What size battery charger???

[joelyn]

Bought a 12v 18Amp battery to operate my mobility lift on the back of my truck.. Looking for a small battery charger to recharge the battery after 5 or 6 uses.... Have a big 12v charger for the garage but don't really want to carry that around when we go camping...
So what would be a small charger that I could use to top off my deep cycle battery every few days? Not sure what amps I should look for or not really sure what to look for.
Any suggestion would be appreciated..
THANKS.

[wa8yxm]

YOu need about a six amp Smart charger if it's a lead acid

AGM or other chemistery may (or not) be able to recharge faster

I'd go with one of the battery tender models myself for that size.

[pianotuna]

Hi Landy,

I believe the lifts may be designed descend without power. My "motion" bed has that feature but does require a pair of 9 volt batteries (a la transistor radio size) to do so.

[landyacht318]

I wonder how much juice that wheelchair lift consumes and for how long.

It's just a 35$ battery but it would certainly last longer if recharged more often than every few days.

If the battery were to die mid lift or lowering, I'd want some sort of backup method to raise and lower it, and this 'emergency' method would likely also provide some charging while the engine is running. Which might then allow driver to never put this AGM battery on a charger, which at least has a chance to get it near or to full charge, as the vehicle's voltage regulation never will, not even on a multi state roadtrip.

If both charging sources were employed the battery would be happier for even longer.

Mex in another thread, intending to respond to this one, brought up a 14.00v 7 amp power supply that looks like an inline power brick for a laptop. If it were actually 14v with 7 amps of output it would work pretty well.

while 7 amps is well above the 5.4amp maximum charge amps listed on the UB12180 battery, I regularly exceed that on the same battery, and by a good percentage.

I looked for such a 7 amp 14v dc power supply quickly, but they all came in over the price of the amazon linked charger whose '3 stages' could work better and be safer with less risk of overcharging should it be left on for too long, but instead would likely drop to float way too soon.

I have noticed that my 18AH AGM the amps will taper at absorption voltage to the 0.1 amp region, bottom out for 15 minutes, then start rising.
I suspect if I were to leave the charging source going once amps begin rising at absorption voltage, they would continue to do so while the battery heats up and this could perhaps lead to thermal runaway.

These little AGMS are not built like a mini Lifeline AGM.

[Lwiddis]

“Looking for a small battery charger to recharge the battery after 5 or 6 uses....”

Daily full recharging will extend battery life.

[RJsfishin]

Just use any maintainer charger 0f 1 amp 0r more
Or USE ANY 6 amp smart charger that you probably already have. Those batteries last a long time no matter how you charge them, Just keep them charged as soon as possible after discharging. And what about a small solar charger connected all the time

[pianotuna]

You may wish to use a trik-l-start unit to keep the "lift" battery charged.

[joelyn]

landyacht318 wrote:
It is an 18 Amphour capacity AGM battery. Likely the UB12180 rebranded as Mightymax.

https://powerwerx.azureedge.net/productattachments/D5745.pdf

Ideally, for maximum possible battery longevity, if it were discharged to 50%, or ~12.2 rested volts, one would apply about 5 amps until voltage reaches 14.5 to 14.9v then hold that voltage until amps taper to 0.09 amps at which point it would be considered fully charged.

Anything less than this, such as whatever voltage the alternator is allowed to maintain by the vehicles voltage regulator, likely into the mid 13's not too long after engine starting, is going to slow charging and be far from ideal for recharging of it, but any charging is better than no charging.

I have this mightmymax 18AH AGM battery, the same 35$ battery.

Not sure how much effort you want into perfectly recharging a 35$ battery for maximum longevity. Good enough is subjective opinion.

If you want a small sized charger. I'm not really sure what user friendly product to recommend.

These 18AH AGM batteries often come inside lead acid jumper packs and often these simply have single voltage 0.5 amp chargers inside of them that look like a wall wart. Very similar looking to some battery tender maintainers. These are far from ideal for recharging these AGMS, yet these jumper packs still seem to be able to do their job for a few years anyway, if regularly plugged and not allowed to self discharge too far.

Something like this could be more than 'good enough'. I have Zero experinece with this particular product, I just saw it is about 5 amps and 'should' be able to get a 50% depleted 18Ah agm battery back near the full range in about 4 to 5 hours.

https://www.amazon.com/dp/B07G98SN92/ref=sspa_dk_detail_3?psc=1&pd_rd_i=B07G98SN92&spLa=ZW5jcnlwdGVk...

Again I am not vouching for the efficacy, function, or durability of the linked charger. It simply has a small physical size as requested, and is just under the maximum 'recommended' 5.4 amp charge rate of the 18Ah mightmax battery(Ub12180)

Yes that is pretty much the same battery just by MIGHTY MAX. that charger u listed looks like it might be just what I want to maintain it and charge it every few days.
Again thanks to all for the suggestions, ANOTHER QUESTION ANSWERED.
THANK U ALL....

[landyacht318]

It is an 18 Amphour capacity AGM battery. Likely the UB12180 rebranded as Mightymax.

https://powerwerx.azureedge.net/productattachments/D5745.pdf

Ideally, for maximum possible battery longevity, if it were discharged to 50%, or ~12.2 rested volts, one would apply about 5 amps until voltage reaches 14.5 to 14.9v then hold that voltage until amps taper to 0.09 amps at which point it would be considered fully charged.

Anything less than this, such as whatever voltage the alternator is allowed to maintain by the vehicles voltage regulator, likely into the mid 13's not too long after engine starting, is going to slow charging and be far from ideal for recharging of it, but any charging is better than no charging.

I have this mightmymax 18AH AGM battery, the same 35$ battery.

Not sure how much effort you want into perfectly recharging a 35$ battery for maximum longevity. Good enough is subjective opinion.

If you want a small sized charger. I'm not really sure what user friendly product to recommend.

These 18AH AGM batteries often come inside lead acid jumper packs and often these simply have single voltage 0.5 amp chargers inside of them that look like a wall wart. Very similar looking to some battery tender maintainers. These are far from ideal for recharging these AGMS, yet these jumper packs still seem to be able to do their job for a few years anyway, if regularly plugged and not allowed to self discharge too far.

Something like this could be more than 'good enough'. I have Zero experinece with this particular product, I just saw it is about 5 amps and 'should' be able to get a 50% depleted 18Ah agm battery back near the full range in about 4 to 5 hours.

https://www.amazon.com/dp/B07G98SN92/ref=sspa_dk_detail_3?psc=1&pd_rd_i=B07G98SN92&spLa=ZW5jcnlwdGVk...

Again I am not vouching for the efficacy, function, or durability of the linked charger. It simply has a small physical size as requested, and is just under the maximum 'recommended' 5.4 amp charge rate of the 18Ah mightmax battery(Ub12180)

[time2roll]

joelyn wrote:

enblethen wrote:
Why not make a power connection from your trailer plug(if equipped) to charge it while you are driving?

Sounds great but way beyond my expertise of electrical inexperience, lol..

Just tap off the 7-pin harness to get 12v + to the battery. The lift installer or an independent repair shop should be able to help if needed.

Otherwise a BatteryMinder Plus brand charger should work fine at 1.5 amps.
https://www.batterystuff.com/battery-chargers/12-volt/0-4amps/bm1500.html

[Harvey51]

What does 18 amp mean?
If it is the current drawn from the battery when in use, it needs to be multiplied by the time in hours it is in use per day to get the energy used in amp-hours. Then you could look for a charger that delivers that amount of energy in the time it will be charging the battery. If the charging time is ten times as long as the lifting time then the charger needs one tenth of the 18 amps.

[joelyn]

enblethen wrote:
Why not make a power connection from your trailer plug(if equipped) to charge it while you are driving?

Sounds great but way beyond my expertise of electrical inexperience, lol..

[enblethen]

Why not make a power connection from your trailer plug(if equipped) to charge it while you are driving?