willyuk

Hi All,
the other day I found that one of the 40 amp fuses on my MPA safe parallel charge board had blown. Now I can think of nothing that might have caused this apart from the last time I used it I was storage charging 3 lipos and I think 2 of them were down to 40% and one was at 90% when I started. They seemed to charge OK but the next time I tried the board the fuse had gone on one of the ports. Anyone any ideas what I might have done? I never knowingly had a short circuit, no sparks or nastys and the batteries seem fine.
Also I have managed to replace the fuse but what a pain, my soldering is not the most skilful, I managed to get the old fuse out with no problem but cleaning the board so the new one would fit was really difficult even using solder wick. In the end I had to clean the two slots with a knife. Anyone have a simple way to clean the old slots??

thanks
Al

trax de max

the higher voltage battery tried to dump a lot of energy into the lower pack, The fuse protected it and may of stopped a lipo fire from happening.

willyuk

Thanks traxs, I thought that might be the case. Mind you it does say on the board that batteries can be in different states of charge! Clearly not THAT different.

trax de max

i think 0.2V is reasonable difference. I don't know what others use but that works for me.

chuckk2

"clean the old slots" Break, cut or grind the plastic fuse body and remove. The general idea is eventually to remove one fuse pin at a time.
Solder wick works better if you get rosin flux, thin it with "White Lightening" and dip the end or about an inch of the wick
in the thinned flux. Use an iron with enough thermal mass to rapidly heat the solder joint, and remove the pin.
Use another piece of the wick with thinned flux to clean the excess solder. A heated vacuum desoldering iron is also useful.
There is also such a thing as a desoldering pump. You cock it, heat the solder, place the Teflon tip over the melted solder, and press the release.