I have a battery tender which is a slow trickle charger. I didn't buy it for this purpose it's just something i already have. I have a idea to use it with my in dash factory 120 power source. This would be temporary until i can get an isolator. I realize this probably isn't going to work very well unless i drive alot. I'm not full time and i just want to power a maxair fan. Is there a better charger i can get or could i just use what i have until i get solar and an isolator? I also have the wrong battery. I have a yellow top optima which i believe is just a starting battery. I only need it to work for 1 night and later im going on a 4 night trip. I plan to use a battery brick for my phone and have everything fully charged before i leave. I think ill be fine for the 1 night but what can i do for the 4 night besides idle the van?
What type of shore power chargers do you use?
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Are you wanting to plug in to external AC (shore power) and keep the vehicle starting battery charged with the battery tender while the fan is running?
Or are you trying to directly power the fan with the battery tender plugged into the AC power outlet in the dash?
The first option will probably work, the second will not.
The fan can be powered directly from the starting battery for 1 night, but the vehicle will need to be started and allowed to run for a while each day if you want to run the fan all night for 4 nights.
Or are you trying to directly power the fan with the battery tender plugged into the AC power outlet in the dash?
The first option will probably work, the second will not.
The fan can be powered directly from the starting battery for 1 night, but the vehicle will need to be started and allowed to run for a while each day if you want to run the fan all night for 4 nights.
Keep track of your battery condition for $12.
Do you have a vehicle with an extra 12V receptacle? If not, you can get duplex adapters.
https://www.walmart.com/ip/Equus-In...75035&wl11=online&wl12=15137663&wl13=&veh=sem
Do you have a vehicle with an extra 12V receptacle? If not, you can get duplex adapters.
https://www.walmart.com/ip/Equus-In...75035&wl11=online&wl12=15137663&wl13=&veh=sem
The yellow top will be my house battery powering the fan. For one night im hoping it will be ok even though its a starting battery. For the 4 night trip ill possibly have shore power but if not i want to charge the house battery from the dash while im driving. If i take the AH of the battery and divide it by 5 (amps of fan draw) that should give me the hours it will run it correct? Being a starting battery i have less than the normal 50% to discharge.
Ok...the Yellow Top IS your house battery, I thought you said it was your starting battery.
Yes, you can actually use the dash 120v receptacle to power a Battery Tender, hooked up to a house battery while driving to help maintain the house battery.
It will not charge it fast, so it might take many hours of driving to recover a full charge.
But, it will certainly be better than no charging at all, and if it is what you have, give it a try.
Just remember that the Optima batteries are expensive, and if you run it down too low, it might not recover...
BTW, the Maxaire fan probably draws about 1 to 2 amps on low, and maybe up to 5 amps on high.
Yes, you can actually use the dash 120v receptacle to power a Battery Tender, hooked up to a house battery while driving to help maintain the house battery.
It will not charge it fast, so it might take many hours of driving to recover a full charge.
But, it will certainly be better than no charging at all, and if it is what you have, give it a try.
Just remember that the Optima batteries are expensive, and if you run it down too low, it might not recover...
BTW, the Maxaire fan probably draws about 1 to 2 amps on low, and maybe up to 5 amps on high.
Spaceman Spiff
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Scout said:
(Amp draw of fan) X (Hours you intend to run the fan) = Amp-hours you will remove from your battery.
(AH removed from battery) ÷ (Amps supplied by trickle charger, usually 0.75A) = Number of hours you need to drive to 'almost*' replace charge.
* There are always losses so you need to put back more than you take out.
* Once your battery gets to 80%, it will take at least 2.5 hours to get to 100% with any charger.
One night should be OK unless you draw down more than 50% as you will be able to recharge the next day on shore power.
Four days will depend on how much you take out vs. how much you put back in. It is a dual purpose battery so should be able to handle not being fully recharged for four days.
jimindenver
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While on Shore power or while using my generator I have the converter in my trailer and a 30 amp Meanwell power supply with a 50 amp analog meter and clips. Neither of these are inexpensive and I got lucky picking up my little generator for $152.
It would be more efficient to charge the house battery from the 12V ciggy receptacle by using something like these:
https://www.bedbathandbeyond.com/st...MIx6rBwKKe2QIVTlt-Ch2cFg7-EAQYASABEgJBu_D_BwE
https://www.jbtoolsales.com/clore-a...MIsJ_ex6Ke2QIVhYF-Ch13_gRHEAQYASABEgITHvD_BwE
Or you could wire a female receptacle to the battery and not use clips.
The downside would be that you may pop the fuse in the lighter circuit if the battery is depleted a lot.
https://www.bedbathandbeyond.com/st...MIx6rBwKKe2QIVTlt-Ch2cFg7-EAQYASABEgJBu_D_BwE
https://www.jbtoolsales.com/clore-a...MIsJ_ex6Ke2QIVhYF-Ch13_gRHEAQYASABEgITHvD_BwE
Or you could wire a female receptacle to the battery and not use clips.
The downside would be that you may pop the fuse in the lighter circuit if the battery is depleted a lot.
While driving your alternator is putting out charging current suitable for your battery.
Using a tiny-amp mains charger running from an inverter is cray-cray.
But putting high amps through a ciggie port is unsafe.
Find an unused or lightly used circuit to tap into from your fusebox and charge your batt off that. Make sure to disconnect when you're not driving so you don't run the starter down.
More ideal for later is a direct run with robust wire, VSR/ACR connecting the two batts, proper fusing.
Using a tiny-amp mains charger running from an inverter is cray-cray.
But putting high amps through a ciggie port is unsafe.
Find an unused or lightly used circuit to tap into from your fusebox and charge your batt off that. Make sure to disconnect when you're not driving so you don't run the starter down.
More ideal for later is a direct run with robust wire, VSR/ACR connecting the two batts, proper fusing.
jimindenver
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Honestly, a pair of jumper cables between the house battery and you vehicle battery while running the engine every night will put more into the house battery in minutes than the trickle charger will in a day of driving. Trickle charges are intended to keep a battery from self discharging, not charge it. Some can not even overcome the drain of the car alarm/radio. It will suck taking it out every night but you will have power when you put it back in AND you will not destroy your battery.
The yellow top is like a marine battery, duel duty, neither use ideal. However, depending on the size you have, 27 or 31. The smaller one, D27F is rated at 66 amp hour. That means it was tested at 3.3 amps for 20 hours to dead. You could reasonably run a 3 or 4 amp fan for about 10 hours to 1/2 dead. With a heavy enough jumper from your vehicle battery you could conceivably recharge with a day's driving. To charge using mains power, get a real battery charger, not a charge maintainer.
Just what is your "in dash 120 volt outlet"?
Some day when you have a better battery bank you would like some kind of marine smart charger to plug into the mains.
Just what is your "in dash 120 volt outlet"?
Some day when you have a better battery bank you would like some kind of marine smart charger to plug into the mains.
ratfink56
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I have read elsewhere that deep cycle batteries are happiest when charged with a three stage charger. Supposedly this is the only way to get a full charge. FYI
Trebor English
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Previously I posted a thread about Max Fan amps.
Maxxair 00-05100K MaxxFan. It is the non remote 10 speed variety. The amps did vary with wind gusts.
off .005
1 .13
2 .20
3 .30
4 .45
5 .63
6 .865
7 1.13
8 1.46
9 1.89
10 2.65
Upgrade from a maintainer to a charger and start the 4 day trip with the battery charged. This manual charger, $32, 6 amp, can work if given enough hours:
https://www.amazon.com/gp/aw/d/B0009IBJBM
To use a manual charger a volt meter is necessary.
A fat wire manually connected, disconnected, from the alternator with lots of driving also could charge the battery. The maintainer will not.
Once you start with a full battery, with the fan on speed 5 for 8 hours at .63 amps you will use 5 amp hours per night. Four nights is 20 amp hours. A 66 amp hour battery should tolerate that.
After the four day trip recharge the battery right away.
Maxxair 00-05100K MaxxFan. It is the non remote 10 speed variety. The amps did vary with wind gusts.
off .005
1 .13
2 .20
3 .30
4 .45
5 .63
6 .865
7 1.13
8 1.46
9 1.89
10 2.65
Upgrade from a maintainer to a charger and start the 4 day trip with the battery charged. This manual charger, $32, 6 amp, can work if given enough hours:
https://www.amazon.com/gp/aw/d/B0009IBJBM
To use a manual charger a volt meter is necessary.
A fat wire manually connected, disconnected, from the alternator with lots of driving also could charge the battery. The maintainer will not.
Once you start with a full battery, with the fan on speed 5 for 8 hours at .63 amps you will use 5 amp hours per night. Four nights is 20 amp hours. A 66 amp hour battery should tolerate that.
After the four day trip recharge the battery right away.
Spaceman Spiff
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ratfink56 said:
NO. A lead acid battery is 'happiest' when it is charged at the manufacturer's specified charging voltage until it will only accept about 1 amp per 100 AH of capacity. One doesn't need a 3-stage charger for that. What one needs is a charger that is set/can be set to the correct voltage. After that a maintenance charge voltage of ~ 13 1/2 volts will keep it at full charge. But a healthy LA battery will loose only ~5% per month (internal discharge), so a maintainer is not necessary unless the battery is going to sit for a while or has small parasitic loads attached to it.
frater secessus
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I'm counting three stages in your answer there, Spiff.
Perhaps we could agree on something like "a correctly-featured and -configured three-stage charger", which would cover the points you mention.
Perhaps we could agree on something like "a correctly-featured and -configured three-stage charger", which would cover the points you mention.
frater secessus
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Spaceman Spiff
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frater secessus said:
Lead acid batteries go through up to three stages when charging, I was challenging the need to be '[font=Verdana, Arial, sans-serif]charged with a three stage charger'[/font] to accomplish it.
I use a simple variable voltage bench power supply to charge my batteries. It provides up to 25 amps @ 14.4 volts; the batteries control the voltage and amps they will accept. Configurable multi-stage chargers are expensive; my power supply cost <$100.
jimindenver
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My adjustable voltage, 30 amp Meanwell power supply was $100 as was the 36 amp Megawatt before it. They work great on smaller banks but not my three Lifeline 8-Ds. The bank chewed up and spit out the Megawatt and was trying to do it to the Meanwell too. My bank can take ten hours at full output and they just are not meant for it.
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