Battery, trickle charger, isolator...

[eavega]

So in the process of getting my '95 SPX running, I went with a less expensive lead-acid battery until I was sure that everything was in good running order. I figure I'll move to an AGM when the flooded cell I bought inevitably dies. In the meantime, I make it a habit to keep the batteries on my various devices (generator, boat, motorcycles, etc) on trickle chargers so they are always topped off. I've read warnings against doing this on PWCs as the trickle chargers can damage electric components. Keeping the battery out of the ski is not my preferred option (although that's how I have it now during the winter). To make matters a little more complicated, Where I keep the ski there is no easy access to power. This leads to several questions:

1. For my boat, I keep the battery topped off with one of these http://www.northerntool.com/shop/tools/product_200655383_200655383
Would this work for the PWC battery completely wired up in my PWC? The specification is that it has a max output of 2.5 Watts, but I have measured the voltage as high as 15V when in direct sunlight. I didn't know if there was a risk of blowing something out.

2. Would putting an inline switch or battery isolator be advisable or recommended? That way, I could isolate the electronics while I am charging the battery.

3. Am I overthinking this and I won't damage anything using either the 2.5 watt solar panel or a plug-into-the-wall battery tender?

Thanks in advance for any suggestions you all can offer

-Eric

 

[WaveriderX]

I use the noco genius g750 for my pwc I have used it while the battery was in the ski with no problems but It really gets used in the winter more works great hold the battery at 13.50 volts it's only .75 amp it just a maintainer but does everything I need it to noco also makes a solar pad that I would work to if you can't get power where you ski is at hope this helps a little bit

https://no.co

 

[Coastiejoe]

With my tender I do not remove any wires. If I use the charger, I simply remove the ground.

A switch or isolater would do what you want if you'd rather not remove the battery wire..

 

[Sportster-2001-951C-Stock]

I say if you're going to charge the battery you need some type of disconnect to isolate one terminal of the battery from the MPEM while charging is taking place.

Your charger should be at least a two-step charger whch takes battery voltage up to about 14.8 volts then switches to float mode voltage about 13.2-13.4, or allows the battery to soak down to 12.7 then switches in and out of 13.2~13.4V float mode

If you have a constant 15 volts across your battery it's being overcharged, more likely will damage the smaller batteries faster.

One more thing to add, I've seen more batteries die an early death as a result of too much love from an el-cheapo or old manual charger zapping them to death than I've seen die a premature death due to lack of love.

If you have a really good charge strategy (not Harbor Freight IMO) you can leave them going without damaging the battery. I still want the energy savings so I use a good quality float charger powered through a lamp timer so it's only powered about 10 min/day.

This is the one I've been using for over a decade, it still works great and has never damaged any batteries (some of my batteries are older than the charger and they are one by one being replaced just now).

https://www.batterystuff.com/battery-chargers/12-volt/marine-chargers/BTW022-0150.html

 

[eavega]

I actually have a couple of Battery Tender Jr maintainers which I am very happy with. I've kept my boat battery very well maintained for over 7 years on one of these along with the Coleman solar panel during the season when the boat is out of the garage. Of course, that battery doesn't ever see too much of a drop in charge since the boat has an alternator that charges the battery while its running. I've also had good luck with the Northern Tools Battery Minder on my motorcycle batteries Those have spent a significant amount of time on the tender as my wife and I haven't gotten out on our bikes as much as we like over the last few years. I was really more concerned with the MPEM on the ski than the battery. Given that its a PITA to connect up the terminals (i've already dropped one of the terminal screws into the abyss of the bilge), I think I am going to go with an isolator switch to segregate the electronics, and carefully monitor the solar panel to make sure its not dropping too much voltage on the battery. Thanks again for all the suggestions and information.

-E

 

[Sportster-2001-951C-Stock]

Good choice, you really must protect the MPEM b/c these particular ones are very sensitive to brief over voltage spikes often reached during the proper (momentary) topping charge that most good automatic float chargers will do. I've seen some actually for just a moment reach over 15V at the peak detection before dropping into float mode. That's just too close to the margin for this particular MPEM, pretty widely known. Yeah, you might not have a problem but many do, it's pretty common.

Also, occasionally during charging using shore power there can be voltage spikes during atmospheric events that are capable of damaging the electronics of any vehicle, so for prolonged unattended or questionable periods it's wise to eliminate the possibility in my experience. Just do it and avoid the possibility, no harm done.

For retrieving hardware from the bilge I use a magnetic device on a wire for fishing non-stainless hardware, compressed air can help retrieve stainless hardware.