Hmm, so should I be afraid of the batter in my Zodiac? According to the dissection http://www.nerys.com/zodiacreview/zodbattery.html those two batteries are connected in parallel together so they are not protected for reverse polarity if one is charged less or dies sooner or whatever, f.t.a. "This band is not part of the batteries and it goes almost all the way around the cells connecting both negative terminals. Note the positive terminals face each other in the center (they are joined as well)" .

Also what damage can cause charging with lower current to less capacity? li-pol are said to have no 'memory effect' and most people think they can be charged and taken from charger anytime. Couldn't we just charge twice to workaround the timer? Sorry if this sounds stupid.


Also there are two issues - 1. degrading capacity due to less that ideal charging and 2. chance of exploding, leaking or whatever. Are we talking about 1 or 2 here? 1 can be solved by buying new batteries sooner.

I have no personal experience with the Zodiac battery, but I would guess that reverse polarity protection is built into the battery cells instead of the charger in that case. Unfortunately, that's not normally the case (since it's not normally necessary).

It's true that lithium batteries have very little memory effect compared to other battery chemistries, but no battery type can completely eliminate the memory effect. Since the charge timer may kick in the battery may only be partially charged. Charging again may work, but could potentially cause the temperature sensor to terminate the charge since all batteries heat up to some degree when charging, and the amount of temperature increase is proportional to the duration of the charge. This could be solved by allowing some time between charges, but isn't the whole idea of a second battery to increase uptime? Seems like you'd be better off just keeping a spare on hand and swapping it when the first one dies. Yes, I know you would lose hot-swap ability, but what's so important that you can't shut down for a minute or so to swap batteries?

Yes, #1 could be solved by purchasing new batteries sooner, but do you really want to spend money on new batteries more often than is absolutely necessary? As for #2, the possibility is remote (and obviously worst-case) but not impossible or unheard of.