I successfully moved from Nimh to Lipo a few years back and had no problem so far (touching wood !) but I was told the Life are safer to use when sailing on the sea.
The chemical composition is different in that both are lithium but the Lipo is polymer vs the Lifepo4 is iron phosphate.
What I don’t know is if there is a real difference when in contact of sea water ? and if so which one is the safest ?
Any of you have any experience with these when sailing on saltwater ? good or bad
Hi,
the chemistry is inside the sealed package. If it will come in contact with water you have a problem anyway. In this case, the cells are broken …
Don’t worry about the chemistry (btw, I do prefer LiFePO cells, because they are less sensitive than LiPos with regard to charging/discharging behaviour), but try to keep your cells dry. Otherwise some corrosion may occur. This is more probable in sea water which is more agressive than sweet water.
thanks I didn’t know they were sealed inside - they look soft ‘ish’ as they don’t come in the hard case in those small size - my V6 is perfectly dry so no worries that way but I was curious though cos a friend told me to use lifepo instead and I really want to know if they really are safer.
Hi,
one of the safety problems of Li cells is, that if you damage the package, they might burn. This may happen, if the contents of the cell comes in contact with air. Unless the package is damaged nothing will happen (if treated correctly during charging/discharging …). As far as I now, LiPos will burn more easily when damaged than LiFePO4 cells.
A second issue is the thermal runaway which will usually not happen in a LiFePO4. Overload of a LiPo (e.g. during charging) may result is a significant heating of the cell which may accelerate the chemical processes in the cell and therefore increase the self heating … until it burns. LiPos are therefore quite sensitive to wrong treatment. The thermal runaway is more or less excluded in a LiFePO4 due to the different chemistry.
Due to that, LiFePO4s are safer than LiPos, indeed.
thanks Joachim, this is good information indeed - touching wood as so far so good but I always balance charge and also check the balance with a lipo checker balancer and only charge them at a rate of 1C and regardless of the max discharge rate I know the max pull from the winch is far lower then that figure so I am not “pulling” to much on the battery.