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Solar Charging or? Electrical Gurus I need your help

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I leave the last week of August for a 3500 mile, unsupported, mostly dirt ride through the western states on many of the famous trails of the west. Our trip will require at least 8 days of moto camping consecutively and 20 days on the road.

I have a medical condition called Sleep Apnea which requires that I use a device known as a CPAP & it has a battery that will require charging along the way on this trip. Therein lies the problem.

A little background about my DRZ. Over the years it has had multiple electrical problems as a result of a very poor patch wiring job by the PO. This resulted in the bike having three different stators, two R/R's and a new wiring harness.

After many diagnostic forays using Nobles techniques in the FAQ's I finally isolated the intermittent problem. It ended up being the infamous corroded connector from the R/R. Now the bike is charging normally.

What I am seeking is a work around for charging the battery of my CPAP

by not over utilizing the bikes charging system.

Right now I am planning to wire in a cigarette plug off the SAE plug (connected to my battery) that I use to hook up my trickle charger. This in turn will charge the CPAP battery. However, I don't want to over tax my charging system and have been considering strapping a small solar charger to my Dirt Bagz duffle to do the charging. However, after reading the specs I am pretty sure the battery won't completely charge using this method.

For this trip I plan to flip the headlamp plug 180* in order to utilize the existing headlamp switch to turn off the headlight when I can (in the boonies). This in turn will free up some electrons for charging. Other than that I could use some recommendations as to what I can and should be using to accomplish charging the external battery as well as the bikes battery.

Other mods designed to free up charging capacity include an Edge Two Tail light with the 12 O'Clock integrated blinkers, and gsxr blinkers up front on the cowling. This said, it is a distinct possibility that in higher elevations I may need to use my heated grips. Yeah I know, I'm a *****.

This is THE BATTERY I will need to charge.

So, can any of you electrical gurus help me set this up correctly or suggest viable alternatives?

Thanks in advance

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I have one of these http://www.earthtechproducts.com/p2007.html kept my bike battery charged for 2k miles thru northern AZ and southern utah. Just unfold onto your seat whenever your at camp and it should refresh your battery enough so that it starts for you even with the drain from your devices.

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Atcr1, that's an interesting arrangement. Is it flexible enough not break when strapped to my luggage? How small does it fold for packing?

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vstrom - From what I read about the battery, the biggest concern is if you will be operating the DRZ for the required recharge time daily. 2.5 amp for 5 to 6 hr. 2.5 amps (about 35 watts) is no big deal assuming you do not have other demands on the electrical system. The stock system will support that no problem. Will you be riding the DRZ for 5 to 6 hrs daily?

Which battery will you buy and what CPAP pressure do you use? That determines how long the battery will operate your CPAP equipment. You may not need to recharge daily. How significant is it to you if you have to spend a night with no CPAP? Dead in the morning or wake up with a head ache?

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It will only take 5 to 6 hours to recharge if it is completely dead, so the required recharge will be less. It would be best to top off the charge every day. It doesn't hurt LiIon batteries. No memory effect.

The headlight draws 55 watts. The battery charger 35 watts. If the headlight is off you are still saving 20 watts.

Even with the headlight on, as Noble said the bike can handle that extra 35 watts no problem.

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vstrom - From what I read about the battery, the biggest concern is if you will be operating the DRZ for the required recharge time daily. 2.5 amp for 5 to 6 hr. 2.5 amps (about 35 watts) is no big deal assuming you do not have other demands on the electrical system. The stock system will support that no problem. Will you be riding the DRZ for 5 to 6 hrs daily?Yes, we plan on 7-8 hours days in the saddle

Which battery will you buy and what CPAP pressure do you use? That determines how long the battery will operate your CPAP equipment. You may not need to recharge daily. How significant is it to you if you have to spend a night with no CPAP? Dead in the morning or wake up with a head ache?

My pressue is set at 10H2O, which with this battery should provide 11 hours usage depending on minor factors, yes, it is very important I wake alive, without a head ache.
It will only take 5 to 6 hours to recharge if it is completely dead, so the required recharge will be less. It would be best to top off the charge every day. It doesn't hurt LiIon batteries. No memory effect.

The headlight draws 55 watts. The battery charger 35 watts. If the headlight is off you are still saving 20 watts.

Even with the headlight on, as Noble said the bike can handle that extra 35 watts no problem.

I suppose with my prolonged electrical problems I am skidish about using the electrical system either in full or part. The battery is ordered so I plan to test to insure that the bikes system will handle it.

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Can you not camp in parks with electrical hook ups?

This is a wilderness ride. There will be a few nights in National Parks, but I want to stay out of the RV Campgrounds. The idea is to do this in a primitive fashion as much as possible. Besides, I am on a budget so $25 a night to charge a battery seems excessive.

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This is a wilderness ride. There will be a few nights in National Parks, but I want to stay out of the RV Campgrounds. The idea is to do this in a primitive fashion as much as possible. Besides, I am on a budget so $25 a night to charge a battery seems excessive.

You should be OK charging from the battery directly. You did the free power mod and all that stuff right? Also, I would suggest to getting a new battery before the trip too.

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vstrom - Sounds like a great ride. This may be a little hard to believe and maybe slowriding can conform. But it makes no difference to the electrical system if you are drawing min power or maximum power. No matter what, the RR shunts any extra generated power to ground (interconnects the yellow wires to themselves). The electrical system will hold up or not based on design not what load you put on it. If you exceed the generating capability (which you will not) it will simply result in depressed voltage and the battery will slowly die until the load is reduced to what the generator can support.

My pressure is 12 but I can do without it no problem.

slow - So Lithium batteries don't need to be cycled to full discharge before recharge? That is good to know. Everything I hear about LiIon sounds positive. I also read that they can be recharged rapidly. Wonder why 5 - 6 hr for this one? Must be the capacity of the charge circuit?

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But it makes no difference to the electrical system if you are drawing min power or maximum power. No matter what, the RR shunts any extra generated power to ground (interconnects the yellow wires to themselves).

slow - So Lithium batteries don't need to be cycled to full discharge before recharge? That is good to know. Everything I hear about LiIon sounds positive. I also read that they can be recharged rapidly. Wonder why 5 - 6 hr for this one? Must be the capacity of the charge circuit?

I know how the electrical system works by shunting but I wonder if it somehow lowers the efficiency so that less power is produced.

It is actually best to not fully discharge li-ion batteries... charge away(but for storage 40% is best).

li-ion have an issue with exploding under certain circumstances.

quick charge for Li-ion... well somewhat. Up to 1c but ussualy 5.-.7c. But also require a saturation period. Some lithium batteris (li-fe-po4) can be charged up to 10c, these are the ones used in the bike battery replacements.

Edited by jbwiden
li-fe-po4=LFP= safer changed from lipo4 which does not exist

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vstrom - Sounds like a great ride. This may be a little hard to believe and maybe slowriding can conform. But it makes no difference to the electrical system if you are drawing min power or maximum power. No matter what, the RR shunts any extra generated power to ground (interconnects the yellow wires to themselves). The electrical system will hold up or not based on design not what load you put on it. If you exceed the generating capability (which you will not) it will simply result in depressed voltage and the battery will slowly die until the load is reduced to what the generator can support.

My pressure is 12 but I can do without it no problem.

slow - So Lithium batteries don't need to be cycled to full discharge before recharge? That is good to know. Everything I hear about LiIon sounds positive. I also read that they can be recharged rapidly. Wonder why 5 - 6 hr for this one? Must be the capacity of the charge circuit?

Noble, I chose this battery for it's ability to support a full nights sleep and not end up totally discharged. My only concern is the inverter that must be used with it due to packing size. On unsupported rides space becomes an extreme issue as does concern for the subframe if one overloads the bike.

Its comforting to know that the system will endure the stress of charging the second battery, however I still feel the need for supplementary charging in the form of solar. When at higher elevations I will have to stop and switch from DRZ power to solar to charge so that I can wear a heated vest (this option to maximize available packing space).

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the solar panel may say 12 watts but that is ideal conditions... I would expect more like an average of 6 watts if used for multiple hours through the most sunny part of the day. In the evenings i would not think it would provide any use at all.

If using a heated vest and charging the li-on bat i think your best option would be to turn the headlight off.

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I think after hearing the input from y'all I am going to go ahead and get the battery and do some field testing as suggested. I will let everyone know what my voltages end up being while charging.

Thanks

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How about the cheap 2 stroke generator for harbor freight for $89.99? Just use it a couple hours a day. Its 900 watts. It may be too bulk to put on your bike though.

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It is actually best to not fully discharge li-ion batteries... charge away(but for storage 40% is best).

li-ion have an issue with exploding under certain circumstances.

quick charge for Li-ion... well somewhat. Up to 1c but ussualy 5.-.7c. But also require a saturation period. Some lithium batteris (li-po4) can be charged up to 10c, these are the ones used in the bike battery replacements.

The bike batteries are LFP which is Lithium Iron Phosphate(LiFePO4), not Lithium Polymer or Lithium Ion. Lithium Ion came about because metallic lithium was not safe in rechargeable batteries. Other variations of Lithium chemistry continue to develop. Some history can be found here http://en.wikipedia.org/wiki/Lithium-ion_battery

Most lithium batteries (not LFP) require very specific charge regulation circuitry. Li-Ion can in certain circumstances have a runaway thermal event (fire) if charged to quickly.

The c references above are capacity, so .5c means it can be charged at a current which is 1/2 its rating. Just chucked that in there for anyone reading that was scratching their head.

Edited by slowriding

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But it makes no difference to the electrical system if you are drawing min power or maximum power. No matter what, the RR shunts any extra generated power to ground (interconnects the yellow wires to themselves). The electrical system will hold up or not based on design not what load you put on it. If you exceed the generating capability (which you will not) it will simply result in depressed voltage and the battery will slowly die until the load is reduced to what the generator can support.

slow - So Lithium batteries don't need to be cycled to full discharge before recharge?

LFP batteries can be damaged if they are run below 8volts per the FAQ on www.turntechbattery.com

From the wiki link in the above post here is some info on other Lithium types:

---------------------------------------------------------------

Safety requirements

If overheated or overcharged, Li-ion batteries may suffer thermal runaway and cell rupture.[48] In extreme cases this can lead to combustion. [highlight] Deep discharge may short-circuit the cell, in which case recharging would be unsafe[/highlight].[49] To reduce these risks, Lithium-ion battery packs contain fail-safe circuity that shuts down the battery when its voltage is outside the safe range of 3–4.2 V per cell.[25][37] When stored for long periods the small current draw of the protection circuitry itself may drain the battery below its shut down voltage; normal chargers are then ineffective. Many types of lithium-ion cell cannot be charged safely below 0°C.[50]

Other safety features are required in each cell:[25]

shut-down separator (for overtemperature)

tear-away tab (for internal pressure)

vent (pressure relief)

thermal interrupt (overcurrent/overcharging)

-----------------------------------------------------------------

Unlike an alternator on a car/truck/etc which has a winding for the excitation on the rotor which can be varied by the regulator, the DRZ uses magnets. Since they are always 'on' and producing full magnetic field and thus full generation, the output has to be limited by shunting the unneeded power. On some systems it is literally shorted to ground through a zenier and dissipated as heat, but on the DRZ it is shunted internally in the stator windings by the R/R. Probably because the output is quite high for a simple short-to-ground zenier system. It is more practical to have per-phase regulation.

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Atcr1, that's an interesting arrangement. Is it flexible enough not break when strapped to my luggage? How small does it fold for packing?

dpends on the size you go with. Mine folds down to about 11x6 and only .75in thick. Stows easily in the bottom of my tankbag

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