v is out of view under the aluminium roof.
 

Nealh

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The 5k VR max output is too low for 12s so futile changing it out. The guy in the link did it so that it could work 9 to 11s.
 
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The chargers in aluminium cases that you get from BMSBattery and places like that have a big range of adjustment.I've turned 36v ones down to 24v and up to 48v. I think they go a lot further than that.
 

liaiming

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42V Charger can not be modified more than 50V, because the capacitor voltage is only 50V.
More than 50V please use another charger.Or replace the high-voltage capacitor.
 

Nealh

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I am slowly going over to 13s but still using my 36v packs (until they are no longer viable) coupled with 3s booster packs ( from cannibalising a 13ah oxygen battery) so still using my 42v Sans and a cheap 3s charger from ebay.

Looking ahead for when I replace my batteries with dedicated 48v /13s ones, I will to start with mod of a couple of the 42v Sans. For a few pounds new 63v caps are cheap to get hold of and if needed the potentiometer isn't expensive either.
 
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Nealh

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Modding for 48v might be more aggro then it's worth as not only will need 2 470uf 50v caps replacing also 3 smaller 47uf 50v caps need replacing as well, possibly some other smaller component's also may not be up to extra voltage required.
New dedicated chargers are quite cheap £7.50 - £16.
 

Nealh

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This guy suggests changing that 1k pot to a 5k:

https://www.yousun.org/archives/398#more-398

I've seen so many circuit variations of this "same" Sans SSLC084V42 model charger now I'm beginning to wonder if any two are exactly the same... but the caps are always only rated at 50v which might be a bit risky for a 12S pack.
You may be right also component wise as well.
2 of my Sans adjust up to 50.2v but another identical looking one doesn't it only goes 45.6v max.
 

Nealh

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Ohhh! a big kiss on the cheeks for that. Much cheaper making a 12S (50.4v) charger from a spare 42v one than having it flown in from China!

Yes you said 50.2v and I said 50.4v but I think that 0.2v is within balance tolerances...
You may be ok for 12s as the spec for the caps say there is a 20% margin either way so for 0.2v over might well work as well as the balancing.
 

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