Stihl MSA200c battery charging issue after inactivity.

[openspaceman]

20 minutes ago, Macpherson said:

 

I don't really know with these Stihl batteries, I've done it regularly with AA and AAA's and I appreciate your caution, 

Maybe buy a new battery and then try to boost the old one from an independent 36v source... three 12v batteries in series maybe ?

Cheers.

@kram seems to be on the ball with these batteries and it will be interesting to see what @Fatboy2017 finds.

 

A big difference between lithium ion batteries and the dry cells and lead acid ones we are used to in cars and toys is their very low internal resistance, so the chargers need current limiting as well as the correct maximum voltage.

 

If this battery pack charges then well and good and @Fatboy2017 can use it again.

 

If not, and allowing that @kram thinks the output from the battery is directly connected to 36V,with no switching by the BMS, I will be interested if the tool works with it when charged by other than the Stihl charger.

[Macpherson]

2 hours ago, openspaceman said:

@kram seems to be on the ball with these batteries and it will be interesting to see what @Fatboy2017 finds.

 

A big difference between lithium ion batteries and the dry cells and lead acid ones we are used to in cars and toys is their very low internal resistance, so the chargers need current limiting as well as the correct maximum voltage.

 

If this battery pack charges then well and good and @Fatboy2017 can use it again.

 

If not, and allowing that @kram thinks the output from the battery is directly connected to 36V,with no switching by the BMS, I will be interested if the tool works with it when charged by other than the Stihl charger.

 

Hi, yep I don't make any claims to know much about this tech but I'll also be interested to know if the battery can be boosted enough to be charged.

I also wandered if even just putting it somewhere warm would help.

There's really nothing to be lost in trying to boost a duff battery but I know I wouldn't risk damaging a new battery.

Just last week I had my AP300 battery charging through a watt meter as I'm building up a list of what all my appliances use in order to get a handle on potential off grid requirements and I was quite surprised how many watts were measured,   It started charging using around 250 watts and gradually increased to nearly 700 before fully charged.

 

[Fatboy2017]

I will get a new battery at the start of the new year. I am a bit windy about connecting the new battery to the old one but in theory it shouldn't harm the new one but maybe it will trigger a fault in the new one? Is there any merit in connecting a single 18v battery to the old one? Or 2 x 18v in series? I have loads of them!

The consensus seems to be that if the battery are completely discharged then you have to reset the BMS with the Stihl software, but I've not actually had this confirmed yet as the Stihl software is very expensive, plus I suppose the quickest and easiest method is to chuck a new battery on the thing. Mark at Skyland said he would look into putting a battery on his diagnostic but for sure it will not be high on his priority list! I think as these battery things get more popular it would benefit from understanding the functions, but the manufactures also have to want to do this. My brother has a 12 month old e-bike which he stupidly pressure washed, water got in and it blew a diode or whatever in the BMS board. No help from the manufacturer - just buy a new battery!! It's fixable if you recognise the diode, but it burned and can't read anything on it. Tried to find a hobby electronics' person but don't know one. In the past I used to send all my faulty car music centre's to a guy who was an electronics' wizard at an RAF base, he fixed everything!!  If you need manufacturer's kit to remove codes or switch thing on again then we're snookered!!

[kram]

Just to repeat if you were to jump it from a other power source, it does not need or want to be 36v and not directly to another battery.

 

Once its about 20-30v total, the Stihl charger shouldnt have anything to complain about, it will be within the normal range of a discharged battery.

 

It should be done in a way thats current limited. You can get cheap current limiting boards off amazon for nearly nothing. You should be able to find something on how to set it up on YT. You want to start with only 100miliAmps until it gets to 20v or so then let the proper Stihl charger finish it off.

 

18v battery or mains power supply -> limiter board -> dead battery.

 

[Fatboy2017]

Got it!