Amp Hour Battery capacity in your van?
- Thread starter Boyntonstu
- Start date
Help Support Van Living Forum:
VanKitten
Well-known member
Yes...except the ones I ordered are encased in aluminum instead of plastic. The reason is that aluminum will allow for better heat exchange.
CampingOdyssey
Member
- Joined
- Apr 9, 2017
- Messages
- 22
- Reaction score
- 5
Thanks for the recommendation John61CT, those look perfect for the job. Let me see if I understand this correctly, with the AbsorbV set at 13.8V maximum and FloatV around 13.2V it will do a bulk charge up to about 91% of the batteries capacity, then a slower charge up to about 95%, never fully charging it? Are these the same settings that should be programed into a solar charge controller to use with a Lifepo4 battery? (Any recommendations for a good solar charger that would allow you to program the correct settings?)
I checked out the owners manual for the Sterling Procharge Ultra but didn't see any specs on the starter battery. I'm a bit concerned because my starter battery / alternator may not be functioning properly (although I've been driving the van daily for 5 years without any issues). Do you know what voltage the starter battery has to be at for the Procharge Ultra to begin charging the lifepo4 battery? Also, could having a faulty starter battery / alternator hurt the battery charger or Lifepro4 battery in any way?
As far as usable Amp Hours, I read that a Lifepo4 battery will give you 80% discharge for around 2000 cycles, while a AGM will give you 20% discharge at around 1500 cycles. Under those conditions it would seem that a 100ah Lifepo4 is really the equivalent to 400ah AGM, with an extra 500+ cycles of life, making the lifetime cost of the two types of batteries pretty similar. On a Lifepo4, will setting the AbsorbV at 13.8 max and FloatV at 13.2V be enough to give you a significant amount more cycles, or are there other sorts of practices that should be considered? Is the 80% discharge too much for a lifepo4, if so what do you think is best? Is it recommended to take the charge down to a certain level and then recharge it (up to 95%) in the same manner every time? Or is it ok to be inconsistent... as in, taking it down to 60%, charging it to 80%, than down to 50% up to 90% etc? Also, are Lifepo4 batteries good for someone who isn't a full time van dweller. If the battery is only used for a couple weeks at a time every few months, is that sort of inconsistent use bad for the battery? Should it be disconnected during times on non use?
Sorry for all the questions, I really appreciate everyone's help.
I checked out the owners manual for the Sterling Procharge Ultra but didn't see any specs on the starter battery. I'm a bit concerned because my starter battery / alternator may not be functioning properly (although I've been driving the van daily for 5 years without any issues). Do you know what voltage the starter battery has to be at for the Procharge Ultra to begin charging the lifepo4 battery? Also, could having a faulty starter battery / alternator hurt the battery charger or Lifepro4 battery in any way?
As far as usable Amp Hours, I read that a Lifepo4 battery will give you 80% discharge for around 2000 cycles, while a AGM will give you 20% discharge at around 1500 cycles. Under those conditions it would seem that a 100ah Lifepo4 is really the equivalent to 400ah AGM, with an extra 500+ cycles of life, making the lifetime cost of the two types of batteries pretty similar. On a Lifepo4, will setting the AbsorbV at 13.8 max and FloatV at 13.2V be enough to give you a significant amount more cycles, or are there other sorts of practices that should be considered? Is the 80% discharge too much for a lifepo4, if so what do you think is best? Is it recommended to take the charge down to a certain level and then recharge it (up to 95%) in the same manner every time? Or is it ok to be inconsistent... as in, taking it down to 60%, charging it to 80%, than down to 50% up to 90% etc? Also, are Lifepo4 batteries good for someone who isn't a full time van dweller. If the battery is only used for a couple weeks at a time every few months, is that sort of inconsistent use bad for the battery? Should it be disconnected during times on non use?
Sorry for all the questions, I really appreciate everyone's help.
Wow.
> with the AbsorbV set at 13.8V maximum and FloatV around 13.2V it will do a bulk charge up to about 91% of the batteries capacity, then a slower charge up to about 95%, never fully charging it?
First off, the batt mfg, a BMS vendor, and **you** define where on the charge curve "100%" is. Most important is to remember from the bank's POV there is no reason to get up to that full. Just consider it a maximum not to be exceeded.
My definition of 100% is, Stop Charging when 13.9V is reached, OR keep charging at 13.8V until current acceptance falls to .02C, or 2A per 100AH, then Stop Charging.
Float of 13.2V is pretty close to Stop, since the resting voltage when full is higher.
Note the bank should never sit Full, only go up there if you've got loads that will immediately start the down cycle.
> Are these the same settings that should be programed into a solar charge controller to use with a Lifepo4 battery? (Any recommendations for a good solar charger that would allow you to program the correct settings?)
Yes, all charge sources, electricity is electricity. Nearly all decent chargers have that level of adjustability, for suggestions start a new thread.
> I checked out the owners manual for the Sterling Procharge Ultra but didn't see any specs on the starter battery. I'm a bit concerned because my starter battery / alternator may not be functioning properly (although I've been driving the van daily for 5 years without any issues). Do you know what voltage the starter battery has to be at for the Procharge Ultra to begin charging the lifepo4 battery?
Sorry, no idea what you mean, the two should not be connected at all IMO, and we're talking here about a shore charger?
> Also, could having a faulty starter battery / alternator hurt the battery charger or Lifepro4 battery in any way?
I suppose, depends on your overall system design? Each should have their own charge source, and the alt would need a lot of mods to be suitable for LFP.
> As far as usable Amp Hours, I read that a Lifepo4 battery will give you 80% discharge for around 2000 cycles, while a AGM will give you 20% discharge at around 1500 cycles.
No, down to 5% is fine, BMS should prevent further discharge or you risk your investment of thousands of dollars in LFP.
AGM, any lead, is 50%, so LFP is nearly double usable.
> an extra 500+ cycles of life, making the lifetime cost of the two types of batteries pretty similar
Lots more than that if coddled, unknown for now, and ROI decades out is very risky, especially for a beginner.
> On a Lifepo4, will setting the AbsorbV at 13.8 max and FloatV at 13.2V be enough to give you a significant amount more cycles, or are there other sorts of practices that should be considered?
The mfg docs gives all the other ways to murder them quickly. Full discharge, charging in freezing temps are a couple.
> Is the 80% discharge too much for a lifepo4, if so what do you think is best? If you look at the voltage vs SoC curves, the "shoulders" at both ends are best avoided.
> Is it recommended to take the charge down to a certain level and then recharge it (up to 95%) in the same manner every time? Or is it ok to be inconsistent... as in, taking it down to 60%, charging it to 80%, than down to 50% up to 90% etc?
No consistency required, do what is convenient.
> Also, are Lifepo4 batteries good for someone who isn't a full time van dweller. If the battery is only used for a couple weeks at a time every few months, is that sort of inconsistent use bad for the battery? Should it be disconnected during times on non use?
Yes, because they prefer to be at low SoC when not being cycled, but are scrap if allowed to fully discharge. Periodically add 5% to counteract self-discharge. Keep cool and dry but not freezing.
> with the AbsorbV set at 13.8V maximum and FloatV around 13.2V it will do a bulk charge up to about 91% of the batteries capacity, then a slower charge up to about 95%, never fully charging it?
First off, the batt mfg, a BMS vendor, and **you** define where on the charge curve "100%" is. Most important is to remember from the bank's POV there is no reason to get up to that full. Just consider it a maximum not to be exceeded.
My definition of 100% is, Stop Charging when 13.9V is reached, OR keep charging at 13.8V until current acceptance falls to .02C, or 2A per 100AH, then Stop Charging.
Float of 13.2V is pretty close to Stop, since the resting voltage when full is higher.
Note the bank should never sit Full, only go up there if you've got loads that will immediately start the down cycle.
> Are these the same settings that should be programed into a solar charge controller to use with a Lifepo4 battery? (Any recommendations for a good solar charger that would allow you to program the correct settings?)
Yes, all charge sources, electricity is electricity. Nearly all decent chargers have that level of adjustability, for suggestions start a new thread.
> I checked out the owners manual for the Sterling Procharge Ultra but didn't see any specs on the starter battery. I'm a bit concerned because my starter battery / alternator may not be functioning properly (although I've been driving the van daily for 5 years without any issues). Do you know what voltage the starter battery has to be at for the Procharge Ultra to begin charging the lifepo4 battery?
Sorry, no idea what you mean, the two should not be connected at all IMO, and we're talking here about a shore charger?
> Also, could having a faulty starter battery / alternator hurt the battery charger or Lifepro4 battery in any way?
I suppose, depends on your overall system design? Each should have their own charge source, and the alt would need a lot of mods to be suitable for LFP.
> As far as usable Amp Hours, I read that a Lifepo4 battery will give you 80% discharge for around 2000 cycles, while a AGM will give you 20% discharge at around 1500 cycles.
No, down to 5% is fine, BMS should prevent further discharge or you risk your investment of thousands of dollars in LFP.
AGM, any lead, is 50%, so LFP is nearly double usable.
> an extra 500+ cycles of life, making the lifetime cost of the two types of batteries pretty similar
Lots more than that if coddled, unknown for now, and ROI decades out is very risky, especially for a beginner.
> On a Lifepo4, will setting the AbsorbV at 13.8 max and FloatV at 13.2V be enough to give you a significant amount more cycles, or are there other sorts of practices that should be considered?
The mfg docs gives all the other ways to murder them quickly. Full discharge, charging in freezing temps are a couple.
> Is the 80% discharge too much for a lifepo4, if so what do you think is best? If you look at the voltage vs SoC curves, the "shoulders" at both ends are best avoided.
> Is it recommended to take the charge down to a certain level and then recharge it (up to 95%) in the same manner every time? Or is it ok to be inconsistent... as in, taking it down to 60%, charging it to 80%, than down to 50% up to 90% etc?
No consistency required, do what is convenient.
> Also, are Lifepo4 batteries good for someone who isn't a full time van dweller. If the battery is only used for a couple weeks at a time every few months, is that sort of inconsistent use bad for the battery? Should it be disconnected during times on non use?
Yes, because they prefer to be at low SoC when not being cycled, but are scrap if allowed to fully discharge. Periodically add 5% to counteract self-discharge. Keep cool and dry but not freezing.
road_ahead
Member
- Joined
- Aug 23, 2017
- Messages
- 17
- Reaction score
- 0
Ok, back on subject. I'll start:
3 x Group 31 AGM - 315Ah
3 x Group 31 AGM - 315Ah
frater secessus
Well-known member
2x Duracell GC2 = 220Ah
jonyjoe303
Well-known member
- Joined
- May 18, 2017
- Messages
- 690
- Reaction score
- 94
2x 110 ah 12.8 volt lifepo4 batterypacks
1x 94 ah li-ion 11.1 volt batterypack,
1x 65 ah li-ion 11.1 volt batterypack,
1x 33 ah li-ion 11.1 volt batterypack,
1x kinitek 102 ah agm,
1x fullriver 28 ah agm,
1x 35 ah agm
Lately I been getting the urge to add another 110 ah lifepo4 to the modest collection that I have. I feel I need more power.
As far as charging the lifepo4 with a solar controller, with my ecoworthy 20 amp mppt (not lithium capable), I had to set the absorb voltage to 15.5 volts and the float to 14.5 volts (the highest it will go) to fast charge it. If I set it to 14.4 volts, it will take days or weeks to fully charge. Even set to 15 volts it was only charging at 8 amps.
If the absorb is set to 13.8 volts, even in full sunlight you might get 3 amps of charge power. The controller will see a full battery and just trickle charge it.
Lifepo4 Fully charge voltage is 14.6 volts and fully discharge voltage 11.2 volts.
1x 94 ah li-ion 11.1 volt batterypack,
1x 65 ah li-ion 11.1 volt batterypack,
1x 33 ah li-ion 11.1 volt batterypack,
1x kinitek 102 ah agm,
1x fullriver 28 ah agm,
1x 35 ah agm
Lately I been getting the urge to add another 110 ah lifepo4 to the modest collection that I have. I feel I need more power.
As far as charging the lifepo4 with a solar controller, with my ecoworthy 20 amp mppt (not lithium capable), I had to set the absorb voltage to 15.5 volts and the float to 14.5 volts (the highest it will go) to fast charge it. If I set it to 14.4 volts, it will take days or weeks to fully charge. Even set to 15 volts it was only charging at 8 amps.
If the absorb is set to 13.8 volts, even in full sunlight you might get 3 amps of charge power. The controller will see a full battery and just trickle charge it.
Lifepo4 Fully charge voltage is 14.6 volts and fully discharge voltage 11.2 volts.
I'm thinking the nomenclature for amp-hours is inconsistent...they have it for 20 hour or 8 hour or whatever.
What's the standardized way to compare, isn't kilowatt-hours better since it takes into account the decrease in voltage?
What's the standardized way to compare, isn't kilowatt-hours better since it takes into account the decrease in voltage?
Yes, you see all kinds of crazy AH ratings on the small power packs. For marketing purposes, their amps are quoted at lower voltages like 5V USB output, and/or they just flat-out lie.
Standard is a 20-hour rate at 12V discharge, so powering a 5A or 60W load for 20 hours before empty.
A true 100AH LFP bank would be four of these http://www.electriccarpartscompany.com/100Ah-CALB-UL-Certified-Batteries, costs a grand delivered, and bare cells are just the start, need BMS functionality to protect your investment.
The little power packs, and hobbyist DIYs made from welded 18650 cells, anything "easily portable" weighing under 20 pounds, should not IMO count as House banks
But if so then yes, measure in watt hours to compare them to each other.
Standard is a 20-hour rate at 12V discharge, so powering a 5A or 60W load for 20 hours before empty.
A true 100AH LFP bank would be four of these http://www.electriccarpartscompany.com/100Ah-CALB-UL-Certified-Batteries, costs a grand delivered, and bare cells are just the start, need BMS functionality to protect your investment.
The little power packs, and hobbyist DIYs made from welded 18650 cells, anything "easily portable" weighing under 20 pounds, should not IMO count as House banks
But if so then yes, measure in watt hours to compare them to each other.
Sailing VANessa
Well-known member
- Joined
- Sep 23, 2016
- Messages
- 63
- Reaction score
- 0
2 x Vmaxtanks 12v, AGM, 125 ah each in parallel for total 250ah.
