An alternative to a heavy 12V/7A SLA battery in your yak…

[keza]

I got this on:
http://www.ebay.com.au/itm/150770246295 ... 1439.l2649
Bit more $$ but in a hard plastic case rather than just the plastic wrap.

[Drew]

Thanks guys, do they get supplied with an Aussie adapter?

[bildad]

Thanks guys, do they get supplied with an Aussie adapter?

Just twist the pins with a pair of pliers so that they line up and they work fine.

[Drew]

Thanks guys, do they get supplied with an Aussie adapter?

Just twist the pins with a pair of pliers so that they line up and they work fine.

mmm... I tell people off at work for doing that.....

[MrX]

Drew, some of the retailers do - I just asked, and they threw in an Aussie adapter in for free. The one they gave me is more compact than the universal adapter from the local newsagent.

[mmmBEER]

Hi All,

I've just received my 9800mAh battery courtesy of eBay for my Garmin Echo 100. I think it's the same as the one Murd originally posted about. Thanks for the waterproofing photos & ideas. I have also used a klip lock container and the Jaycar cable gland to keep the battery nice & dry. My fuse is also inside the container and I have a waterproof plug from Jaycar so the whole lot can be removed for charging. I'm hoping to get it mounted in the hull of the Prowler tomorrow. I agree about trying to keep it up out of any water which may be sloshing about inside the hull, so I bought some adhesive Velcro patches to hopefully mount it up on the underside of the deck. The only thing is the packet of the Velcro says it may not adhere to all plastics...will have to wait & see. Each patch is rated to 3kg, so it should be strong enough. I'll post some photos up if it all works.

[GlenelgKiller]

I will try and take a photo of my battery install later because it works a treat. Grabbed a chunk of high density foam from clarks, angle cut the edges to match the sides of the hull in the bow and siliconed it to the sides leaving a gap beneath so any water would run underneath in the bottom of the hull. Before glueing in i drove a couple of slots right through and threaded a long ribbon of velcro through each. Battery is waterproofed in a clip lock with a modified rubber cork plugging up the cable exit and i glued 4 patches of velcro to the lid. So the clip lock with battery in sits atop the foam and the velcro wraps up and onto the lid secured by the patches. Also can bundle all the loose cable in when securing the velcro.

Had this out a couple of times in the surf and it works beautifully!

[Occy]

I got this on:
http://www.ebay.com.au/itm/150770246295 ... 1439.l2649
Bit more $$ but in a hard plastic case rather than just the plastic wrap.

How is the new battery going Keza? Any shots of how you fitted it out?

[paulo]

Dredging up an old thread here as I have a question regarding charging Li-ion batteries from a solar panel and another about the amount of output current available.

On extended yak camping trips I have a 1aH wp solar panel and charge regulator I use to charge two 9aH SLAs in series. At night I use this to recharge cameras, phones, vhf radios, etc.
This setup charges four radios and three 5v devices via usb ports all at once. I cant recall measuring the total current draw when charging multiple devices. Charging a single vhf radio draws 600mA when flat.

Changing to a Li-Ion battery will reduce weight and bulk. Im looking at a 20Ah battery.
Most of them have this in their specs Output: 12.6V DC, 350mA.
Does this mean they will only deliver a max output current of 350mAh when charging multiple devices?
Taking twice as long to charge the vhf as when done from an SLA?
The sounder draws 600mAh so Im guessing this isnt what it means.

What does the special charger do?
Is there a chance of explosion if the special charger isnt used or will it just reduce the life of the battery?
The solar regulator should stop over current draw during charging.
Has anyone charged a Li-ion from a solar panel?

TIA

[indiedog]

Paulo, I can't say I can really help you much but a couple of comments.

What I worked out from my trip with the solar panel, is charge what you can during the day when you are getting the max benefit out of your solar panel. I attempted to charge things back at camp when the sun was lower, trees were in the way and so on. I was only running one 7Ah battery (sounder draw of 300mA and panel producing max 300mA) and I think it'd be better to hook up phones etc to charge directly from the battery with the solar panel connected and getting good sun. This way you are getting the benefit of both battery and solar panel at the same time. If you are using the batteries only at night to recharge phones and radios then they start off depleted in the morning when you fire up the sounder. So the panel will be trying to do two jobs of running the sounder and recharging. If your panel gets a max of 1000mA (so realistically a bit less) and your sounder is using 600mA then there's possibly not a lot left to charge the battery. If there's a way you can hook up your radio to the battery on the trip home then that might assist. Note I'm not sure what the capacity of the radio and phone batteries are so don't know what they draw from your main battery.

As to the Li-on battery, my only understanding is they are much more sensitive to overcharging. Not sure if the regulator on the panel is sufficient to safeguard against this but I suspect it's not made for it. The other thing is the Li-on batteries are killed by salt water instantly. I did consider one but decided against it due to its sensitivities.

[paulo]

Brad, the 18aH of batteries is left at Base Camp every day and gets the benefit of full sun all day. I have a third battery that runs the sounder and swap it out every day. The panel pumps out 900mA in full sun and had no trouble charging the two 9aH SLAs every day. These in turn charged everyone's radio, etc every night. It really did work very well.

CHanging to Li-ion will reduce the weight of the three SLAs (7-8kg) down to around 1-2kg. A big saving in a yak. Im not too worried about water ingress. I havent had water in any of my SLAs before and the size and weight of the LI-ions mean I can mount the battery higher up in the yak. I would transport the 20aH battery in a dry bag and leave it on shore as described.

My question is more around the charging of SLAs from a solar panel. The battery has an inbuilt switch to protect against overcharge. Im guessing this means it will stop accepting charge once at full even though the solar panel is still pumping it out.
The regulator I have is this
Charge Controller
[list=]100% SOLID STATE: All power switching is done with MOFSET's. No mechanical relays are used
Rated 4.5 Amps @ 12 volts
Temperature compensation
Battery charge regulation
Wires are rated for outdoor use, size 16 AWG, with Hypalon Insulation[/list]

This suggests it isnt a problem
Charge currents with Li-ion are less critical and can vary widely. Any charge will do, including energy from a renewable resource such as a solar panel or wind turbine. Charge absorption is very high and with a low and intermittent charge, charging simply takes a little longer without negatively affecting the battery. The absence of trickle charge further helps simplify the charger.

Most devices draw 600mA when flat. This drops according to the charging curve for SLAa as the battery gets close to full charge. I noticed someone said earlier that Li-ions wouldnt drive higher powered 12v devices.
Does an output max current of 350mA mean it wont drive my sounder that needs 5-600mA to run or charge my radio which will need a similar current to charge.

[MrX]

G'day Paulo,

"I noticed someone said earlier that Li-ions wouldnt drive higher powered 12v devices.
Does an output max current of 350mA mean it wont drive my sounder that needs 5-600mA to run or charge my radio which will need a similar current to charge."

I don't know anything about charging from solar panels, but I've been using Li-Ion batteries to power my sounder for years - using the standard included charger. They don't work for high current draw 12v things like bilge pumps (for a bait tank), but mine have worked fine for electrical items.

They are so small and light (and cheap) I just take a few with me fully charged for long trips.

The battery cuts out automatically before over-charge, or when shorted, so should be safe for your panel.

The batteries I use are rated:
- Maximum charge current: 2A
- Maximum discharge current: 5A

That's ample for any sounder or radio.

An output max current of 350mA sounds pretty weak to me - might be for specialist use?

"The other thing is the Li-on batteries are killed by salt water instantly. I did consider one but decided against it due to its sensitivities."

Give one a go, Indie - you'll love the space/weight saving, ease of dry storage on yak (and in the car). I've only killed one - wore out the thin wires.

[indiedog]

Paul, that's a bit clearer on how you manage the 3 batteries now and that sounds like a good way to do it. If you managed the Li-ions the same way then I can't see why it wouldn't work. Yes the max output current needs to be sufficient to charge whatever it is you are charging but the batteries on devices such as mobile phones etc are pretty small.

If your sounder draws 600mA (must be a mofo of a sounder!) then could you drop to 3 x 4.4Ah batteries? You'd get 7 hours out of each for the sounder, while the other two are charging. Possibly a 4.4 would have enough grunt to charge your phones etc? Would need to check that but the 4.4's would be about half the weight of the 9's I think.

Give one a go, Indie - you'll love the space/weight saving, ease of dry storage on yak (and in the car).

I bought a 2.2Ah SLA battery and it's 900 grams as opposed to 2.5kg for my 7Ah SLA so a good weight saving. My sounder draws around 300mA so I get a full day out of the 2.2Ah battery. Only time I will use the 7Ah again is for the multi day camping trips. Given my panel should put out what the sounder uses I should be able to survive with the 2.2 and will trial it with the 7 as a backup. Only hassle is I get very few opportunities for multi-day trips now.

[MrX]

"I bought a 2.2Ah SLA battery and it's 900 grams..."

Try a 4.8 Ah li-on. Weighs 178 grams, and smaller than a ciggie packet (and about the same cost - delivered with charger).

http://www.ebay.com.au/itm/330370477043?ssPageName=STRK:MEWNX:IT&_trksid=p3984.m1497.l2649

Get two for your multi day trips

[indiedog]

"I bought a 2.2Ah SLA battery and it's 900 grams..."

Try a 4.8 Ah li-on. Weighs 178 grams, and smaller than a ciggie packet (and about the same cost - delivered with charger).

http://www.ebay.com.au/itm/330370477043?ssPageName=STRK:MEWNX:IT&_trksid=p3984.m1497.l2649

Get two for your multi day trips

Sounds good. Available with 240V plug?